Silverlight Multiple Application Debugging

Question

I have three Silverlight 3 applications in the same solution. In my asp.net hosting project I have a seperate page for all three projects. When I navigate between the pages, the only Silverlight breakpoints that get hit are the ones the initial page I load.

This problem has only started recently. I used to be able to debug between all silverlight projects at the same time. Any ideas? I have deleted the ClientBin folder, I have deleted all files and re-retrieved from source control. Nothing seems to be working.

Answer 1

"The problem has only started recently". What changed? Here are some guesses:-

• You upgraded to Windows 7
• You installed some more memory
• Some other memory guzzling app is no longer running when you are testing.

By default IE8 will run multiple processes at least 2. One for the browser frame and one for the content of the intial tab. As you open more windows and tabs IE may add new processes to the set it is currently using.

When you debug VS will launch an new IE8 session and will attach to the process handling the content of the single tab that is open, (it doesn't bother attaching to the parent frame process). However as you navigate about your application IE8 will start new process that VS won't be attached to. This forces you to open the Attach to Process dialog and do it manually.

You can control this IE8 feature (called BTW LCIE, Loosely Coupled IE) from the Registry.

In the Key HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main add a new DWORD value TabProcGrowth. Set its value to 1. Now IE8 will only ever create 2 processes per session one for the frame and one for all the tab and window contents which is the one the VS will attach to.

This perhaps is a bit draconian if you also use IE8 as your general browser. One option is to leave IE8 for test purposes and use another browser for general browsing. Another option is a variation of the above. Instead of creating TabProcGrowth as a DWORD create it as a string type instead and set is value to "small". In this mode IE8 is much less aggressive in the number of processes it will open. Of course you could create a couple of scripts to create and delete the registry entry.

Note without the registry entry IE8 uses its own hueristics that depends on available memory etc to determine if a new process is warrented or not. This might explain why in the past your debugging worked and that for apparently no reason it stopped working.

Answer 2

Here was the issue:

One of my child windows had a Silverlight that calling a .Net Ria Service. The service call ended in an error.

The next time several I debugged, the debugger did not attach to the child windows. I had to attach to the child windows manually.

I fixed the Ria Service call so that it did not end in an error. And had to manually attach to the child windows in that debugging session. However in subsequent debugging sessions, the debugger automatically attached.

I tried breaking the Ria Service call and I had to manually attache again. What is a little weird is that closing Visual Studio and even rebooting the machine does not make Visual Studio automatically attach again. You have to have a debugging session where the child window make a sucessful call to a Ria Service to fix it.

NOTE: The RIA error that was breaking my debugger was caused by a misspelled include in the domain query (ie...

return Context.SOME_ENTITY.Include("Misspelled_Association_Property");

) not all RIA exceptions cause this problem.

My scenario has a number of specific cases that I will go over. I don't have all the things handy to test a more general scenario, but I will when I finish my project unless someone does this first.

Here is what I have:

I am using the a LinqToEntitiesDomainService from the July 2009 Preview release of .Net RIA Services.

To complicate things a little more, since my application is using an Oracle backend, I am using DevArt's dotConnect Entities provider as the EntityFramework model for my domain service.

When I get time, I will try this on the Nov 2009 RIA and a standard SQL backend and EF to see if I still have the same issue. If this is the case I will report it to Microsoft as a visual studio bug.