In this article I will sharing few tips to improve the performance in ASP.NET site. This is the things that I have done:

1. HTTP Compression

HTTP compression is used to compress page content from the server end. It compress HTTP requests and responses, so is a great performance improvement. My project is hosted in Windows Server 2003, and I implemented HTTP compression after reading this article.

2. Disable Possible ViewState

View State allows the page state to be persisted with the client, and it does not require cookies or server memory. View State saves data in a hidden input filed inside a page. Definitely, it is a powerful feature, but the drawback is it increases page size and memory allocation in the server.

So, we should avoid View State where it is not necessary. Especially, in the case of DataGrid controls, we should avoid View State as it loads all the grid data in the page state.

In my application, I disabled View State for most of the controls and pages where View State is not necessary. This made the page sizes smaller. 

3. Changes in the Web.Config File

a. Use page caching:

This will save your page only for a certain amount of time, and the page will be faster to load. But, remember that if your page data changes frequently, it is not a good idea to use page caching.

<caching>
<outputCacheSettings>
    <outputCacheProfiles>
        <add name="cached" duration="600"
            varyByParam="none" enabled="true"/>
    </outputCacheProfiles>
</outputCacheSettings>
</caching>

b.Remove unnecessary httpModules from the web.config:

<add name="ScriptModule"
     type="System.Web.Handlers.ScriptModule, System.Web.Extensions,
           Version=3.5.0.0, Culture=neutral,
           PublicKeyToken=31BF3856AD364E35"/>
<remove name="WindowsAuthentication" />
<remove name="PassportAuthentication" />
<remove name="AnonymousIdentification" />
<remove name="UrlAuthorization" />
<remove name="FileAuthorization" />

c.Turn off trace:

<trace enabled="false" pageOutput="false" />

d.As I have used membership, I disabled automatic save for profiles:

<profile enabled="true" automaticSaveEnabled="false" />

e.Set debug=false:

<compilation debug="false">

4. Optimize Stylesheets

It is important to clean up style sheets and remove unnecessary code from style sheets because it increases the load time. Remove all unnecessary classes from style sheets and try to use a single CSS file.

5. Optimize JavaScript

6. JS and CSS File Position

According to the advice from some good articles, I put the CSS file declaration at the top of my master page. It is recommended to call CSS files at the top of a page because the page rendering will progressively become efficient.

I put JavaScript file links at the bottom of the main master file. If we put scripts at the top of the page, then it will cause unnecessarily high load times.

7. Client-side Script for Validation

For page validation, I use client-side validations instead of postbacks. This way, I reduce round trips in pages.

The above are few trips to improve your ASP.NET performance.

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Facebook is one of the top rated social media networking sites that impress everyone. More than 270 million users are using Facebook. 

Facebook connect -- this enables users to integrate Facebook platform to your website. This allow a user to connect with your site using the Facebook account and can share posts on your pages with friends on Facebook. The connection is established between Facebook and your website using a trusted authentication.

Before integrating Facebook on your website, you need to follow these steps:

Setting Up with Facebook

You’ll need to set up your application with Facebook. Set-up is free and happens pretty much instantaneously, because there’s no application approval process to go through.

1. Register your website with Facebook.

Log in to Facebook and visit the developer’s application at Facebook.com/developers. Here you can set up new applications and edit existing ones. You can also access SDK documentation and interact with the Facebook developer community.

In App Name: give the name of your site and continue. It will give you the Unique App ID/App Secret.

The URL of your website and the website URL you registered with Facebook should be same.

Note: If you want to access some additional information like Email ID etc, you have to use OAUTH (which is authorize the user and provide grant permissions to access).

2. Add Facebook DLL Refrences to your website/bin folder

- Facebook.dll  
- Facebook.web.dll

3. Web.config 

 Add the App ID/App Secret  value 

 <appSettings>
    <add key="redirect_uri" value="<your_redirect_uri>">
    <add key="AppKey" value="<your_App_ID>"/>
    <add key="AppSecret" value="<your_App_Secret>"/>
 </appSettings>

4. Add Facebook login button in your login.aspx page

<asp:Panel ID="pnlLogin" runat="server">
                    <a href="https://www.facebook.com/dialog/oauth?client_id=your_app_id&redirect_uri=your_redirect_uri">
                        <img src="../../images/f_login.png"  />
                    </a>
 </asp:Panel>
<a id="lbllogout" runat="server" onserverclick="lbllogout_Click" visible="false" > </a>

 For accessing some additional information like offline_access,email etc, you have to add scope feature in login like

<a href="https://www.facebook.com/dialog/oauth?client_id=your_app_id&redirect_uri=your_redirect_uri&scope=offline_access,user_status,publish_stream,email,manage_pages,user_groups">

It will ask you for allowing the permissions. Click Allow.

5. Now add code in login.aspx.cs to access Facebook user details in your page

using Facebook.Web;
using Facebook;

string getAccessToken = "";
WebClient client = new WebClient();

 protected void Page_Load(object sender, EventArgs e)
  {
           string fbCodeGiven = Request.QueryString["code"];
            if ((fbCodeGiven != null))
            {
                WebRequest AccessTokenWebRequest = WebRequest.Create("https://graph.facebook.com
                 /oauth/access_token?client_id=" + your_App_ID + "&redirect_uri=" +
                 your_redirect_uri  +  "&client_secret=" + your_App_Secret"] + "&code=" +
                 fbCodeGiven);

                StreamReader AccessTokenWebRequestStream = new
                StreamReader(AccessTokenWebRequest.GetResponse().GetResponseStream());
                string WebRequestResponse = AccessTokenWebRequestStream.ReadToEnd();
                getAccessToken = WebRequestResponse.Substring(13, WebRequestResponse.Length -
                                                13);

                Session["getAccessToken"] = getAccessToken;
                string url, userInformation, email = null, CorrectEmail = null, id = null,
                first_name = null, last_name = null;

                Regex getValues;
                Match infoMatch;
                string username = "me";
                url = "https://graph.facebook.com/" + username + "/" + "?access_token=" +
                          getAccessToken;

                userInformation = client.DownloadString(url);
                getValues = new Regex("(?<=\"email\":\")(.+?)(?=\")");
                infoMatch = getValues.Match(userInformation);
                email = infoMatch.Value;
                CorrectEmail = email.Replace("\\u0040", "@");

                getValues = new Regex("(?<=\"id\":\")(.+?)(?=\")");
                infoMatch = getValues.Match(userInformation);
                id = infoMatch.Value;
                Session["facebookuserID"] = id;

                getValues = new Regex("(?<=\"first_name\":\")(.+?)(?=\")");
                infoMatch = getValues.Match(userInformation);
                first_name = infoMatch.Value;

                getValues = new Regex("(?<=\"last_name\":\")(.+?)(?=\")");
                infoMatch = getValues.Match(userInformation);
                last_name = infoMatch.Value;
            }
}

protected void lbllogout_Click(object sender, EventArgs e)
{
            if (Convert.ToString(Session["facebookuserID"]) != "")
            {
                string getAccessToken = Convert.ToString(Session["getAccessToken"]);
                Session.Remove("facebookuserID");
                Response.Redirect("https://www.facebook.com/logout.php?next=" + your_redirect_uri
                                                 + "&access_token=" + getAccessToken);
                Session.Remove("getAccessToken");
            }
 }

The URL supplied in the next parameter must be a URL with the same base domain as your application as defined in your app's settings.

IMPORTANT NOTE -- You must replace "your_App_ID", "your_App_Secret" with the APP ID, APP Secret you find in your application details in the Developer application on Facebook!

Then, run your application/site. Hope this tutorial help.

Often when working with web applications it is necessary to secure access to documents or other user supplied resources.  If you look online you will find a number of different recommendations on how to accomplish this.  Some will recommend a HTTP Handler, some will recommend a simple ASPX, others will have other random ideas.  Regardless of the actual implementation there is always a common area of mixed recommendation, once you have validated that the user has the proper permissions to access the resource, how do you get the item to the user?  In this post I'll discuss a new API that is publicly available in .NET 4.5 that helps with one problem area.

The Problem

Determining if the user has access to the resource in question is rarely the area that causes trouble.  The problem comes with the process of serving the desired files to the user.  When you let IIS handle the serving of a file it automatically sets the Content Type on the HTTP Response to match the proper type for the file, however, if you are sitting in the middle of this process, you have to handle this yourself.

Recommendation to Solve Issue

If you look into this issue, try googleing "Determining File MIME Types" or similar.  You will find all kinds of recommendations.  They will range from creating a custom look up process based on file extension, to weird PInvoke calls into windows, or even from the really crafty individuals a reflection call to an internal member of previous versions of the .NET framework.

In the end, there has never really been a good, consistent way to handle this.  Often times if you are working with a limited subset of file types the switch statement solution will work, however, as new file types are added etc it becomes harder to manage.

New Solution

With .NET 4.5, there is a newly exposed class that can be used to solve this complicated process.  System.Web.MimeMapping is a class that has existed for a while prior to .NET 4.5 but was "internal" to the framework and could not easily be called without using reflection.  Now you can simply call a method with a file path and it will return the Content Type.

This makes it so that we can now use something as simple as the following to serve a secured document after validating that the user has permissions.

Response.Clear();
Response.ContentType =
  System.Web.MimeMapping.GetMimeMapping(Server.MapPath(document.ServerDocumentPath));
Response.AddHeader("Content-Disposition",
                    "attachment; filename=" + document.UploadedDocumentName);
Response.WriteFile(Server.MapPath(document.ServerDocumentPath));
Response.End();

As you can see here, it is just 5 lines of code. In the first line of code we clear anything that  might have already been written to the response.  In the second line we call out to MimeMapping's GetMimeMapping method providing it the filepath to our document.  The third line we are telling the browser that we want to force download the file and are specifying a custom file name.  Then in the last two lines we write the file to the response and end.

The nice thing with this approach as you can see in the above example we can have a different ServerDocumentPath than our actual document name.  This allows us to hide the files in a different manner and serve them up to users with a friendly name.

I hope this helps someone looking for a way to introduce a security process to file downloads.  This .NET framework MimeType mapping is very helpful for this type of situation.

In this article I try to explain the default submit behavior of form and panel. Suppose, you want to press/click submit button on Enter key press or you are trying to post the form on Enter key press. In asp.net, to achieve this functionality we need to set "Defaultbutton" property either in Form or in panel.

Form DefaultButton Property

     <form id="form1" runat="server" defaultbutton="btnSubmit">
    <div>
    <asp:TextBox ID="txtUserID" runat="server"/> <asp:TextBox ID="txtUserpwd" runat="server"/> <asp:Button ID="btnSubmit" runat="server" OnClick="btnSubmit _Click" Text="Submit"/>
    </div>
    </form>

Panel DefaultButton Property

     <asp:Panel ID="Panel1" runat="server" defaultbutton="btnSubmit">
    <div>
    <asp:TextBox ID="txtUserID" runat="server"/> <asp:TextBox ID="txtUserpwd" runat="server"/> <asp:Button ID="btnSubmit" runat="server" OnClick="btnSubmit _Click" Text="Submit"/>
    </div>
    </asp:Panel >

Note

1. We specify the defaultbutton property at the Form level in the form tag when there is only one Submit Button for post back.

2. We specify the defaultbutton property at the Panel level in the Panel tag when there are multiple Submit Button for post back.

In this article we will learn how to enable Unobtrusive Validation in ASP.NET 4.5.

Visual Studio 2012 provides some new Validation features that include Unobtrusive Validation. When you work with this Validation mode you will find that there is not much difference in this validation and previous validations but to enable this type of validation you had to first configure your Web Application.

There are three ways to enable the Unobtrusive Validation in your Web Application; they are:

- By using Web.Config file
- By using Global.asax file
- By using Page_Load event on each page

The first method is by using the Web.Config file.

Step 1

Write the following code in your Web.Config file:

<configuration>
  <appSettings>
    <add key="ValidationSettings:UnobtrusiveValidationMode" value="None"></add>
  </appSettings>
    <system.web>
      <compilation debug="true" targetFramework="4.5" />
      <httpRuntime targetFramework="4.5" />
    </system.web> 
</configuration>

Step 2

Now write the following code in your WebForm.aspx Page:

<asp:TextBox runat="server" ID="txt" />
     <asp:RequiredFieldValidator ID="RequiredFieldValidator1" ErrorMessage="txt is required"ControlToValidate="txt" runat="server" Text="Text is Required" Display="Dynamic" />

    <asp:Button ID="Button1" Text="Send info" runat="server" />

Step 3

Now debug your code, on debugging the code you will get the output like this:

When you click on the button in the output window you will see an Error Message. As you write in the Text Box and click again on the Button the error message will be disposed of automatically.

The second method is by using a Global.asax file.

Step 1

In the Global.asax file, first add the namespace "using System.Web.UI;".

After adding the namespace write the following code in the Application_Start method:

protected void Application_Start(object sender, EventArgs e)
{
    ValidationSettings.UnobtrusiveValidationMode = UnobtrusiveValidationMode.None;
}

Step 2

Now write the following code in your WebForm.aspx page:

<asp:TextBox runat="server" ID="txt" />
     <asp:RequiredFieldValidator ID="RequiredFieldValidator1" ErrorMessage="txt is required"ControlToValidate="txt" runat="server" Text="Text is Required" Display="Dynamic" />

    <asp:Button ID="Button1" Text="Send info" runat="server" />

Step 3

Again debugging your Web Application you will again get the same output as you got in the first method.

The third method is by simply writing the code on each page inside the Page_Load event.

Step 1

protected void Page_Load(object sender, EventArgs e)
{
    this.UnobtrusiveValidationMode = System.Web.UI.UnobtrusiveValidationMode.None;

}

Step 2

Now write the following code in your WebForm.aspx page:

<asp:TextBox runat="server" ID="txt" />
     <asp:RequiredFieldValidator ID="RequiredFieldValidator1" ErrorMessage="txt is required"ControlToValidate="txt" runat="server" Text="Text is Required" Display="Dynamic" />

    <asp:Button ID="Button1" Text="Send info" runat="server" />

Step 3

Again debug your Web Application and you will again get the same output as you got in the first method.

This is brief tutorial how to download file from FTP using C#/VB.NET. Let’s start it:

C#

using System.Net;
using System.IO;

VB.NET

Imports System.Net
Imports System.IO

Following is the code of download file from the FTP Server.

C#

private void Download(string filePath, string fileName)
   {
       FTPSettings.IP = "DOMAIN NAME";
       FTPSettings.UserID = "USER ID";
       FTPSettings.Password = "PASSWORD";
       FtpWebRequest reqFTP = null;
       Stream ftpStream = null;
       try
       {
           FileStream outputStream = new FileStream(filePath + "\\" + fileName, FileMode.Create);
           reqFTP = (FtpWebRequest)FtpWebRequest.Create(new Uri("ftp://" + FTPSettings.IP + "/" + fileName));
           reqFTP.Method = WebRequestMethods.Ftp.DownloadFile;
           reqFTP.UseBinary = true;
           reqFTP.Credentials = new NetworkCredential(FTPSettings.UserID, FTPSettings.Password);
           FtpWebResponse response = (FtpWebResponse)reqFTP.GetResponse();
           ftpStream = response.GetResponseStream();
           long cl = response.ContentLength;
           int bufferSize = 2048;
           int readCount;
           byte[] buffer = new byte[bufferSize];

           readCount = ftpStream.Read(buffer, 0, bufferSize);
           while (readCount > 0)
           {
               outputStream.Write(buffer, 0, readCount);
               readCount = ftpStream.Read(buffer, 0, bufferSize);
           }

           ftpStream.Close();
           outputStream.Close();
           response.Close();
       }
       catch (Exception ex)
       {
           if (ftpStream != null)
           {
               ftpStream.Close();
               ftpStream.Dispose();
           }
           throw new Exception(ex.Message.ToString());
       }
   }
   public static class FTPSettings
   {
       public static string IP { get; set; }
       public static string UserID { get; set; }
       public static string Password { get; set; }
   }

VB.NET

   Private Sub Download(ByVal filePath As String, ByVal fileName As String)
       FTPSettings.IP = "DOMAIN NAME"
       FTPSettings.UserID = "USER ID"
       FTPSettings.Password = "PASSWORD"
       Dim reqFTP As FtpWebRequest = Nothing
       Dim ftpStream As Stream = Nothing
       Try
           Dim outputStream As New FileStream(filePath + "\" + fileName, FileMode.Create)
           reqFTP = DirectCast(FtpWebRequest.Create(New Uri("ftp://" + FTPSettings.IP + "/" + fileName)), FtpWebRequest)
           reqFTP.Method = WebRequestMethods.Ftp.DownloadFile
           reqFTP.UseBinary = True
           reqFTP.Credentials = New NetworkCredential(FTPSettings.UserID, FTPSettings.Password)
           Dim response As FtpWebResponse = DirectCast(reqFTP.GetResponse(), FtpWebResponse)
           ftpStream = response.GetResponseStream()
           Dim cl As Long = response.ContentLength
           Dim bufferSize As Integer = 2048
           Dim readCount As Integer
           Dim buffer As Byte() = New Byte(bufferSize - 1) {}

           readCount = ftpStream.Read(buffer, 0, bufferSize)
           While readCount > 0
               outputStream.Write(buffer, 0, readCount)
               readCount = ftpStream.Read(buffer, 0, bufferSize)
           End While

           ftpStream.Close()
           outputStream.Close()
           response.Close()
       Catch ex As Exception
           If ftpStream IsNot Nothing Then
               ftpStream.Close()
               ftpStream.Dispose()
           End If
           Throw New Exception(ex.Message.ToString())
       End Try
   End Sub
   Public NotInheritable Class FTPSettings
       Private Sub New()
       End Sub
       Public Shared Property IP() As String
           Get
               Return m_IP
           End Get
           Set(ByVal value As String)
               m_IP = Value
           End Set
       End Property
       Private Shared m_IP As String
       Public Shared Property UserID() As String
           Get
               Return m_UserID
           End Get
           Set(ByVal value As String)
               m_UserID = Value
           End Set
       End Property
       Private Shared m_UserID As String
       Public Shared Property Password() As String
           Get
               Return m_Password
           End Get
           Set(ByVal value As String)
               m_Password = Value
           End Set
       End Property
       Private Shared m_Password As String
   End Class

Hope you enjoy this simple tutorial. :)

Lots of people are excited about the new bundling and minification feature in the next version of ASP.NET and MVC. One major drawback I see a lot of people clamoring about is the fact that you cannot conditionally disable bundling or minification when you are in debug mode. Out of the box (and to be clear, I’m referring to the version that ships with MVC 4 beta) it’s impossible to debug your CSS and Javascript.

I expect this will change in the release version, but for now you are forced to create your own custom bundles (something you’d end up doing anyway) and conditionally check if you’re in debug mode to short-circuit the bundling/minification.

Disabling minification while in debug mode

It’s as simple as an #if DEBUG line and creating a transformer that does nothing. For example:

01           protected void Application_Start()
02           {
03               IBundleTransform jsTransformer;
04           #if DEBUG
05               jsTransformer = new NoTransform("text/javascript");
06           #else
07               jstransformer = new JsMinify();
08           #endif
09          
10               var bundle = new Bundle("~/Scripts/js", jsTransformer);
11          
12               bundle.AddFile("~/Scripts/script1.js");
13               bundle.AddFile("~/scripts/script2.js");
14          
15               BundleTable.Bundles.Add(bundle);
16           }

Now when you reference this javascript bundle like <script src="@System.Web.Optimization.BundleTable.Bundles.ResolveBundleUrl("~/Scripts/js")"></script> in a view it will render a single bundled and minified script when in release mode, but as a single bundled, non-minified file while in debug mode.

Disabling bundling while in debug mode

The above approach improves this situation, but I don’t think it goes far enough. If I’m going to have multiple source files, I want to debug with the same multiple source files, at least initially. It would get too confusing writing code in a several files and then debugging it in a single monolithic file.

As an experiment to see if it was possible, I ended up building a better bundler that does just what I want: bundles and minifies in release mode, but doesn’t bundle or minify when the build is set to debug.

The entire class is below, explanation to follow:

01           public static class BetterBundler
02           {
03               private static bool _debug;
04               const string CssTemplate = "<link href=\"{0}\" rel=\"stylesheet\" type=\"text/css\" />";
05          
06               public static void Init()
07               {
08           #if DEBUG
09                   _debug = true;
10           #endif
11                   var bundle = new Bundle("~/content/css", new CssMinify());
12          
13                   bundle.AddFile("~/Content/test.css");
14                   bundle.AddFile("~/Content/site.css");
15                   
16                   BundleTable.Bundles.Add(bundle);
17               }
18          
19               public static MvcHtmlString ResolveBundleUrl(string bundleUrl)
20               {
21                   return _debug ? BundledFiles(BundleTable.Bundles.ResolveBundleUrl(bundleUrl)) : UnbundledFiles(bundleUrl);
22               }
23               
24               private static MvcHtmlString BundledFiles(string bundleVirtualPath)
25               {
26                   return new MvcHtmlString(string.Format(CssTemplate, bundleVirtualPath));
27               }
28          
29               private static MvcHtmlString UnbundledFiles(string bundleUrl)
30               {
31                   var bundle = BundleTable.Bundles.GetBundleFor(bundleUrl);
32          
33                   StringBuilder sb = new StringBuilder();
34                   var urlHelper = new UrlHelper(HttpContext.Current.Request.RequestContext);
35          
36                   foreach (var file in bundle.EnumerateFiles(new BundleContext(new HttpContextWrapper(HttpContext.Current), BundleTable.Bundles, bundleUrl)))
37                   {
38                       sb.AppendFormat(CssTemplate + Environment.NewLine, urlHelper.Content(ToVirtualPath(file.FullName)));
39                   }
40          
41                   return new MvcHtmlString(sb.ToString());
42               }
43          
44               private static string ToVirtualPath(string physicalPath)
45               {
46                   var relativePath = physicalPath.Replace(HttpContext.Current.Request.ServerVariables["APPL_PHYSICAL_PATH"], "");
47                   return relativePath.Replace("\\", "/").Insert(0, "~/");
48               }
49          
50               public static MvcHtmlString CssBundle(this HtmlHelper helper, string bundleUrl)
51               {
52                   return ResolveBundleUrl(bundleUrl);
53               }
54           }

To summarize, I’m using the same technique to determine debug mode, and of course this could be extended to conditionally bundle or not based on any boolean. The interesting code is in the UnbundledFiles(string bundleUrl) method.

Currently, there is no concept of named bundles – bundles are specified simply by the virtual path of the resultant bundle. This means all our calling code in the view has to give is the virtual path of the bundle. We have to start from that and uncover all the physical files deeper within the BundleTable.

var bundle = BundleTable.Bundles.GetBundleFor(bundleUrl);

This line retrieves the bundle that we created from the BundleTable.

bundle.EnumerateFiles(new BundleContext(new HttpContextWrapper(HttpContext.Current), BundleTable.Bundles, bundleUrl))

This gets all of the physical files from the bundle.

The rest is just boilerplate code to turn those raw physical files back into relative virtual paths and into the proper html tags.

Finally, you’ll note that I have an HtmlHelper method in there, CssBundle(this HtmlHelper helper, string bundleUrl). To render a bundle link in a view, this must be used. Since the result of a bundle could be one or multiple files, I decided the simplest approach would be to allow the BetterBundler to render the full html tag itself. This could easily be changed or enhanced.

1              In the view:
2             
3              @Html.CssBundle("~/content/css")

The Result

In release mode:

<link href="/content/css?v=7GiB-1k9Pr1JbbYY72bT3T2EOpxXf0rGPdEOXVKl5oQ1" rel="stylesheet" type="text/css" />

In debug mode:

<link href="/content/test.css" rel="stylesheet" type="text/css" />
<link href="/content/site.css" rel="stylesheet" type="text/css" />

In this article I will show you how to publish ASP.NET web application. I have found many people ask this question on asp.net forum. You can simply publish your web application to the File System and copy paste all the files to your server. Then from IIS, you can add a new website. You can set this by right clicking on the web application in the solution explorer and choosing 'Package/Publish Settings'.

Right click on your project in the solution explorer and choose 'Publish'. From the dialog box, as the publish method, choose 'File System'. And choose some directory as the Target Location.

Add the website by right clicking on the 'Sites' in IIS.

Then give a name to your site and select the Physical path from where you copied the site folder.

Many times in software development, we want to invoke several processes at one time and continue when we get all the results back.  Obviously, if we were needing to process a sequence of items in a similar matter, we could use PLINQ.  Unfortunately, when the things we want to invoke asynchronously are heterogeneous tasks, PLINQ doesn’t really fit the bill.  Today we will look at a handy method in the Parallel class that can help us accomplish this.

Invoking processes asynchronously

Let’s say we have three completely separate methods and we want to invoke all three of them and the continue when they have returned.  These methods may be from separate classes and have completely different parameters and/or return types.  Thus, it may not be possible to use facilities likeParallel.ForEach() or PLINQ.

So how would we do this?  Well, we could obviously create three threads, start them, and join on them to come back:

   1: var threads = new List<Thread>
   2:                   {
   3:                       new Thread(SomeMethod),
   4:                       new Thread(() => SomeOtherMethod(x, y)),
   5:                       new Thread(() => { result = YetAnotherMethod(x, y, z); })
   6:                   };
   7: threads.ForEach(t => t.Start());
   8: threads.ForEach(t => t.Join());

Which, as you can see, can be used to call any method that fits Thread’s constructor (or can be adapted to it using a lambda, etc.). 

But that’s a bit heavy.  In addition, if an unhandled exception is thrown in one of those methods it will kill the thread, but we don’t have a very clean way of catching it here at the point of invocation.

Of course, we also have the Task class from the TPL which can help simplify threads:

   1: var tasks = new []
   2:                 {
   3:                     Task.Factory.StartNew(SomeMethod),
   4:                     Task.Factory.StartNew(() => SomeOtherMethod(x, y)),
   5:                     Task.Factory.StartNew(() => { result = YetAnotherMethod(x, y, z); })
   6:                 };
   7: Task.WaitAll(tasks);

This simplifies things on the surface, and better yet simplifies things a lot more with exception handling as well (TPL task exceptions get wrapped into a AggregateException and can be caught at the WaitAll() – and other possible places).

But there’s an even easier way…

Parallel.Invoke() – Easily invoke asynchronously

Just as the TPL gave us Parallel.For() and Parallel.ForEach() to make processing loops asynchronously a breeze, it also gave us Parallel.Invoke(), which takes any number of Action delegates and invokes them asynchronously and waits for them to rejoin.  If your methods have return values you want to store or need parameters, you can easily use lambda expressions as well:

   1: Parallel.Invoke(
   2:     SomeMethod,
   3:     () => SomeOtherMethod(x, y)),
   4:     () => { result = YetAnotherMethod(x, y, z); })

As long as the method can convert to an Action or you can form a lambda that will allow it to do so, you can use the Parallel.Invoke() to easily call them all in parallel without having to worry about starting or joining the threads or tasks.  And, because this is part of the TPL, you get the nice AggregateException handling as well that lets you easily catch tasks thrown from the underlying tasks.

Summary

When you just need to fire off several methods in parallel, consider the Parallel.Invoke().  It is a very handy way to invoke several different methods easily without having to worry about all the details of creating tasks or threads.