为什么 GetWindowLongPtr(GetConsoleWindow(),GWL_WNDPROC) 返回 NULL？

[usercsdn_1]

是没有权限访问窗口例程吗？

[an_bachelor]

可以看看GetLastError()返回什么

[Eleven]

Console窗口程序是关联到了Windows的Conhost.exe应用。 Calling SetWindowLongPtr with the GWLP_WNDPROC index creates a subclass of the window class used to create the window. An application can subclass a system class, but should not subclass a window class created by another process. The SetWindowLongPtr function creates the window subclass by changing the window procedure associated with a particular window class, causing the system to call the new window procedure instead of the previous one. An application must pass any messages not processed by the new window procedure to the previous window procedure by calling CallWindowProc. This allows the application to create a chain of window procedures.

[Minikinfish]

An application can subclass a system class, but should not subclass a window class created by another process