WPF Pass the debugger on to a newly spawned process

Question

I have an application that spawns a new process. During development of the application, I would like to attach a debugger to the new process. Currently I can do that through Visual Studios Attach to Process functionality, but it's a pain to go back and attach it manually every single time when I need to test a minor change to the code.

Is it possible to spawn a new process using Process.Start and then attach any debuggers that are currently attached to the current process onto the new process?

I.E.:

Start Process1 with debugging enabled
Process1 starts Process2
Process1 attaches the debugger to Process2

@MikeCorcoran - how would you do the same thing if it was a C++ program spawned from a C# program? — DanCaveman, Oct 12 '18 at 03:46

score 4 · Accepted Answer · answered Jul 29 '13 at 19:05

Not a very clean solution, but you could do something like this:

In Process1, if you're running in Debug mode (Debugger.IsAttached), pass an argument to Process2 (e.g. process2.exe /debug)
In Process2, if the process is started with the /debug argument, attach the debugger from code (Debugger.Launch())

Robert Petz · Answer 2 · 2013-07-29T20:38:01.723

2

As an FYI to anyone else looking at this, here is the code implementation of Thomas Levesque's (accepted) answer:

Code

Launching app:

Process.Start(/** Path to assembly **/, System.Diagnostics.Debugger.IsAttached ? "/Debug" : "");

Target app:

if (Environment.GetCommandLineArgs().Contains("/Debug"))
    System.Diagnostics.Debugger.Launch();

This will cause most instances of Visual Studio to prompt you with this when the new process starts:

enter image description here

This is normal...just hit 'Yes, debug [assembly name]'. The next window will prompt you to choose the debugger to attach to, which usually defaults to the debugger that was orignaly used to launch the starting app

edited Jul 29 '13 at 20:38

answered Jul 29 '13 at 20:09

Robert Petz

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You could simplify the test in the target app: `if (Environment.GetCommandLineArgs().Contains("/Debug"))` – Thomas Levesque Jul 29 '13 at 20:28
agreed...I always do database queries with linq to entities so I always wind up falling back to FirstOrDefault checking the primary key property lol, gotta remember that it's not always necessary... – Robert Petz Jul 29 '13 at 20:39

WPF Pass the debugger on to a newly spawned process

2 Answers2