Why do I receive WM_SETFOCUS only once?

[linjie]

My program has a view inherit from CView,when it receive WM_SETFOCUS I want do something,but the view receive WM_SETFOCUS message only once when program starting.why? linjie

[David Crow]

linjie wrote: the view receive WM_SETFOCUS message only once when program starting. What are you using to verify this? I tried this and used Spy++ to see the messages. The application received multiple WM_SETFOCUS messages.

---

Five birds are sitting on a fence. Three of them decide to fly off. How many are left?

[vcplusplus]

Because CView has the focus of the OS. From MSDN Library ----------------- The WM_SETFOCUS message is sent to a window after it has gained the keyboard focus. The SetFocus function sends a WM_KILLFOCUS message to the window that loses the keyboard focus and a WM_SETFOCUS message to the window that receives the keyboard focus. It also activates either the window that receives the focus or the parent of the window that receives the focus. If a window is active but does not have the focus, any key pressed will produce the WM_SYSCHAR, WM_SYSKEYDOWN, or WM_SYSKEYUP message. If the VK_MENU key is also pressed, the lParam parameter of the message will have bit 30 set. Otherwise, the messages produced do not have this bit set. By using the AttachThreadInput function, a thread can attach its input processing to another thread. This allows a thread to call SetFocus to set the keyboard focus to a window associated with another thread's message queue.