How to debug external class library projects in visual studio?

Question

Try disabling Just My Code (JMC).

• Tools > Options > Debugging
• Uncheck "Enable Just My Code"

By default the debugger tries to restrict the view of the world to code that is only contained within your solution. This is really heplful at times but when you want to debug code which is not in your solution (as is your situation) you need to disable JMC in order to see it. Otherwise the code will be treated as external and largely hidden from your view.

EDIT

When you're broken in your code try the following.

• Debug > Windows > Modules
• Find the DLL for the project you are interested in
• Right Click > Load Symbols > Select the Path to the .PDB for your other project

Assume the path of

Project A

C:\Projects\ProjectA

Project B

C:\Projects\ProjectB

and the dll of ProjectB is in

C:\Projects\ProjectB\bin\Debug\

To debug into ProjectB from ProjectA, do the following

1. Copy B's dll with dll's .PDB to the ProjectA's compiling directory.
2. Now debug ProjectA. When code reaches the part where you need to call dll's method or events etc while debugging, press F11 to step into the dll's code.

NOTE : DO NOT MISS TO COPY THE .PDB FILE

This has bugged me for some time. What I usually end up doing is rebuilding my external library using debug mode, then copy both .dll and the .pdb file to the bin of my website. This allows me to step into the libarary code.

I run two instances of visual studio--one for the external dll and one for the main application.
In the project properties of the external dll, set the following:

Build Events:

• copy /y "$(TargetDir)$(TargetName).dll" "C:\<path-to-main> \bin\$(ConfigurationName)\$(TargetName).dll"

• copy /y "$(TargetDir)$(TargetName).pdb" "C:\<path-to-main> \bin\$(ConfigurationName)\$(TargetName).pdb"

Debug:

• Start external program: C:\<path-to-main>\bin\debug\<AppName>.exe

• Working Directory C:\<path-to-main>\bin\debug

This way, whenever I build the external dll, it gets updated in the main application's directory. If I hit debug from the external dll's project--the main application runs, but the debugger only hits breakpoints in the external dll. If I hit debug from the main project, the main application runs with the most recently built external dll, but now the debugger only hits breakpoints in the main project.

I realize one debugger will do the job for both, but I find it easier to keep the two straight this way.

[according to Martin Beckett, the guy who send me this answer ]

You can debug into an external library.

In the project settings tab look for 'visual studio directories' in the 'source code' field include the path to the openCV sources. Then make sure that the .pdb files for each of the debug dll are in the same directory as the dll.