I am building a Web Application Project with Visual Studio 2005. On one page, I added a SqlDataSource with a connectionstring.

The problem is as follows: I get the warning "Generation of designer file failed: The expression prefix 'ConnectionStrings' was not recognized. Please correct the prefix or register the prefix in the <expressionBuilders> section of configuration."

My application runs well, but adding controls to this page does not update the .aspx.designer.cs code behind file.

Anyone who has a solution for this? I tried the <expressionBuilders> suggestion, but it did not work.

Thanks in advace.
 

<asp:SqlDataSource ID="SqlDataSource1" runat="server" ConnectionString="<%$ ConnectionStrings:ConnectionString %>"
                SelectCommand="SELECT * FROM [Tbl_Project]"></asp:SqlDataSource>

cheers 

I had the same problem. When I would view the xxx.designer.vb file, any new controls added to the page would not get added to that file.

I completely removed the datasource, then re-added it and things went back to working correctly.

Nevermind. I worked until I made any code changes. I just put the connection string right in the markup page, and it works that way.

I've been getting this problem and i'm suprised how little info there is out there.

My sites are 1.1 conversions too and i've followed every suggestion i've been able to find with no luck.

Basically, yes you can use a connection string directly inline but with a lot of pages this becomes unmanageable.

It seems that the error:

 Generation of designer file failed:  The expression prefix “ConnectionStrings” was not recognized.  Please correct the prefix or register the prefix in the <expressionBuilders> section of configuration.

stops the designer file from being modified with any new controls added. When this error is detected the whole designer generation process is stopped.

Anyone else had this and solved it as opposed to working around it?

mediademon

We've been experiencing the same error on a project that has not been converted at all.  Moreover, the issue popped up half way through development of the application and had previously been working fine.

Has anyone found any solutions?
 

I still haven't found a solution, i'm still not using connectionstrings in my datasources...

mediademon