int a = default(int);

var number = default(int); // 0
var date = default(DateTime); // DateTime.MinValue
var obj = default(object); // null

int a = default; // 0
Guid guid = default; // 00000000-0000-0000-0000-000000000000

 var ages = new[] {18, default, 50};

 var ages = new[] { default };

string s = default;
if(s == default)
{

}

int a = default;
var x = a > 0 ? default : 1.5;

 You can control me by sending these commands :

/ newbot - create a new bot

/ token - generate authorization token

/ revoke - revoke bot access token

/ setname - change a bot's name

/ setdescription - change bot description

/ setabouttext - change bot about info

/ setuserpic - change bot profile photo

/ setcommands - change bot commands list

/ setjoingroups - can your bot be added to groups ?

/ setprivacy - what messages does your bot see in groups ?

/ deletebot - delete a bot

/ cancel - cancel the current operation

public class mydata
    {
        public result[] result;
    }
    public class result
    {
        public int update_id { get; set; }
        public message message { get; set; }
    }
    public class message
    {
        public int message_id { get; set; }
        public message_from from { get; set; }
        public message_chat chat { get; set; }
        public int date { get; set; }
        public string text { get; set; }
    }
    public class message_from
    {
        public int ind { get; set; }
        public string first_name { get; set; }
        public string username { get; set; }
    }
    public class message_chat
    {
        public int id { get; set; }
        public string first_name { get; set; }
        public string username { get; set; }
    }
 
public  Void GetUpdates()
        {
 
            WebRequest req = WebRequest.Create("https://api.telegram.org/bot" + yourToken + "/getUpdates");
            req.UseDefaultCredentials = true;
            WebResponse resp = req.GetResponse();
            Stream stream = resp.GetResponseStream();
            StreamReader sr = new StreamReader(stream);
            string s = sr.ReadToEnd();
            sr.Close();
            var jobject = Newtonsoft.Json.Linq.JObject.Parse(s);
            mydata gg = JsonConvert.DeserializeObject<mydata>(jobject.ToString());
            List<result> results = new List<result>();
            foreach (result rs in gg.result)
            {
                results.Add(rs); 
                SendMessage(rs.message.chat.id.ToString(), "hello"+" "+"Dear"+rs.message.chat.first_name); 
            }             
        }

public static void SendMessage(string chat_id, string message)
        {
            WebRequest req = WebRequest.Create("https://api.telegram.org/bot" + youToken + "/sendMessage?chat_id=" + chat_id + "&text=" + message);
            req.UseDefaultCredentials = true;
 
            var result = req.GetResponse();
            req.Abort();
        }

[ServiceContract]
public interface IBookService
    {
        [OperationContract]
        int GetCountOfBook();
    }

 [ServiceBehavior(IncludeExceptionDetailInFaults = true)]
    public class BookService : IBookService
    {
        public int GetCountOfBook()
        {
            return 10;
        }
    }

 class Program
    {
        static void Main(string[] args)
        {
            ServiceHost host = new ServiceHost(typeof(BookService));

            var binding = new BasicHttpBinding();
            
            host.AddServiceEndpoint(typeof(IBookService), binding, "http://localhost/BookService");
            host.Open();

            Console.Write("BookService host");

            Console.ReadKey();
        }
    }

        static void Main(string[] args)
        {
            Thread.Sleep(2000);
            BasicHttpBinding binding = new BasicHttpBinding();

            ChannelFactory<IBookService> channel = new ChannelFactory<IBookService>(binding, new EndpointAddress("http://localhost/BookService"));

            Console.WriteLine("Count of book: {0}", channel.CreateChannel().GetCountOfBook());

            Console.ReadKey();
        }

تا اینجا هیچ گونه اعتبار سنجی انجام نشد. برای پیاده سازی اعتبار سنجی باید یک سری تنظیمات بر روی Binding و Hosting  سمت سرور و البته کلاینت بر قرار شود. فایل Program پروزه Service را باز نمایید و محتویات آن را به صورت زیر تغییر دهید:

 static void Main(string[] args)
        {
            ServiceHost host = new ServiceHost(typeof(BookService));

            var binding = new BasicHttpBinding();
            binding.Security = new BasicHttpSecurity();
            binding.Security.Mode = BasicHttpSecurityMode.TransportCredentialOnly;
            binding.Security.Transport.ClientCredentialType = HttpClientCredentialType.Basic;

            host.Credentials.UserNameAuthentication.UserNamePasswordValidationMode = System.ServiceModel.Security.UserNamePasswordValidationMode.Custom;

            host.Credentials.UserNameAuthentication.CustomUserNamePasswordValidator = new CustomUserNamePasswordValidator();               

            host.AddServiceEndpoint(typeof(IBookService), binding, "http://localhost/BookService");
            host.Open();


            Console.Write("BookService host");

            Console.ReadKey();
        }

 public class CustomUserNamePasswordValidator : UserNamePasswordValidator
    {
        public override void Validate(string userName, string password)
        {
            if (userName != "Masoud" || password != "Pakdel")
                throw new SecurityException("Incorrect userName or password");
        }
    }

این خطا از آن جا ناشی می‌شود که تنظیمات کلاینت و سرور از نظر امنیتی با هم تناسب ندارد. در نتیجه باید تنظیمات Binding کلاینت و سرور یکی شود. برای این کار کد زیر را به فایل Program سمت کلاینت اضافه می‌کنیم:

static void Main(string[] args)
        {
            Thread.Sleep(2000);
            BasicHttpBinding binding = new BasicHttpBinding();

            binding.Security = new BasicHttpSecurity();
            binding.Security.Mode = BasicHttpSecurityMode.TransportCredentialOnly;
            binding.Security.Transport.ClientCredentialType = HttpClientCredentialType.Basic;            

            ChannelFactory<IBookService> channel = new ChannelFactory<IBookService>(binding, new EndpointAddress("http://localhost/BookService"));

            channel.Credentials.UserName.UserName = "WrongUserName";
            channel.Credentials.UserName.Password = "WrongPassword";
 



           Console.WriteLine("Count of book: {0}", channel.CreateChannel().GetCountOfBook());

            Console.ReadKey();
        }

channel.Credentials.UserName.UserName = "WrongUserName";
channel.Credentials.UserName.Password = "WrongPassword";

public static string GetSignalRContent()
{
    var resolver = new DefaultHubManager(new DefaultDependencyResolver());
    var proxy = new DefaultJavaScriptProxyGenerator(resolver, new NullJavaScriptMinifier());
    return proxy.GenerateProxy("/signalr");
}

public class CustomVirtualPathProvider : VirtualPathProvider
{
    public CustomActionVirtualPathProvider(VirtualPathProvider virtualPathProvider)
    {
        // Wrap an existing virtual path provider
        VirtualPathProvider = virtualPathProvider;
    }

    protected VirtualPathProvider VirtualPathProvider { get; set; }

    public override string CombineVirtualPaths(string basePath, string relativePath)
    {
        return VirtualPathProvider.CombineVirtualPaths(basePath, relativePath);
    }

    public override bool DirectoryExists(string virtualDir)
    {
        return VirtualPathProvider.DirectoryExists(virtualDir);
    }

    public override bool FileExists(string virtualPath)
    {
        if (virtualPath == "~/signalr/hubs")
        {
            return true;
        }

        return VirtualPathProvider.FileExists(virtualPath);
    }

    public override CacheDependency GetCacheDependency(string virtualPath, IEnumerable virtualPathDependencies, DateTime utcStart)
    {
        // BaseClass can't create a CacheDependency for your content, remove it
        // You could also add your own CacheDependency and aggregate it with the base dependency
        List<string> virtualPathDependenciesCopy = virtualPathDependencies.Cast<string>().ToList();
        virtualPathDependenciesCopy.Remove("~/signalr/hubs");

        return VirtualPathProvider.GetCacheDependency(virtualPath, virtualPathDependenciesCopy, utcStart);
    }

    public override string GetCacheKey(string virtualPath)
    {
        return VirtualPathProvider.GetCacheKey(virtualPath);
    }

    public override VirtualDirectory GetDirectory(string virtualDir)
    {
        return VirtualPathProvider.GetDirectory(virtualDir);
    }

    public override VirtualFile GetFile(string virtualPath)
    {
        if (virtualPath == "~/signalr/hubs")
        {
            return new CustomVirtualFile(virtualPath,
                new MemoryStream(Encoding.Default.GetBytes(GetSignalRContent())));
        }

        return VirtualPathProvider.GetFile(virtualPath);
    }

    public override string GetFileHash(string virtualPath, IEnumerable virtualPathDependencies)
    {
        return VirtualPathProvider.GetFileHash(virtualPath, virtualPathDependencies);
    }

    public override object InitializeLifetimeService()
    {
        return VirtualPathProvider.InitializeLifetimeService();
    }
}

public class CustomVirtualFile : VirtualFile
{
    public CustomVirtualFile (string virtualPath, Stream stream)
        : base(virtualPath)
    {
        Stream = stream;
    }

    public Stream Stream { get; private set; }

    public override Stream Open()
    {
         return Stream;
    }
}

    public override bool FileExists(string virtualPath)
    {
        if (virtualPath == "~/signalr/hubs")
        {
            return true;
        }

        return VirtualPathProvider.FileExists(virtualPath);
    }

    public override CacheDependency GetCacheDependency(string virtualPath, IEnumerable virtualPathDependencies, DateTime utcStart)
    {
        List<string> virtualPathDependenciesCopy = virtualPathDependencies.Cast<string>().ToList();
        virtualPathDependenciesCopy.Remove("~/signalr/hubs");

        return VirtualPathProvider.GetCacheDependency(virtualPath, virtualPathDependenciesCopy, utcStart);
    }

    public override VirtualFile GetFile(string virtualPath)
    {
        if (virtualPath == "~/signalr/hubs")
        {
            return new CustomVirtualFile(virtualPath,
                new MemoryStream(Encoding.Default.GetBytes(GetSignalRContent())));
        }

        return VirtualPathProvider.GetFile(virtualPath);
    }

public static void RegisterBundles(BundleCollection bundles)
{
    BundleTable.VirtualPathProvider =
        new CustomVirtualPathProvider(BundleTable.VirtualPathProvider);

    Bundle include = new Bundle("~/bundle")
        .Include("~/Content/static.js")
        .Include("~/signalr/hubs");

    bundles.Add(include);
}
 

    [Flags]
public enum MiniDumpType
{
    MiniDumpNormal = 0x00000000,
    MiniDumpWithDataSegs = 0x00000001,
    MiniDumpWithFullMemory = 0x00000002,
    MiniDumpWithHandleData = 0x00000004,
    MiniDumpFilterMemory = 0x00000008,
    MiniDumpScanMemory = 0x00000010,
    MiniDumpWithUnloadedModules = 0x00000020,
    MiniDumpWithIndirectlyReferencedMemory = 0x00000040,
    MiniDumpFilterModulePaths = 0x00000080,
    MiniDumpWithProcessThreadData = 0x00000100,
    MiniDumpWithPrivateReadWriteMemory = 0x00000200,
    MiniDumpWithoutOptionalData = 0x00000400,
    MiniDumpWithFullMemoryInfo = 0x00000800,
    MiniDumpWithThreadInfo = 0x00001000,
    MiniDumpWithCodeSegs = 0x00002000,
    MiniDumpWithoutManagedState = 0x00004000
}

public static class NativeMethods
{
    [DllImport("Dbghelp.dll")]
    public static extern bool MiniDumpWriteDump(
        IntPtr hProcess,
        int processId,
        IntPtr hFile,
        MiniDumpType dumpType,
        IntPtr exceptionParam,
        IntPtr userStreamParam,
        IntPtr callbackParam);
}

public static class DebugInfo
{
    public static void CreateMiniDump(
        string dumpFileName, MiniDumpType dumpType = MiniDumpType.MiniDumpNormal)
    {
        using (var stream = File.Create(dumpFileName))
        {
            var process = Process.GetCurrentProcess();
            // It is safe to call DangerousGetHandle() here because the process is already crashing.
            NativeMethods.MiniDumpWriteDump(
                            process.Handle,
                            process.Id,
                            stream.SafeFileHandle.DangerousGetHandle(),
                            dumpType,
                            IntPtr.Zero,
                            IntPtr.Zero,
                            IntPtr.Zero);
        }
    }
 
    public static void CreateMiniDump(MiniDumpType dumpType = MiniDumpType.MiniDumpNormal)
    {
        const string dateFormat = "yyyy-MM-dd-HH-mm-ss-fffZ"; // Example: 2010-09-02-09-50-43-341Z
        var thisAssembly = Assembly.GetEntryAssembly() ?? Assembly.GetCallingAssembly();
        var dumpFileName = string.Format(@"{0}-MiniDump-{1}.dmp",
                    thisAssembly.GetName().Name,
                    DateTime.UtcNow.ToString(dateFormat, CultureInfo.InvariantCulture));
 
        var path = Path.Combine(getApplicationPath(), dumpFileName);
        CreateMiniDump(path, dumpType);
    }
 
    private static string getApplicationPath()
    {
        return HttpContext.Current != null ?
            HttpRuntime.AppDomainAppPath :
            Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location);
    }
}

class Program
{
    static void Main(string[] args)
    {
        try
        {
            var zero = 0;
            Console.WriteLine(1 / zero);
        }
        catch (Exception ex)
        {
            Console.Write(ex);
            DebugInfo.CreateMiniDump(dumpType:
                                MiniDumpType.MiniDumpNormal |
                                MiniDumpType.MiniDumpWithPrivateReadWriteMemory |
                                MiniDumpType.MiniDumpWithDataSegs |
                                MiniDumpType.MiniDumpWithHandleData |
                                MiniDumpType.MiniDumpWithFullMemoryInfo |
                                MiniDumpType.MiniDumpWithThreadInfo |
                                MiniDumpType.MiniDumpWithUnloadedModules);
 
            throw;
        }
    }
}

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Web.Mvc;

namespace SecurityModule
{
    public class AllowUploadSpecialFilesOnlyAttribute : ActionFilterAttribute
    {
        readonly List<string> _toFilter = new List<string>();
        readonly string _extensionsWhiteList;
        public AllowUploadSpecialFilesOnlyAttribute(string extensionsWhiteList)
        {
            if (string.IsNullOrWhiteSpace(extensionsWhiteList))
                throw new ArgumentNullException("extensionsWhiteList");

            _extensionsWhiteList = extensionsWhiteList;
            var extensions = extensionsWhiteList.Split(',');
            foreach (var ext in extensions.Where(ext => !string.IsNullOrWhiteSpace(ext)))
            {
                _toFilter.Add(ext.ToLowerInvariant().Trim());
            }
        }

        bool canUpload(string fileName)
        {
            if (string.IsNullOrWhiteSpace(fileName)) return false;

            var ext = Path.GetExtension(fileName.ToLowerInvariant());
            return _toFilter.Contains(ext);
        }

        public override void OnActionExecuting(ActionExecutingContext filterContext)
        {
            var files = filterContext.HttpContext.Request.Files;
            foreach (string file in files)
            {
                var postedFile = files[file];
                if (postedFile == null || postedFile.ContentLength == 0) continue;

                if (!canUpload(postedFile.FileName))
                    throw new InvalidOperationException(
                        string.Format("You are not allowed to upload {0} file. Please upload only these files: {1}.",
                                        Path.GetFileName(postedFile.FileName), 
                                        _extensionsWhiteList));
            }

            base.OnActionExecuting(filterContext);
        }
    }
}

[AllowUploadSpecialFilesOnly(".jpg,.gif,.png")]
public ActionResult ImageUpload(HttpPostedFileBase file)

public static bool IsImageFile(HttpPostedFileBase photoFile)
{
    using (var img = Image.FromStream(photoFile.InputStream))
    {
         return img.Width > 0;
    }
}