這個問題一直困擾我許多，拜 Google 也拜不出來。而且文件上也載明
To attach to a running process
On the Debug menu, select Attach to Process. (If no project is open, select Attach to Process from the Tools menu.)
In the Attach to Process dialog box, find the program that you want to attach to from the Available Processes list.
結果…原來…
對，就是這麼簡單，但困擾我許久。