HTTP Error 404.13 – Not Found – The request filtering module is configured to deny a request that exceeds the request content length.

I recently got this error in one of my applications. When troubleshooting, I found my application is configured to have the default value of 30000000 Bytes for the content length, which was not sufficient for me in some of the file uploading functionalities.

Simply adding / increasing the number in the configuration file corrected this error.

Request Content Length in Bytes.

Default Value – 30000000 Bytes (~28MB)

Maximum Value – 4284229877 Bytes (3.99GB)

1. <system.webServer>
2.   <security>
3.     <requestFiltering>
4.       <requestLimits maxAllowedContentLength="100000000"></requestLimits>
5.     </requestFiltering>
6.   </security>
7.   ...
8. </system.webServer>

 

To obtain more information read this article.

Handler was not added through the Sys.UI.DomEvent.addHandler method.

Sometime back I started getting this error in all the forms in which AJAX tools were used. The thing worried me most is that there were no changes made to the project source code. Later a friend of mine found that it is happening because of the wrong AjaxControlToolkit.

As I feel this dll swap happens when a control is dragged from the Visual Studio toolbox because the toolbox is referenced to a newer version of the toolkit than the project was using.

If you are also getting this error simply delete all the AJAX related files and folders in your projects’ bin directory. Once you are done there should not be any folders such as ar, cs, de, etc. Also remove the AjaxControlToolkit.dll. Then copy the version of the toolkit dll your project was using earlier to the Bin directory. Now clean and build your project to see the error disappear.

If you are still getting the error after correctly doing all this you might be getting the error due to another reason causing the same error. Since there are many reasons for this same error you better check the internet for other reasons to find out the exact reason causing the error for you.

Correcting AJAX Calendar Extender Popup Calendar Position

Recently I encountered a positioning error in AJAX calendar extender. When I use the calendar extender inside of other container controls the popup calendar started appearing few inches above the button. You will be able to get an idea of the problem by the following image.

Since I couldn’t get it fixed by changing the properties I thought to find a solution for this.

One way to correct this is by applying a CSS style sheet to change the calendar positioning manually. I found this method while searching the web. This way since you need to enter the location of the calendar you need to try several times to get the correct positioning. If you are using this method simply place the following CSS style in your page and apply the style as shown. Remember you need to change the value to suit your form.

1. <style type="text/css">
2.     .fromDtPos
3.     {
4.         left: 245px !important;
5.     }
6. </style>

Apply the style to your calendar extender.

1. <cc2:calendarextender id="calExpiry" runat="server" targetcontrolid="txtExpiry"
2.     format="dd MMM yyyy" popupbuttonid="imgExpiry" enabled="True" cssclass="ajax__calendar fromDtPos">
3. </cc2:calendarextender>

My preferred way to do this is by using the JavaScript that I wrote below. Since you do not need to enter the position manually this will be easier. Also this code will work irrespective of the number of parent containers it is having above of the control.

Insert the below JavaScript into your page.

1. <script type="text/javascript" language="javascript">
2.     function showCalendar(sender, args) {
3.         var processingControl = $get(sender._button.id); // Getting the control which triggered the calendar.
4.         sender._popupDiv.parentElement.style.top = processingControl.offsetTop + processingControl.height + 'px';
5.         sender._popupDiv.parentElement.style.left = processingControl.offsetLeft + 'px';
6.  
7.         var positionTop = processingControl.height + processingControl.offsetTop;
8.         var positionLeft = processingControl.offsetLeft;
9.         var processingParent;
10.         var continueLoop = false;
11.  
12.         do {
13.             // If the control has parents continue loop.
14.             if (processingControl.offsetParent != null) {
15.                 processingParent = processingControl.offsetParent;
16.                 positionTop += processingParent.offsetTop;
17.                 positionLeft += processingParent.offsetLeft;
18.                 processingControl = processingParent;
19.                 continueLoop = true;
20.             }
21.             else {
22.                 continueLoop = false;
23.             }
24.         } while (continueLoop);
25.  
26.         sender._popupDiv.parentElement.style.top = positionTop + 'px';
27.         sender._popupDiv.parentElement.style.left = positionLeft + 'px';
28.     }
29. </script>

Then call the function showCalendar on onClientShown event of the calendar extender as seen below.

1. <cc2:calendarextender id="calExpiry" runat="server" targetcontrolid="txtExpiry"
2.     format="dd MMM yyyy" popupbuttonid="imgExpiry" enabled="True" onclientshown="showCalendar">
3. </cc2:calendarextender>

Both of the above methods will correct the appearance of the popup calendar of the AJAX Calendar Extender as seen below.

Styles missing in CalendarExtender

When you put an Ajax Calendar Extender inside of a GridView you will see the calendar without any styling on it meaning the calendar will show only the dates overlapping with other items on your form. Sometimes some dates might even be missing. See the sample appearances below.

This happens because the style sheets are not loaded at the correct time due to a bug in toolkit, there are several ways to fix this.

One is to add another calendar extender outside of the update panel and keep it hidden.

Another is to disable partial rendering in the script manager. But this will slow down your site reducing the benefits gained from AJAX.

1. <asp:ScriptManager ID="ScriptManager1" EnablePartialRendering="false" runat="server">
2. </asp:ScriptManager>

My chosen method is to add the styles manually to the style sheet. To move forward this way simply copy the following styles which are used by the calendar extender to your style sheet.

1. .ajax__calendar_container {padding:4px;cursor:default;width:170px;font-size:11px;text-align:center;font-family:tahoma,verdana,helvetica;}
2. .ajax__calendar_body {height:139px;width:170px;position:relative;overflow:hidden;margin:auto;}
3. .ajax__calendar_days, .ajax__calendar_months, .ajax__calendar_years {top:0px;left:0px;height:139px;width:170px;position:absolute;text-align:center;margin:auto;}
4. .ajax__calendar_container TABLE {padding:0px;margin:0px;font-size:11px;}
5. .ajax__calendar_container TD {padding:0px;margin:0px;font-size:11px;}
6. .ajax__calendar_header {height:20px;width:100%;}
7. .ajax__calendar_prev {cursor:pointer;width:15px;height:15px;float:left;background-repeat:no-repeat;background-position:50% 50%;background-image:url(../images/arrow-left.gif);}
8. .ajax__calendar_next {cursor:pointer;width:15px;height:15px;float:right;background-repeat:no-repeat;background-position:50% 50%;background-image:url(../images/arrow-right.gif);}
9. .ajax__calendar_title {cursor:pointer;font-weight:bold; margin-left:15px; margin-right:15px;}
10. .ajax__calendar_footer {height:15px;}
11. .ajax__calendar_today {cursor:pointer;padding-top:3px;}
12. .ajax__calendar_dayname {height:17px;width:17px;text-align:right;padding:0 2px;}
13. .ajax__calendar_day {height:17px;width:18px;text-align:right;padding:0 2px;cursor:pointer;}
14. .ajax__calendar_month {height:44px;width:40px;text-align:center;cursor:pointer;overflow:hidden;}
15. .ajax__calendar_year {height:44px;width:40px;text-align:center;cursor:pointer;overflow:hidden;}
16.  
17. .ajax__calendar .ajax__calendar_container {border:1px solid #646464;background-color:#ffffff;color:#000000;}
18. .ajax__calendar .ajax__calendar_footer {border-top:1px solid #f5f5f5;}
19. .ajax__calendar .ajax__calendar_dayname {border-bottom:1px solid #f5f5f5;}
20. .ajax__calendar .ajax__calendar_day {border:1px solid #ffffff;}
21. .ajax__calendar .ajax__calendar_month {border:1px solid #ffffff;}
22. .ajax__calendar .ajax__calendar_year {border:1px solid #ffffff;}
23.  
24. .ajax__calendar .ajax__calendar_active .ajax__calendar_day {background-color:#edf9ff;border-color:#0066cc;color:#0066cc;}
25. .ajax__calendar .ajax__calendar_active .ajax__calendar_month {background-color:#edf9ff;border-color:#0066cc;color:#0066cc;}
26. .ajax__calendar .ajax__calendar_active .ajax__calendar_year {background-color:#edf9ff;border-color:#0066cc;color:#0066cc;}
27.  
28. .ajax__calendar .ajax__calendar_today .ajax__calendar_day {border-color:#0066cc;}
29. .ajax__calendar .ajax__calendar_today .ajax__calendar_month {border-color:#0066cc;}
30. .ajax__calendar .ajax__calendar_today .ajax__calendar_year {border-color:#0066cc;}
31.  
32. .ajax__calendar .ajax__calendar_other .ajax__calendar_day {background-color:#ffffff;border-color:#ffffff;color:#646464;}
33. .ajax__calendar .ajax__calendar_other .ajax__calendar_year {background-color:#ffffff;border-color:#ffffff;color:#646464;}
34.  
35. .ajax__calendar .ajax__calendar_hover .ajax__calendar_day {background-color:#edf9ff;border-color:#daf2fc;color:#0066cc;}
36. .ajax__calendar .ajax__calendar_hover .ajax__calendar_month {background-color:#edf9ff;border-color:#daf2fc;color:#0066cc;}
37. .ajax__calendar .ajax__calendar_hover .ajax__calendar_year {background-color:#edf9ff;border-color:#daf2fc;color:#0066cc;}
38.  
39. .ajax__calendar .ajax__calendar_hover .ajax__calendar_title {color:#0066cc;}
40. .ajax__calendar .ajax__calendar_hover .ajax__calendar_today {color:#0066cc;}
41.  
42. /* styles for invalid dates as defined by startDate and endDate*/
43. .ajax__calendar .ajax__calendar_invalid .ajax__calendar_day {background-color:#ffffff;border-color:#ffffff; color:#646464; text-decoration:line-through; cursor:default;}
44. .ajax__calendar .ajax__calendar_invalid .ajax__calendar_month {background-color:#ffffff;border-color:#ffffff; color:#646464; text-decoration:line-through; cursor:default;}
45. .ajax__calendar .ajax__calendar_invalid .ajax__calendar_year {background-color:#ffffff;border-color:#ffffff; color:#646464; text-decoration:line-through; cursor:default;}
46.   .ajax__calendar .ajax__calendar_invalid .ajax__calendar_today{visibility:hidden; cursor:default;}

Note that the above CSS uses the “arrow-left.gif” and “arrow-right.gif” for the previous and next buttons. If you want, you can use any other image which suits you. In case you need the originals they are below. To correctly show the previous and next buttons you need to place these images on to the “Images” folder under your project. If the folder is different in your project please change the image paths in the above CSS.

• arrow-left.gif -
• arrow-right.gif -

After doing all this remember to link the style sheet to your web page.

1. <link href="Styles/Site.css" rel="stylesheet" type="text/css" />

If you have done everything correctly your calendar will be shown properly while residing inside of the grid.

Developing iPhone and Android Applications using C# .Net

Being a .Net developer did you think how great if you could develop applications for most popular mobile device platforms like iPhone and Android with the .Net skills you already have. If you were thinking like me then the wait is over.

Now with Mono you can create cross platform applications using your .Net framework skills. Mono is a software platform using which you can develop applications which runs on iPhones, Android devices, iPads and iPod Touches.

As per the Mono site, “The Mono Project is an open development initiative sponsored by Novell to develop an open source, UNIX version of the Microsoft .NET development platform.” If you are wondering about the name Mono, it is 'monkey' in Spanish.

You can try Mono for free by downloading the trial by going to the trial link. The good thing is after installing Mono you can use the more familiar Visual Studio to do the development using the available Mono templates.

TechEd Australia – Videos

As you might know TechEd Australia ended few weeks back. I am sure lot of you might not have the chance to visit it. The good thing is you can watch the recorded sessions online now by visiting the following site.

http://channel9.msdn.com/events/teched/australia/tech-ed-australia-2011

I think this will be mostly useful to people who didn’t visit TechEd and also to people who visited it to refresh their minds.

Class not registered

Recently when I tried to build and run an existing .Net application code I got the following error which generated from a component named “axShockwaveFlash1” which is an object used to embed flash content on to the application.

System.Runtime.InteropServices.COMException was unhandled   Message=Class not registered (Exception from HRESULT: 0x80040154 (REGDB_E_CLASSNOTREG))   Source=System.Windows.Forms   ErrorCode=-2147221164   StackTrace:        at System.Windows.Forms.UnsafeNativeMethods.CoCreateInstance(Guid& clsid, Object punkOuter, Int32 context, Guid& iid)        at System.Windows.Forms.AxHost.CreateWithoutLicense(Guid clsid)        at System.Windows.Forms.AxHost.CreateWithLicense(String license, Guid clsid)        at System.Windows.Forms.AxHost.CreateInstanceCore(Guid clsid)        at System.Windows.Forms.AxHost.CreateInstance()        at System.Windows.Forms.AxHost.GetOcxCreate()        at System.Windows.Forms.AxHost.TransitionUpTo(Int32 state)        at System.Windows.Forms.AxHost.CreateHandle()        at System.Windows.Forms.Control.CreateControl(Boolean fIgnoreVisible)        at System.Windows.Forms.Control.CreateControl(Boolean fIgnoreVisible)        at System.Windows.Forms.AxHost.EndInit()        at Tour_Management_System.Loading_Form.InitializeComponent() in D:\Projects\Acc\TMS_20100205_Desktop\Tour_Management_System 2010-01-19\Tour_Management_System\Form1.Designer.cs:line 99        at Tour_Management_System.Loading_Form..ctor() in D:\Projects\Acc\TMS_20100205_Desktop\Tour_Management_System 2010-01-19\Tour_Management_System\Form1.cs:line 30        at Tour_Management_System.Program.Main() in D:\Projects\Acc\TMS_20100205_Desktop\Tour_Management_System 2010-01-19\Tour_Management_System\Program.cs:line 18        at System.AppDomain._nExecuteAssembly(Assembly assembly, String[] args)        at System.Runtime.Hosting.ApplicationActivator.CreateInstance(ActivationContext activationContext, String[] activationCustomData)        at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssemblyDebugInZone()        at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)        at System.Threading.ThreadHelper.ThreadStart()   InnerException:

After some investigation I found that the reason for this was Flash Player’s incompatibility with 64 bit. Since my machine is running Windows 64 bit version it generates an error while trying to start Flash player. Good thing is Adobe is planning to release a Flash player which supports 64 bit soon.

For people who cannot wait until that (like me) can fix the problem in the following manner by running the application as an x86 application by changing the target platform in project properties.

Step 1 - Right click on your project and click on the properties.

Step 2 - Click on the Build tab and select x86 as the Platform target:.

Step 3 - Rebuild the application and run it, you will not get the error.

Visual Studio not Showing Errors

Is your Visual Studio showing error line numbers and respective pages while you develop?
If not read on, recently I came up to a machine which was having Visual Studio error. Visual Studio was showing errors when a project is compiled but the error details (error code line number, error file) which we can use to identify the error are not displayed.
After trying out several things found the cause of it and thought to share it.
The problem was not with the project but with the path the project was kept.
In the machine the failing project was stored under a folder which was having parenthesis or brackets "(".
For example the solution path was like C:\ProjectsA(V1)\MyProj\.
The (V1) part was confusing Visual Studio making it stop displaying the error details.
If you also have the same problem simply remove the brackets by renaming the folder and reload your project to Visual Studio from the new path. The error details will be shown correctly.

HTML Meta Tags

Do you know what can be done with HTML Meta tags?
If not then you will also struggle when trying to do a page refresh or a redirect.
To get more details on how to please refer the following web site.
http://webdesign.about.com/od/metataglibraries/a/aa080300a.htm

Implementing a File Download in ASP.NET

Recently I gave some help to a colleague of mine implementing a file download. So I thought of sharing it with you.
If you need to make a web site user to download a file from your site you have to use HTTPResponse.Page.Response object. By using this you will be able to make the user download numerous kinds of files to their machines. The code required is as follows.

// This defines the type of the file that you are allowing to download.
Response.ContentType = "application/vnd.ms-excel";
// Path to the file to be downloaded.
string FilePath = MapPath("Xcel.xlsx");
// Initiating the file download.
Response.WriteFile(FilePath);
Response.End();

The above code will let the user download an Excel file named Xcel. Aprt from Excel you can use other file types as well by changin the Response.ContentType to the required file type.
A list of available content types are as follows.

Inserting a Double Quote in to a String in .NET

Even though this is not new I do forget this always, so thought of putting an entry on how we can put a double quote inside of a string.

VB.NET
Dim str As String = "Example String " & """" & "This is the String with double quotes." & """"
MessageBox.Show(str)

In VB.Net you can indicate that there is a double quote in a string by using 4 double quotes ("""").

C#.NET
string str = "Example String " + "\"" + "This is the String with double quotes." + "\"";
MessageBox.Show(str);

As you will notice in C# the double quote can be represented as double quote, back slash and again using two double quotes ("\"").

The above string will be displayed as follows.

Adding an existing Dataset to a project - VS.NET 2003

Did you try adding an existing typed dataset to a project in Visual Studio 2003?

If you did then you may have noted that it will only add the files having the extensions .xsd (designer file) and .xsx (resource file) to the project, it will not add the .vb (class file). As a result you will not be able to use the added dataset. Also if anyone tries to add the class file again manually then it will be there as a separate class. Even though this works fine it will be misleading at a latter stage of the projects life. (In the following image you can see the 'dsDataset1.vb' file separately.)

Normally this 'dsDataset1.vb' file should come under 'dsDataset1.xsd'.

To get the dataset class file recreated in the correct location,

• First open the dataset designer using Visual Studio (double click on the dataset).
• Then right click on the dataset designer and select the 'Generate Dataset' menu option.

Now you will see the class ('dsDataset1.vb') file nicely located under 'dsDataset1.xsd'.

Detecting Whether the Application is Already Running

Recently a colegue of mine needed to know how he can determine whether his application is already running in the machine at application start.

Using this post I am going to share the solution with you all, showing how you can determine whether your application is already running in the computer. By detecting this either you can stop starting of the second instance of the application and activate the already running application for the user or you can attempt to close the earlier application and start the new one. If you does not check this then multiple applications might start and the user might complain about the application performance. Also this may cause problems occurring from locked resources.

* Visual Basic (VB)
Using VB you can easily check this by using the App object.
------------------------------------------------------------
If App.PrevInstance = True Then
MsgBox("The program '" & App.EXEName & "'is already running. Please use the running application.")
End
End If
------------------------------------------------------------

* Visual Basic .NET (VB.NET)
Using VB.NET you can do this by using Diagnostics.Process class.
------------------------------------------------------------
If Diagnostics.Process.GetProcessesByName(Diagnostics.Process.GetCurrentProcess().ProcessName).Length > 1 Then
Application.Exit()
End If
------------------------------------------------------------