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ASP.NET Core 2.2.1 Hosting - HostForLIFE.eu :: System.Diagnostics Useful Actions

clock October 2, 2018 09:51 by author Peter

The namespace System.Diagnostics provides a set of attributes and classes to interact with the system process, event managers, performance counts etc. This namespace can help us too in debugging jobs.

Let’s review the useful actions inside System.Diagnostics namespace.

DebuggerDisplay Attribute
DebuggerDisplay attribute drives the string format with debug screen, which shows the value of: class, properties or fields.

For this same task, it is best known override ToString method, but use DebbugerDisplay attribute is a better choice, because this does not modify the data structure as it only interacts with Visual Studio debbuger screen. Override ToString method for only this purpose can give problems because many actions in .NET takes this value for default, for example bindings in WPF.

This attribute supports delegates, properties, fields and assamblies.

Example
[System.Diagnostics.DebuggerDisplay("{ID} - {Model}- {Manufacturer} - {ProductionDate}")] 
public class Car 

    public int      ID             { get; set; } 
    public string   Model        { get; set; } 
    public string   Manufacturer   { get; set; } 
    public DateTime ProductionDate { get; set; } 
}  



DebuggerHidden Attribute
DebuggerHidden attribute prevents the compiler from stopping in constructors, methods, properties and indexers declarations.
In mentioning this later, my comment might sound lightweight, but in the practice, this can save time push key F11 in debugging.

Example
[System.Diagnostics.DebuggerHidden] 
public static List<Car> GetData() 

    var result = new List<Car>() 
    { 
        new Car{ ID = 1, Manufacturer = "Ford",   Model = "Mustang", ProductionDate = DateTime.Today }, 
        new Car{ ID = 2, Manufacturer = "Nissan", Model = "Micra"  , ProductionDate = DateTime.Today } 
    }; 
 
    return result; 
}  


Debugger.Launch

Occasionally, we can’t debug the code of a library, Service etc. because it is not accessible or we can’t add project to our solution. In this case, we can use the Debugger.Launch() method and Visual Studio opens a debug Window and we can debug its code.

When executed, the line Systen.Diagnostics.Debbuger.Launch() opens a MessageBox with the instance of Visual Studio Debugger Options.

In this window, we can choose, if we open a new stance of Visual Studio (all versions) or if we re-use an existing instance. We can debug the code, as shown below.

Conditional Attribute
Conditional attribute allows us to indicate a condition to the methods so that the compiler executes or does not execute its content. We can use it with the precompiler sentences as DEBUG.
static void Main(string[] args) 

 
    DebugMethod(); 
 
 
    Console.Read(); 

 
[System.Diagnostics.Conditional("DEBUG")] 
public static void DebugMethod() 

    Console.WriteLine("Execute Debug Method"); 
}  


It will only run if the solutions configurations are debugged.

The condition doesn’t exist for RELEASE, therefore we will use a define Directives.
Define Directives is another way to use System.Diagnostics.Conditional,
#define RELEASE_MODE 
 
using System; 
namespace SystemDiagnosticsUsefulActions 

    class Program 
    { 
        static void Main(string[] args) 
        { 
            ReleaseMethod(); 
 
            Console.Read(); 
        } 
 
        [System.Diagnostics.Conditional("RELEASE_MODE")] 
        public static void ReleaseMethod() 
        { 
            Console.WriteLine("Execute Release Method"); 
        } 
 
    } 
 
}  


These are the useful tips and traps of System.Diagnostics. They become very practical in many cases and I hope you find them useful.

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ASP.NET Core 2.2.1 Hosting - HostForLIFE.eu :: Insert Data using Uploading Excel file and upload image and set water mark

clock September 28, 2018 11:17 by author Peter

In this blog, I will show you how to Insert Data using Uploading Excel file and upload image and set water mark. Let's write the code below.

Demo.aspx
<body> 
    <form id="form1" runat="server"> 
        <div> 
            <table> 
                <tr> 
                    <td> 
                        <asp:FileUpload ID ="fu" runat ="server" /> 
                    </td> 
                    <td> 
                        <asp:Button ID ="btnupload" runat ="server" Text="Upload File" 
onclick="btnupload_Click" /> 
                    </td> 
                </tr> 
            </table> 
        </div> 
    </form> 
</body> 


Demo.aspx .cs
DataTable dt = new DataTable(); 
 
protected void btnupload_Click(object sender, EventArgs e) 

    if (fu.HasFile) 
    { 
        if (fu.PostedFile.ContentType == "application/vnd.ms-excel" || fu.PostedFile.ContentType == "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet") 
        { 
            string fileName = Path.Combine(Server.MapPath("~/localization"), Guid.NewGuid().ToString() + Path.GetExtension(fu.PostedFile.FileName)); 
            fu.PostedFile.SaveAs(fileName); 
 
            string conString = ""; 
            string ext = Path.GetExtension(fu.PostedFile.FileName); 
            if (ext.ToLower() == ".xls") 
            { 
                conString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + fileName + ";Extended Properties=\"Excel 8.0;HDR=Yes;IMEX=2\""; 
            }  
            else if (ext.ToLower() == ".xlsx")  
            { 
                conString = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + fileName + ";Extended Properties=\"Excel 12.0;HDR=Yes;IMEX=2\""; 
            } 
            string query = "Select * from [Sheet1$]"; 
            OleDbConnection con = new OleDbConnection(conString); 
            OleDbDataAdapter data = new OleDbDataAdapter(query, con); 
            data.Fill(dt); 
            int i = 0; 
            //File_Upload file = new File_Upload(); 
            for (i = 0; i < dt.Rows.Count; i++) 
            { 
                string name = dt.Rows[i]["name"].ToString(); 
                string email = dt.Rows[i]["email"].ToString(); 
                string pass = dt.Rows[i]["Password"].ToString(); 
                string mobile = dt.Rows[i]["mobile"].ToString(); 
                string state = dt.Rows[i]["state"].ToString(); 
                string city = dt.Rows[i]["city"].ToString(); 
                string photo = dt.Rows[i]["Photo"].ToString(); 
 
                string[] pathArr = photo.Split('\\'); 
                string[] fileArr = pathArr.Last().Split('.'); 
                string fName = fileArr[0].ToString(); 
                Random rnd = new Random(); 
                string fn = fName + "_" + rnd.Next(111, 999) + "_" + rnd.Next(111, 999) + ".jpg"; 
                string path = "~/photo/" + fn; 
                string pat = Server.MapPath(path); 
                Wattermark w = new Wattermark(); 
                Dal odal = new Dal(); 
                System.Drawing.Image image = System.Drawing.Image.FromFile(photo); 
                Graphics graphics = Graphics.FromImage(image); 
                Font font = new Font("Times New Roman", 42.0f); 
                PointF point = new PointF(10, 10); 
                graphics.DrawString("Tusharsangani", font, Brushes.Red, point); 
                image.Save(pat); 
                odal.fetch("insert into Registeruser (name,E_id,password,mobile,state,city,photo) values('" + name + "','" + email + "','" + pass + "','" + mobile + "','" + state + "','" + city + "','" + path + "')"); 
            } 
        } 
    }  
    else  
    { 
 
    } 

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ASP.NET Core 2.2.1 Hosting - HostForLIFE.eu :: Random Password In C#

clock September 26, 2018 11:14 by author Peter

A random password is a combination of characters, numbers, and special characters. We can generate a random password by combining random numbers and random strings.
Generate A Random Password In C# And .NET Core. The code snippet in this article is an example of how to generate random numbers and random strings and combine them to create a random password using C# and .NET Core.

The Random class constructors have two overloaded forms. It takes either no value or it takes a seed value. The Random class has three public methods - Next, NextBytes, and NextDouble. The Next method returns a random number, NextBytes returns an array of bytes filled with random numbers, and NextDouble returns a random number between 0.0 and 1.0.

Generate a random number
The following code in Listing 1 returns a random number.
// Generate a random number 
Random random = new Random(); 
// Any random integer  
int num = random.Next(); 


Generate a random string
The following code snippet in Listing 2 generates a random string with a given size. The second parameter of the RandomString method is used for setting if the string is a lowercase string.
// Generate a random string with a given size and case.  
// If second parameter is true, the return string is lowercase 
public string RandomString(int size, bool lowerCase) 

    StringBuilder builder = new StringBuilder(); 
    Random random = new Random(); 
    char ch; 
    for (int i = 0; i < size; i++) 
    { 
        ch = Convert.ToChar(Convert.ToInt32(Math.Floor(26 * random.NextDouble() + 65))); 
        builder.Append(ch); 
    } 
    if (lowerCase) 
        return builder.ToString().ToLower(); 
    return builder.ToString(); 


Creating a random password
A random password can simply be a combination of a random string and a random number. To make it more complex, you can even add special characters and mix it up.
For us, we will combine the two methods - RandomNumber and RandomString.

The following code snippet in Listing 3 generates a password of length 10 with first 4 letters lowercase, next 4 letters numbers, and the last 2 letters as uppercase.
// Generate a random password of a given length (optional) 
public string RandomPassword(int size = 0) 

    StringBuilder builder = new StringBuilder(); 
    builder.Append(RandomString(4, true)); 
    builder.Append(RandomNumber(1000, 9999)); 
    builder.Append(RandomString(2, false)); 
    return builder.ToString(); 


All of the above functionality is listed here in Listing 4. Create a .NET Core Console app in Visual Studio and use this code.
using System; 
using System.Text; 
 
class RandomNumberSample 

    static void Main(string[] args) 
    { 
        // Generate a random number 
        Random random = new Random(); 
        // Any random integer  
        int num = random.Next(); 
 
        // A random number below 100 
        int randomLessThan100 = random.Next(100); 
        Console.WriteLine(randomLessThan100); 
 
        // A random number within a range 
        int randomBetween100And500 = random.Next(100, 500); 
        Console.WriteLine(randomBetween100And500); 
 
        // Use other methods  
        RandomNumberGenerator generator = new RandomNumberGenerator(); 
        int rand = generator.RandomNumber(5, 100); 
        Console.WriteLine($"Random number between 5 and 100 is {rand}"); 
 
        string str = generator.RandomString(10, false); 
        Console.WriteLine($"Random string of 10 chars is {str}"); 
 
        string pass = generator.RandomPassword(); 
        Console.WriteLine($"Random password {pass}"); 
 
        Console.ReadKey(); 
    } 

 
public class RandomNumberGenerator 

    // Generate a random number between two numbers   
    public int RandomNumber(int min, int max) 
    { 
        Random random = new Random(); 
        return random.Next(min, max); 
    } 
 
// Generate a random string with a given size and case.  
// If second parameter is true, the return string is lowercase 
public string RandomString(int size, bool lowerCase) 

    StringBuilder builder = new StringBuilder(); 
    Random random = new Random(); 
    char ch; 
    for (int i = 0; i < size; i++) 
    { 
        ch = Convert.ToChar(Convert.ToInt32(Math.Floor(26 * random.NextDouble() + 65))); 
        builder.Append(ch); 
    } 
    if (lowerCase) 
        return builder.ToString().ToLower(); 
    return builder.ToString(); 

 
    // Generate a random password of a given length (optional) 
    public string RandomPassword(int size = 0) 
    { 
        StringBuilder builder = new StringBuilder(); 
        builder.Append(RandomString(4, true)); 
        builder.Append(RandomNumber(1000, 9999)); 
        builder.Append(RandomString(2, false)); 
        return builder.ToString(); 
    } 


The random string and random password looks like Figure 1.
Generate A Random Password In C# And .NET Core


Random password with given characters

Now, let’s say, you want to create a password that allows some specific characters only. The following code snippet in Listing 5 has a string of valid characters. The code uses this string to pick one character at a time for the password and stops at the given length. The default length of the password is 15.

private static string CreateRandomPassword(int length = 15) 

    // Create a string of characters, numbers, special characters that allowed in the password 
    string validChars = "ABCDEFGHJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789!@#$%^&*?_-"; 
    Random random = new Random(); 
 
    // Select one random character at a time from the string 
    // and create an array of chars 
    char[] chars = new char[length]; 
    for (int i = 0; i < length; i++) 
    { 
        chars[i] = validChars[random.Next(0, validChars.Length)]; 
    } 
    return new string(chars); 


Note
You can modify validChars string with the characters you allowed in the password.
Listing 6 is the complete program written in .NET Core.

using System; 
class Program 

    static void Main(string[] args) 
    {  
        Console.WriteLine(CreateRandomPassword()); 
        Console.WriteLine(CreateRandomPassword(10)); 
        Console.WriteLine(CreateRandomPassword(30)); 
 
        Console.WriteLine(CreateRandomPasswordWithRandomLength()); 
 
        Console.ReadKey(); 
    } 
 
 
    // Default size of random password is 15 
    private static string CreateRandomPassword(int length = 15) 
    { 
        // Create a string of characters, numbers, special characters that allowed in the password 
        string validChars = "ABCDEFGHJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789!@#$%^&*?_-"; 
        Random random = new Random(); 
 
        // Select one random character at a time from the string 
        // and create an array of chars 
        char[] chars = new char[length]; 
        for (int i = 0; i < length; i++) 
        { 
            chars[i] = validChars[random.Next(0, validChars.Length)]; 
        } 
        return new string(chars); 
    } 
 
    private static string CreateRandomPasswordWithRandomLength() 
    { 
        // Create a string of characters, numbers, special characters that allowed in the password 
        string validChars = "ABCDEFGHJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789!@#$%^&*?_-"; 
        Random random = new Random(); 
 
        // Minimum size 8. Max size is number of all allowed chars. 
        int size = random.Next(8, validChars.Length); 
 
        // Select one random character at a time from the string 
        // and create an array of chars 
        char[] chars = new char[size]; 
        for (int i = 0; i < size; i++) 
        { 
            chars[i] = validChars[random.Next(0, validChars.Length)]; 
        } 
        return new string(chars); 
    } 

 



ASP.NET Core 2.2.1 Hosting - HostForLIFE.eu :: Start Using HTTP Handlers In ASP.NET

clock September 19, 2018 11:48 by author Peter

First, let me explain the main purpose of using HTTPHandler. Sometimes you need to handle a specific request separately using a different method from that of a normal request. This article will explain HTTP Handler in a simple way. Let’s begin:
How can you handle any incoming HTTP request with a path “AllUsers/User.gif” by returning “Hello From HTTP Handler”.

  • Create a class file --  it could be MyHttpHandler.cs
  • Let MyHttpHandler class inherit from IhttpHandler Interface.
  • In MyHttpHandler class, implement all the methods which are found in IhttpHandler Interface.

You should do the following,
using System; 
using System.Collections.Generic; 
using System.Linq; 
using System.Web; 
namespace MyProject { 
    public class MyHttpHandler: IHttpHandler { 
        public bool IsReusable { 
            get { 
                return true; 
            } 
        } 
        public void ProcessRequest(HttpContext context) { 
            HttpResponse response = context.Response; 
            response.Write("Hello From Http Handler"); 
        } 
    } 


The next step is to register the http handler in the web.config,

<httpHandlers> 
   <add verb="*" path="AllUsers/User.gif" type="MyProject.MyHttpHandler,MyProject"/> 
</httpHandlers> 


The above code (point 4) should be added as a child of <system.web>

That's all. Now HTTP Handler is ready

Section2
When using HTTP Handler with either MVC or WEB API, you will get the following error:


Because each MVC and WEB API are using routing to access methods within the controller, they will search the path and find that it is not found. To solve this problem you have two choices:

The first one is,

  • Create a class file --  it could be MyRouteHandler.cs
  • Let MyRouteHandlerclass inherit from IRouteHandlerInterface.
  • In MyRouteHandler class, implement all the methods which are found in IRouteHandlerInterface and return the MyHttpHandlerwhich are created in the previous section.

You should do the following,
public class MyRouteHandler: IRouteHandler { 
    public IHttpHandler GetHttpHandler(RequestContext requestContext) { 
        return new MyHttpHandler(); 
    } 


In RouteConfig class which is related to MVC and WEP API and responsible for requests routing, add the following line code to RegisterRoutes method and before the Default MapRoute.
routes.Add(new Route("AllUsers/User.gif", new MyRouteHandler())); 

Drop the HTTP Handler registration from web.config, since calling HTTP Handler will be from RegisterRoutes method.

The Second Solution Is:

Let us go back to section 1. It is a straightforward solution: In RouteConfig class which is related to MVC and WEP API and responsible for requests routing, add the following line of code to the RegisterRoutes method and before the Default MapRoute.
routes.IgnoreRoute("AllUsers/User.gif"); 

That's it.

Note
If you want to Handle all HTTP requests which have a specific extentaion such as gif you can using the following in web.config.
<httpHandlers> 
   <add verb="*" path="*.gif" type="MyProject.MyHttpHandler,MyProject"/> 
</httpHandlers> 

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ASP.NET Core 2.2.1 Hosting - HostForLIFE.eu :: How to Unloading Assemblies in C#?

clock September 12, 2018 08:06 by author Peter

If you've created an Application Domain and want to unload all the assemblies loaded within, there is no way to unload Assembly themselves. But you can unload Application Domain you've just created.
 
In addition to that one;
You cannot unload the default Application Domain CLR created on its own. And unloading can differ from the assemblies being used and the unload events these assemblies have. It can take some time.
 
To Unload an Application Domain all you need to do is calling Unload function.
 
A sample code can help you understand:
    AppDomain myDom=AppDomain.Create("Ibrahims Domain"); 
    //Here assuming you loaded your assemblies 
    //To unload AppDomain call Unload Function 
    AppDomain.Unload(myDom); 
    // The Application Domain we've just created is now no more as the assemblies with it. 


After Unloading Application Domain object, we've also unloaded all the assemblies loaded within.

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European best, cheap and reliable ASP.NET hosting with instant activation. HostForLIFE.eu is #1 Recommended Windows and ASP.NET hosting in European Continent. With 99.99% Uptime Guaranteed of Relibility, Stability and Performace. HostForLIFE.eu security team is constantly monitoring the entire network for unusual behaviour. We deliver hosting solution including Shared hosting, Cloud hosting, Reseller hosting, Dedicated Servers, and IT as Service for companies of all size.

 



ASP.NET Core 2.2.1 Hosting - HostForLIFE.eu :: How to Cross Domain ASP.NET Web API Calling Using jQuery AJAX ?

clock September 5, 2018 13:11 by author Peter

If we have made a Restful API utilizing the ASP.NET Core 2.2.1 Web API and if your API is in one space and the UI is in an alternate area then you may get problem because of cross-domain issues. And here is the way:

  • OPTIONS http://localhost:5000/api/ 404 (Not Found).XMLHttpRequest cannot load http://localhost:5000/api/.
  • No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http://localhost:54317' is therefore not allowed access. The response had HTTP status code 404.

As it were you can't make a call to the WebAPI by means of your front end that is facilitated on an alternate domain.
So you must utilization JSONP to get information utilizing using AJAX, not by JSON.  To attain to this objective you have to introduce JsonpMediaTypeFormatter. For introducing the JsonpMediaTypeFormatter in Visual Studio, seek JsonpMediaTypeFormatter in "Manage NuGet Packages" and install it.

Next, you can see in your project references that a new DLL was added. WebApiContrib.Formatting.Jsonp.dll

To use this DLL you need to change in the Application_Start() method in the Global.asax.cs file.
using WebApiContrib.Formatting.Jsonp;   
using System.Net.Http.Formatting;   

GlobalConfiguration.Configuration.Formatters.Clear();   GlobalConfiguration.Configuration.Formatters.Add(new JsonpMediaTypeFormatter(new JsonMediaTypeFormatter())); 

You also can use JsonMediaTypeFormatter code, you should write this code in the App_Start folder & register the following code in Application_Start().
JsonMediaTypeFormatter code:
    using System;   
    using System.Collections.Generic;   
    using System.Linq;   
    using System.Web;   
    using System.Net.Http.Formatting;   
    using System.Net.Http.Headers;   
    using System.Net.Http;   
    using Newtonsoft.Json.Converters;   
    using System.IO;   
    using System.Net;   
    using System.Threading.Tasks;   
    namespace WebAPI   
    {   
        /// <summary>   
        /// Handles JsonP requests when requests are fired with text/javascript   
        /// </summary>   
        public class JsonpFormatter : JsonMediaTypeFormatter   
        {   
            public JsonpFormatter()   
            {   
                SupportedMediaTypes.Add(new MediaTypeHeaderValue("application/json"));   
                SupportedMediaTypes.Add(new MediaTypeHeaderValue("text/javascript"));           
                JsonpParameterName = "callback";   
            }   
            /// <summary>   
            ///  Name of the query string parameter to look for   
            ///  the jsonp function name   
            /// </summary>   
           public string JsonpParameterName { get; set; }   
           /// <summary>   
            /// Captured name of the Jsonp function that the JSON call   
            /// is wrapped in. Set in GetPerRequestFormatter Instance   
            /// </summary>   
            private string JsonpCallbackFunction;
            public override bool CanWriteType(Type type)   
            {   
                return true;   
            }           
            /// <summary>   
            /// Override this method to capture the Request object   
            /// </summary>   
            /// <param name="type"></param>   
            /// <param name="request"></param>   
            /// <param name="mediaType"></param>   
            /// <returns></returns>   
            public override MediaTypeFormatter GetPerRequestFormatterInstance(Type type, HttpRequestMessage request, MediaTypeHeaderValue mediaType)   
            {   
                var formatter = new JsonpFormatter()   
                {   
                    JsonpCallbackFunction = GetJsonCallbackFunction(request)   
                };   
               // this doesn't work unfortunately   
                //formatter.SerializerSettings = GlobalConfiguration.Configuration.Formatters.JsonFormatter.SerializerSettings;   
                // You have to reapply any JSON.NET default serializer Customizations here       
                formatter.SerializerSettings.Converters.Add(new StringEnumConverter());   
                formatter.SerializerSettings.Formatting = Newtonsoft.Json.Formatting.Indented;           
                return formatter;   
            }                   
           public override Task WriteToStreamAsync(Type type, object value,   
                                            Stream stream,   
                                            HttpContent content,   
                                            TransportContext transportContext)   
            {   
                if (string.IsNullOrEmpty(JsonpCallbackFunction))   
                    return base.WriteToStreamAsync(type, value, stream, content, transportContext);   
                        StreamWriter writer = null;           
                // write the pre-amble   
                try   
                {   
                    writer = new StreamWriter(stream);   
                    writer.Write(JsonpCallbackFunction + "(");   
                    writer.Flush();   
                }   
                catch (Exception ex)   
                {   
                    try   
                    {   
                        if (writer != null)   
                            writer.Dispose();   
                    }   
                   catch { }           
                    var tcs = new TaskCompletionSource<object>();   
                    tcs.SetException(ex);   
                    return tcs.Task;   
                }           
                return base.WriteToStreamAsync(type, value, stream, content, transportContext)   
                           .ContinueWith(innerTask =>   
                           {   
                               if (innerTask.Status == TaskStatus.RanToCompletion)   
                               {   
                                   writer.Write(")");   
                                   writer.Flush();   
                               }   
                               writer.Dispose();   
                               return innerTask;   
                           }, TaskContinuationOptions.ExecuteSynchronously)   
                                .Unwrap();   
            }   
                    /// <summary>   
            /// Retrieves the Jsonp Callback function   
            /// from the query string   
           /// </summary>   
           /// <returns></returns>   
            private string GetJsonCallbackFunction(HttpRequestMessage request)   
            {   
                if (request.Method != HttpMethod.Get)   
                    return null;   
                        var query = HttpUtility.ParseQueryString(request.RequestUri.Query);   
                var queryVal = query[this.JsonpParameterName];   
                        if (string.IsNullOrEmpty(queryVal))   
                    return null;           
                return queryVal;   
            }   
        }   
    } 

Next step, use the following code to make change in the Application_Start() method in the Global.asax.cs file.
GlobalConfiguration.Configuration.Formatters.Insert(0, new WebAPI.JsonpFormatter());


jQuery code to use the Web API:
    <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>   
    <script language="javascript" type="text/javascript">   
        function GetInformation() {   
            var apiServicePath = "http://localhost:5000/api/";   
            jQuery.ajax({   
                crossDomain: true,  
                dataType: "jsonp",   
                url: apiServicePath + "test/GetInformation",   
                async: false,   
                context: document.body   
            }).done(function (data) {   
                alert("Done");   
            });   
        };   
    </script> 

 

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ASP.NET Core 2.2.1 Hosting - HostForLIFE.eu :: Mapping Similar Objects In ASP.NET Core 2.0

clock August 20, 2018 11:29 by author Peter

This post is about Automapper. As its name suggests, it will do some sort of mapping. Now, the question is, what sort of mapping? Well, this mapping is all about mapping the properties of two objects with each other. If you have worked on MVC, you must have come across the scenario, where the situation demands you to map properties of the model with the properties of ViewModel. Isn't it a common scenario? So, one way to achieve this is to map each and every property manually with a lot of code, which in turn become very tedious when there are many properties of an object. Another major disadvantage of this approach is it's error-prone.

Hence, Automapper came to rescue. Automapper is an object to object mapping which reduces the manual effort of mapping each property of a class with the same properties of another class. So, let’s start by writing some code and see how it works.

Step 1
First step is to add the required dependency. This can be done either by using UI or by using Nuget package console,

Install-Package AutoMapper.Extensions.Microsoft.DependencyInjection 
if you are using console to add dependency, then on successful installation of the package, the below message will be shown,


Step 2
Get ready with classes which are to be mapped. Here in this case, we have one model class and one ViewModel class as shown below,
public class Contact 
    { 
        public string Name { get; set; } 
        public string SecurityNumber { get; set; } 
        public string Address { get; set; } 
    } 


ContactViewModel

public class ContactViewModel 
    { 
        public string Name { get; set; } 
        public string SecurityNumber { get; set; } 
        public string City { get; set; } 
        public string State { get; set; } 
    } 


Step 3
Create a class which will take care of all the mappings as shown below, by inheriting the profile which is defined in Automapper namespace,
public class MappingEntity:Profile 
    { 
        public MappingEntity() 
        { 
            CreateMap<ContactViewModel, Contact>(); 
        } 
    } 


Step 4
Register this MappingEntity class in Startup class under ConfigureServices method as shown below,
public void ConfigureServices(IServiceCollection services) 
        { 
            services.AddMvc(); 
            services.AddAutoMapper(x => x.AddProfile(new MappingEntity())); 
        } 


Step 5
Final step is to do the changes in Controller class to accomodate this mapping.
public class HomeController : Controller 
   { 
       private readonly IMapper _mapper; 
       public HomeController(IMapper mapper) 
       { 
           _mapper = mapper; 
       } 
 
       public IActionResult Index(ContactViewModel vm) 
       { 
           var contact = _mapper.Map<Contact>(vm); 
           return View(); 
       } 
 
    ... 
  } 

Now, as per the business requirement, the contact object declared in line number 11 can be used. That's all about automapping.

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ASP.NET Core 2.2.1 Hosting - HostForLIFE.eu :: Using WebApiClient To Call REST APIs In .NET Core

clock August 15, 2018 11:14 by author Peter

In this article, we will discuss an easy way to call our REST APIs in .NET Core. When we call other APIs in .NET Core, HttpClient will be the first choice. And most of us will create a wrapper to make it easy to use. There are many libraries that are based on HttpClient which help us to call REST APIs.

In this article, I will use WebApiClient.

WebApiClient
WebApiClient is an awesome project which help us to call HTTP(S) APIs. For more information, please visit its GITHUB page,

Here I will use WebApiClient.JIT to demonstrate how to use. Let's begin!

Create Some APIs

Here I use ASP.NET Core WebAPI to creat some RESTful APIs.
    [Route("api/[controller]")] 
    public class PersonsController : Controller 
    { 
        // GET: api/persons 
        [HttpGet] 
        public IEnumerable<Person> Get() 
        { 
            return new List<Person> 
            { 
                new Person{Id = 1 , Name = "stewart"}, 
                new Person{Id = 2 , Name = "peter"} 
            }; 
        } 
     
        // GET api/persons/5 
        [HttpGet("{id}")] 
        public Person Get(int id) 
        { 
            return new Person { Id = id, Name = "name" }; 
        } 
     
        // POST api/persons 
        [HttpPost] 
        public Person Post([FromBody]Person person) 
        { 
            if (person == null) return new Person(); 
     
            return new Person { Id = person.Id, Name = person.Name }; 
        } 
     
        // PUT api/persons/ 
        [HttpPut] 
        public string Put([FromBody]int id) 
        { 
            return $"put {id}"; 
        } 
     
        // DELETE api/persons/5 
        [HttpDelete("{id}")] 
        public string Delete(int id) 
        { 
            return $"del {id}"; 
        } 
    } 


Interface Declaration

Create an interface named IPersonApiClient which inherit from IHttpApiClient.
    public interface IPersonApiClient : IHttpApiClient { } 

Add some methods that need to call APIs.
Every method must have a HTTP attribute that provides the request method and relative URL. The return type should be ITask<T>.
    [HttpGet("/api/persons")]   
    ITask<List<Person>> GetPersonsAsync();   

A request URL can be updated dynamically using replacement blocks and parameters on the method. A replacement block is an alphanumeric string surrounded by { and }.
    [HttpGet("/api/persons/{id}")] 
    ITask<Person> GetPersonAsync(int id); 


When our requst parameters should in request body, we can use some attributes to specify the content, such as JsonContent, FormContent .etc.
    [HttpPost("/api/persons")] 
    ITask<Person> AddPersonAsync([JsonContent]Person person);  


The following code demonstrates the basic usage.
    public interface IPersonApiClient : IHttpApiClient 
    { 
        [HttpGet("/api/persons")] 
        ITask<List<Person>> GetPersonsAsync(); 
     
        [HttpGet("/api/persons/{id}")] 
        ITask<Person> GetPersonAsync(int id); 
     
        [HttpPost("/api/persons")] 
        ITask<Person> AddPersonAsync([JsonContent]Person person); 
     
        [HttpPut("/api/persons")] 
        ITask<string> EditPersonAsync([JsonContent]int id); 
     
        [HttpDelete("/api/persons/{id}")] 
        ITask<string> DeletePersonAsync(int id); 
    } 


The next step is how to retrieve the response of the request.
Retrieving Response

We should create a client first. After creating , what we need to do is call the methods we declared in the interface.

    //specify the config 
    var config = new HttpApiConfig 
    {                 
        HttpHost = new Uri("http://localhost:9999"), 
    }; 
     
    var client = HttpApiClient.Create<IPersonApiClient>(config); 
     
    var persons = await client.GetPersonsAsync(); 
     
    Console.WriteLine("GetPersonsAsync result:"); 
    foreach (var item in persons) 
    { 
        Console.WriteLine($"{item.Id}-{item.Name}"); 
    } 
     
    var person = await client.GetPersonAsync(1000); 
    Console.WriteLine("GetPersonAsync result:"); 
    Console.WriteLine($"{person.Id}-{person.Name}"); 
     
     
    var newPerson = new Person { Id = 999, Name = "999" }; 
    var postResult = await client.AddPersonAsync(newPerson); 
    Console.WriteLine("AddPersonAsync result:"); 
    Console.WriteLine($"{postResult.Id}-{postResult.Name}"); 
     
     
    var editResult = await client.EditPersonAsync(1); 
    Console.WriteLine("EditPersonAsync result:"); 
    Console.WriteLine($"{editResult}"); 
     
    var delResult = await client.DeletePersonAsync(1); 
    Console.WriteLine("DeletePersonAsync result:"); 
    Console.WriteLine($"{delResult}");

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ASP.NET Core 2.2.1 Hosting - HostForLIFE.eu :: How To Create And Download Zipped Files In .NET?

clock August 13, 2018 12:12 by author Peter

Have you ever encountered a scenario when you have to download a few files zipped and compressed? Few developments involving the manipulation of documents and its management would require this. There are a lot of packages out in the market. Here, in this article, I would be sharing the use of DotNetZip package used to zip, unzip & compress files using C#, VB.NET, & any .NET language.

Once downloaded, it's all set to use the DotNetzip package to start zipping the files and compressing them. For the files to be zipped, here I will be using the file path and select each file to be zipped. Here also, we will see how a file is created on the fly (a PDF using Rotativa) is saved in the same folder and zipped.

File created on the fly using Rotativa
var pdfResult = new Rotativa.PartialViewAsPdf("~/Template.cshtml", model) //This is HTML that would be generated as PDF 

    FileName = "Template.pdf" 
}; 
var resultSet = pdfResult.BuildPdf(ControllerContext); 
if (resultSet != null) { 
    string path = Path.Combine(Server.MapPath(subPath)); 
    FileStream fs = new FileStream(path + ".pdf", FileMode.Create, FileAccess.ReadWrite); 
    BinaryWriter bw = new BinaryWriter(fs); 
    bw.Write(resultSet); 
    bw.Close(); 


The above code snippet is generating a PDF using a cshtml Razor View page using Rotativa Using Rotativa Best to follow the mentioned article for more information to generate PDF using Rotativa using MVC. Let's look at the code snippet for zipping.
using(ZipFile zipFile = new ZipFile()) { 
    //Get all filepath from folder 
    String[] files = Directory.GetFiles(Server.MapPath("/")); 
    string fileUniqueName = "Template" 
    foreach(string file in files) { 
        if (file.Contains(fileUniqueName.ToString())) { 
            zipFile.AddFile(file, @ "TemplateDocs_" + DateTime.Now); 
            //Adding files from filepath into Zip 
        } 
    } 
    Response.ClearContent(); 
    Response.ClearHeaders(); 
    //Set zip file name 
    Response.AppendHeader("content-disposition", "attachment; filename=TemplatedDocuments.zip"); 
    zipFile.CompressionMethod = CompressionMethod.BZip2; 
    zipFile.CompressionLevel = Ionic.Zlib.CompressionLevel.BestCompression; 
    //Save the zip content in output stream 
    zipFile.Save(outputStream); 

//Set the cursor to start position 
outputStream.Position = 0; 
String[] filesToDelete = Directory.GetFiles(Server.MapPath("/")); 
foreach(string file in filesToDelete) { 
    if (file.Contains(fileUniqueName.ToString())) { 
        FileInfo fi = new FileInfo(file); 
        fi.Delete(); 
    } 

return new FileStreamResult(outputStream, fileType); 

The above snippet is just required to start zipping and compressing the files. As you can see using block for the ZipFile is created with instantiation of its object.

Then, the files present under the path are navigated using Server.MapPath(""), Once the path is set, the files if with some unique string character in the filename needs to be searched and only zipped, is set to a variable.

Then each file is looped through and added to the ZipFile object, here zipFile.AddFiles(file, ZippedFolderName); ZipFolderName here is the name you set for the folder having all the files after extraction.

There are three compression levels for the ZipFile an enum which describes through code as below,
// 
// Summary: 
// The method of compression to use for a particular ZipEntry. 
// 
// Remarks: 
// http://www.pkware.com/documents/casestudies/APPNOTE.TXT describes a number of 
// distinct cmopression methods that can be used within a zip file. DotNetZip supports 
// a subset of them. 
public enum CompressionMethod { 
    // 
    // Summary: 
    // No compression at all. For COM environments, the value is 0 (zero). 
    None = 0, 
        // 
        // Summary: 
        // DEFLATE compression, as described in http://www.ietf.org/rfc/rfc1951.txt. This 
        // is the "normal" compression used in zip files. For COM environments, the value 
        // is 8. 
        Deflate = 8, 
        // 
        // Summary: 
        // BZip2 compression, a compression algorithm developed by Julian Seward. For COM 
        // environments, the value is 12. 
        BZip2 = 12 


The above are the three algorithms used. I personally have used only BZip2 based on few good reviews. Once compressed and all files inserted into the folder, the zipped folder is ready to be downloaded using the FileStreamResult in MVC action. This is the simple explanation and the code snippet for the Zip file concept. This is simple and really handy to be used and it also provides the compression algorithms which are good to go with.

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ASP.NET Core 2.2.1 Hosting - HostForLIFE.eu :: Deleting Files With Events

clock August 8, 2018 09:12 by author Peter

While working on the dotNetTips Dev Cleaner utility, I wanted to make the deletion of files even faster. While writing this utility I found and worked on speed issues, almost all relating to updating the user interface. So to decouple the deleting from the UI, I decided to add a new feature to the dotNetTips.Utility open source project.

Processor Class
I added a new class in the dotNetTips.Utility.IO namespace called Processor. The purpose of this class is to copy, move and delete files while firing events that can be used to update the UI. Unlike other methods I have used in other frameworks if an exception occurs, it fires an event and keeps processing.

First I created the event,
public event EventHandler<ProgressEventArgs> Processed; 
 
protected virtual void OnProcessed(ProgressEventArgs e) 

EventHandler<ProgressEventArgs> processedEvent = this.ProcessedEvent; 
if (processedEvent != null) 

processedEvent(this, e); 

}  

//The event above is called by the code below: 

public int DeleteFiles(IEnumerable<FileInfo> files) 

    Encapsulation.TryValidateParam(files, "files", ""); 
    int result = 0; 
    IEnumerator<FileInfo> enumerator; 
    try 
    { 
        enumerator = files.AsParallel<FileInfo>().GetEnumerator(); 
        while (enumerator.MoveNext()) 
        { 
            FileInfo current = enumerator.Current; 
            if (current.Exists) 
            { 
                try 
                { 
                    current.Delete(); 
                    result++; 
                    ProgressEventArgs e = new ProgressEventArgs(); 
                    e.Name = current.FullName; 
                    e.ProgressState = ProgressState.Deleted; 
                    e.Size = current.Length; 
                    this.OnProcessed(e); 
                    continue; 
                } 
                catch (Exception ex) 
                { 
                    ProjectData.SetProjectError(ex); 
                    ProgressEventArgs e1 = new ProgressEventArgs(); 
                    e1.Name = current.FullName; 
                    e1.ProgressState = ProgressState.Error; 
                    e1.Size = current.Length; 
                    e1.Message = ex.Message; 
                    this.OnProcessed(e1); 
                    ProjectData.ClearProjectError(); 
                    continue; 
                } 
            } 

            ProgressEventArgs e2 = new ProgressEventArgs(); 
            e2.Name = current.FullName; 
            e2.ProgressState = ProgressState.Error; 
            e2.Size = current.Length; 
            e2.Message = Resources.FileNotFound; 
            this.OnProcessed(e2); 
        } 
    } 
    finally 
    { 
        if (enumerator != null) 
        { 
            enumerator.Dispose(); 
        } 
    } 

    return result; 


This new class helped my utility go from deleting 1K files per second to up to around 2K per second!

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