Monday, August 15, 2011

asp RangeValidator cannot convert MaximumValue in foreign Cultures

Recently I added a range validator to 1 of our controls which is supposed to ensure that a value is between 0.1 - 50. In our application's default culture (which is en-GB) the validator works fine.

However during our localization exercise we realized that the validator throws an exception for certain cultures (in this case, when we ran the application in de-DE)

The declaration of my control is as follows:

< asp:RangeValidator ID="RangeValidator1" runat="server" ControlToValidate="SomeTextBox1" MinimumValue="0.1" MaximumValue="50" Type="Double" />

The runtime exception that was thrown was:

The value '0.1' of the MinimumValue property of 'RangeValidator1' cannot be converted to type 'Double'.
at System.Web.UI.WebControls.RangeValidator.ValidateValues()
at System.Web.UI.WebControls.RangeValidator.ControlPropertiesValid()
at System.Web.UI.WebControls.BaseValidator.get_PropertiesValid()
at System.Web.UI.WebControls.BaseValidator.OnPreRender(EventArgs e)


Well its simple. German's equivalent of 0.1 is 0,1 (with a comma instead of a dot). And when the thread is running in the german culture, it doesn't know how to convert 0.1. IMO, this is a bug in the framework. The range validator (or any other control for that matter) must not consider the culture for values that are set during design time.


What i did was;

MinimumValue='<%# (0.1).ToString(System.Globalization.CultureInfo.CurrentCulture) %>'

This way, I'm not hardcoding anything in design time. during run time the value will be set to the control in the current thread's culture. You can also do this in code behind. But I didn't have the option of recompiling the library :)

Wednesday, May 18, 2011

How to start numbering from 3rd page in MS Word 2007

Are you trying to submit your assignment before deadline? Has your report exceeded the maximum page limit? Do you want to save a few pages by not numbering your content page? Are you frustrated because the deadline is tomorrow and the page numbering is not coming right? If your answer is YES to any of these questions, I know how you feel.

Here's how to do it!

  1. Place the cursor behind the 1st letter of the page you want to start your numbering from.
  2. Go to Page Layout tab and click on Breaks
  3. From the menu, select Next Page which is under Section Breaks

This will break the content and the report in to 2 separate sections. Now you can number these sections independently of each other. To start putting page numbers, follow these steps:

  1. Place the cursor anywhere on the section you want to number. (say this is your 3rd page where you start off with your introduction)
  2. Go to Insert tab
  3. Click on Page Number menu and select a position for your page numbering

Once you do this, numbering will start from the 1st page itself. now you need to tell word that you want to number only the current section;

  1. Place the cursor anywhere on the section you want to number. (say this is your 3rd page where you start off with your introduction)
  2. Go to Insert tab
  3. Click on Page Number and select Format Page Numbers...
  4. In the Page Number Fortmat dialog box, set the Page Numbering to Start at: 1

Now you will see that there are no page numbers in your content pages, and numbers are starting from the body of the report.

Similarly if you have different sections in your report such as the preface, appendices, etc. all you need to do is make sure they are broken in to separate sections, before you put page numbering.

Saturday, April 9, 2011

Telerik RadGrid doesn't fire NeedDataSource event on Rebind()

So you're using telerik, and you want your NeedDataSource method to get called when you rebind. But it doesnt?

This is a problem I face every now and then. Each time I struggle to remember the resolution from last time but keep forgetting. Just got the same error so this time, decided to put it down here.

An event handler for the event NeedDataSource has been properly subscribed.



<telerik:RadGrid ... OnNeedDataSource="Gird_NeedDataSource">

Code behind:

protected void Grid_NeedDataSource(object source, GridNeedDataSourceEventArgs e)
// Logic to load data

private void SomeMethod()


make the datasource of the grid null before calling rebind.
Grid.DataSource = null;

Most likely you are not adhering to the standard way the RadGrid is supposed to be implemented (which is OK in my opinion).

If you place a break point in your existing NeedDataSource event handler, you will notice that it gets called before you explicitly call Rebind.

This means you most probably set the Grid.DataSource property within the NeedDataSource event. Therefore when the DataSource property is not null, that should mean that there is 'NO need for a data source'.

Therefore quite naturally the NeedDataSource event will not get fired when you rebind the grid.
I believe this is the expected behavior of the RadGrid. If you ever have a need to explicitly set the DataSource to null before calling rebind, that means something is not following the expected standard in your code. Oh well, you have to live with it right?

If you know of any other reasons as to why the NeedDataSource wouldn't get called on rebinding the grid, feel free to post a comment on it :)

Thursday, April 7, 2011

Script control 'ControlName' is not a registered script control

So you're here because you got the following error.

Script control 'ControlName' is not a registered script control. Script controls must be registered using RegisterScriptControl() before calling RegisterScriptDescriptors().

Parameter name: scriptControl

I myself have done a fair bit of googling on this, and there are many solutions given all over the net. unfortunately these are all very scenario specific solutions. Some people get their answers, and the others, like me, don't.


You are changing the visibility of a control at the wrong stage of the page life cycle.


If you are changing the visibility of a control, you should always do it during, or before the PreRender event. If you do it after (i.e. in a End handler of an async task or during PreRenderComplete) you might run in to this issue.

This is not an issue for simple controls such as buttons or text boxes. But it will have adverse effects on controls such as grids.

When I say changing the visibility it could be any one of the following situations

  • Having visible=false of a control during the early stages of the life cycle and being changed to visible=true during an end handler or PreRenderComplete
  • Changing the selected view of a MultiView during an end handler or PreRenderComplete
  • Any other situation where the control may not be visible during the earlier stages of the page life cycle which are set to be visible during the latter stage
Purely from my understanding, ASP.NET does not render the scripts or the HTML related to a control if it is not being shown to the user. The registering of script controls which is mentioned in the exception seem to happen during an early stage of the life cycle. if the control is not visible at this stage, this registration is skipped for that control. If it's made to be visible at a latter point, you get yourself a control without some of the relevant scripts.

Anyway this is what I have understood. I may be wrong. But if you come across this issue, it will definitely help you to check for controls which are changing visibility at different points of the life cycle. You will be able to identify your specific problem by doing this and then come up with a solution on your own.

Hope this information helps some one.

Thursday, March 10, 2011


This is something i've been meaning to do for a while. Basically I'll be putting up posts on how I've solved certain problems I've faced in life. This is mainly for my own reference. and hopefully someone else will make use of it too.

I am a software developer so the content will be mainly on tech stuff. Other than that i might even post my secret BBQ recipe and the likes.

So... Here we go...