We’ve recently received a few reports of an issue in the Visual Studio .NET Web Forms Designer that I wanted to make everyone aware of. While this issue occurs infrequently, it can sometimes result in data loss on a Web Form, so it’ll be important to take steps to avoid the issue in the near-term. In addition, our product team is currently working to provide a hotfix for this issue. We’ll be making the hotfix available for download from our Web site within the next few days. As soon it’s ready, I’ll post another message to this NG. In the meantime, I was able to recreate the issue and identify a series of steps that people can take to avoid the problem. I’ve included a description of the issue and the steps to avoid it below:


Scenario and Symptoms:
This issue occurs when building ASP.NET Web applications using the Web Forms designer. In particular, you will run across this case when switching from WYSIWYG (Web Forms designer) view to the code-behind view *before* the WYSIWYG designer view finishes loading. This scenario typically happens when your Web Form contains numerous controls, causing a slight delay for the form to finish loading. The result of this scenario is that form data, including controls, will disappear.



Resolution:
While there is no way to reverse the process once it has occurred, the best way to resolve this issue is to avoid it in the first place. There are 3 visual cues that indicate the loading of the form is actually complete:

- The Visual Studio .NET Status Bar updates to say “Ready”

- The Visual Studio .NET Property Grid updates with information on the form

- The HTML document outline tree updates with current form information (Note: While this is the most reliable method for ensuring that the form has completely loaded, this tool window is not open by default. You can open this window by selecting View..Other Windows..Document Outline)

So, anytime you are switching to Web Forms designer view in an ASP.NET application, you should use these 3 visual cues in order to ensure that the form has completed loading. Once you have verified that the form has loaded, you can switch back to the code-behind view, run the application, etc., without running into this data loss problem.

Again, as soon as the hotfix is ready for download, I’ll post another message to this NG. Thanks in advance for your understanding.

yag