问题
I have a GUI program that opens a Windows console in a separate window to display output and accept user input. My development environment is Qt 4.7.1 with mingw. The console works fine, until I try to run the program in Qt's debugger (gdb); then, although AllocConsole succeeds, and GetStdHandle appears to return a valid handle (0x000000d8), any attempt to use the handle causes Windows error 6 (invalid handle).
So I can't debug my program. Which is a pain, because it has some serious bugs. The problem may be that gdb's console prevents me opening my own console; but then why do AllocConsole and GetStdHandle succeed? I upgraded to Qt Creator 2.0.94 (Qt 4.7.1), but it didn't help. Any ideas?
Update I have found that I can debug the program by running it without the debugger, and then attaching to it from Qt. Not ideal, but better than nothing.
回答1:
Can't you use the standard output console, using CONFIG += console in the .pro file?
Hmm -- check this out:
A process can be associated with only one console, so the AllocConsole function fails if the calling process already has a console. A process can use the FreeConsole function to detach itself from its current console, then it can call AllocConsole to create a new console or AttachConsole to attach to another console.
Can you try running FreeConsole before you create yours?
来源：https://stackoverflow.com/questions/4868411/gui-program-cant-allocate-a-console-in-qts-debugger