AboutGetMessage

At there, we can not catch WM_CLOSE

Author: lifeng1992

Diff for: 0x01/MsgA.cpp

@@ -0,0 +1,91 @@
+// A program use test function GetMessage
+// Use the program, we can catch WM_LBUTTONDOWN but can not catch WM_CLOSE
+#include <Windows.h>
+#include <WindowsX.h>
+#include <stdio.h>
+
+void CreateWindowsClass(WNDCLASSEX *pwinclass, HINSTANCE hInstance);
+
+// 2.创建WinProc
+LRESULT CALLBACK WinProc(HWND hWnd, UINT Msg, WPARAM wParam, LPARAM lParam);
+
+int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hprevinstance, LPSTR lpCmdline, INT nCmdshow){
+	WNDCLASSEX	winclass;
+	HWND		hwnd;
+	MSG			msg;
+
+	// 1.创建一个Windows类
+	CreateWindowsClass(&winclass, hInstance);
+	// 3.注册Windows类
+	if(!RegisterClassEx(&winclass)){
+		return 0;
+	}
+	// 4.创建窗口
+	hwnd = CreateWindowExW(NULL, TEXT("winclass-MsgA"), TEXT("Msg TestA"),
+		WS_OVERLAPPEDWINDOW | WS_VISIBLE,
+		0, 0, 480, 320, NULL, NULL, hInstance, NULL);
+	if(!hwnd){
+		return 0;
+	}
+
+	while(GetMessage(&msg, NULL, 0, 0)){
+		if(msg.message == WM_CLOSE){
+			MessageBoxA(NULL, "I catch WM_CLOSE!", "NULL", MB_OK);
+		}else if(msg.message == WM_LBUTTONDOWN){
+			MessageBoxA(NULL, "I catch other Message WM_LBUTTONDOWN!", "NULL", MB_OK);
+		}else{
+			;
+		}
+
+		TranslateMessage(&msg);
+		DispatchMessage(&msg);
+	}
+
+	return msg.wParam;
+}
+
+void CreateWindowsClass(WNDCLASSEX *pwinclass, HINSTANCE hInstance){
+	pwinclass->cbSize			= sizeof(WNDCLASSEX);
+	pwinclass->style			= CS_HREDRAW | CS_VREDRAW | CS_OWNDC | CS_DBLCLKS;
+	pwinclass->lpfnWndProc		= WinProc;
+	pwinclass->cbClsExtra		= 0;
+	pwinclass->cbWndExtra		= 0;
+	pwinclass->hInstance		= hInstance;
+	pwinclass->hIcon			= LoadIcon(NULL, IDI_APPLICATION);
+	pwinclass->hCursor			= LoadCursor(NULL, IDC_ARROW);
+	pwinclass->hbrBackground	= (HBRUSH)GetStockObject(BLACK_BRUSH);
+	pwinclass->lpszMenuName		= NULL;
+	pwinclass->lpszClassName	= TEXT("WinClass-MsgA");
+	pwinclass->hIconSm			= LoadIcon(NULL, IDI_APPLICATION);
+}
+
+LRESULT CALLBACK WinProc(HWND hWnd, UINT Msg, WPARAM wParam, LPARAM lParam){
+	PAINTSTRUCT ps;
+	HDC			hdc;
+
+	switch(Msg){
+		case WM_CREATE:{
+			return 0;
+		}break;
+
+		case WM_PAINT:{
+			hdc = BeginPaint(hWnd, &ps);
+			EndPaint(hWnd, &ps);
+			return 0;
+		}break;
+
+		case WM_CLOSE:{
+			;
+		}break;
+
+		case WM_DESTROY:{
+			PostQuitMessage(0);
+			return 0;
+			break;
+		}
+
+		default:break;
+	}
+
+	return DefWindowProc(hWnd, Msg, wParam, lParam);			  
+}