What is the correct setting of ClientIDMode in ASP.Net 4 to get ASP.Net 2.0 rendering.
We have just updated our application from ASP.Net 2.0 to ASP.Net 4.0.
We have included in the web.config in the <system.web> element:
<pages controlRenderingCompatibilityVersion="3.5" clientIDMode="AutoID" />
My understanding is that this is supposed to render the controls the same as .Net 2.0/3.5 would.
However... it's not... here is one example
This is rendered in 2.0:
<input id="grdUserEntity__ctl1_chkSelectAll" type="checkbox"
name="grdUserEntity:_ctl1:chkSelectAll" onclick="javascript:iSelectAll();" />
This is in 4.0:
<input id="grdUserEntity_ctl01_chkSelectAll" type="checkbox"
name="grdUserEntity$ctl01$chkSelectAll" onclick="javascript:iSelectAll();" />
The difference:
2.0 id=grdUserEntity__ctl1_chkSelectAll
4.0 id=grdUserEntity_ctl01_chkSelectAll
According to what I read that config setting will cause ASP.Net 4.0 to render the server controls and client id's identically to the previous version.
What are we doing wrong?
Answer
There was a change to how IDs were rendered from ASP.NET 2.0 to ASP.NET 3.5. Since you're going from 2.0 to 4.0, you're still seeing that difference. The change was due to XHTML compliance improvements.
You can try switching back to the 2.0 rendering with the xhtmlCompliance compat setting. Yet another compat setting, yes :) It should work, but honestly, I'm not sure how well tested that old compat setting is in 4.0, and I know it wouldn't be compatible with the UpdatePanel, if you were planning on using that.
Is there a reason why you want to keep the 2.0 rendering? Just fear of regressions, or do you have any known actual regressions?
XHTML setting: http://msdn.microsoft.com/en-us/library/ms178159.aspx