“无可用源” - Visual Studio调试（即使已加载符号）

Question

I have set up Visual Studio 2012 Professional to download debug symbols. It is set up correctly and the symbols have downloaded.

I get to the line of code I wish to step into:

bool result = Membership.ValidateUser("user", "password");

I right click on it and choose step into specific-->Membership.ValidateUser()

Then a tab opens in Visual Studio saying:

No Source Available - There is no source code available for the current location

Membership.ValidateUser() is in the System.Web.Security namespace which is in the System.Web.dll . If I open up the Modules window I can clearly see that the symbols for this assembly have been downloaded.

If the symbols are there, why am I not able to step into the source code?

Answer 1

You may have the Symbols but you DON't have the source code. PDB's are not sufficient for debugging but they are necessarily to link your source code with the executable. PDB's are good to report bugs because they provide detailed information of call stack, in order to debug though, you need to have the source code.

Answer 2

Source stepping is only available for RTM or SP releases. See PDB files for .NET Framework 3.5 SP1 not available! (ie System.Web.pdb 2.0.50727.4016) .

Answer 3

I ran into the same problem and in my case it is version 4.0 and not 4.5, but still the same problem.

After checking with fiddler it appears that for many DLL files the server at referenceserver.microsoft.com returns 404 and Visual Studio then falls back and downloads it from the Microsoft symbol server at msdl.microsoft.com which doesn't contains the actual source code.

So at the end of the day, source stepping with Microsoft's code doesn't appear to always work, and one might resort to using .NET Reflector .

I have just found another Stack Overflow answer, .NET framework source stepping not working despite options set , and according to it the problem might be related to SP1.

Answer 4

I had the similar problem, and this is how I solved it.

Right click your project -> Properties - > Compile -> Advanced Compile Options...

Then Set 'Generate debug info' to 'Full' from the drop down menu.

Hope that helps.