示例程序：
#include <windows.h>
#define DIVISIONS 5
LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM) ;
LRESULT CALLBACK ChildWndProc(HWND, UINT, WPARAM, LPARAM) ;
TCHAR szChildClass[] = TEXT ("Checker3_Child") ;
int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,PSTR szCmdLine, int iCmdShow)
{
static TCHAR szAppName[] = TEXT ("Checker3") ;
HWND hwnd ;
MSG msg ;
WNDCLASS wndclass ;
wndclass.style = CS_HREDRAW | CS_VREDRAW ;
wndclass.lpfnWndProc = WndProc ;
wndclass.cbClsExtra = 0 ;
wndclass.cbWndExtra = 0 ;
wndclass.hInstance = hInstance ;
wndclass.hIcon = LoadIcon (NULL, IDI_APPLICATION) ;
wndclass.hCursor = LoadCursor (NULL, IDC_ARROW) ;
wndclass.hbrBackground = (HBRUSH) GetStockObject (WHITE_BRUSH) ;
wndclass.lpszMenuName = NULL ;
wndclass.lpszClassName = szAppName ;// 通过ClassName来标志注册的窗口，创建的时候也用它
if (!RegisterClass (&wndclass))
{
MessageBox ( NULL, TEXT ("Program requires Windows NT!"),szAppName, MB_ICONERROR) ;
return 0 ;
}
wndclass.lpfnWndProc = ChildWndProc ;
wndclass.cbWndExtra = sizeof (long) + 3 ;
wndclass.hIcon = NULL ;
wndclass.lpszClassName = szChildClass ;
RegisterClass (&wndclass) ;
hwnd = CreateWindow(szAppName, TEXT ("Checker3 Mouse Hit-Test Demo"),WS_OVERLAPPEDWINDOW,
CW_USEDEFAULT, CW_USEDEFAULT,CW_USEDEFAULT, CW_USEDEFAULT,
NULL, NULL, hInstance, NULL) ;
ShowWindow(hwnd, iCmdShow) ;
UpdateWindow(hwnd) ;
while (GetMessage (&msg, NULL, 0, 0))
{
TranslateMessage (&msg) ;
DispatchMessage (&msg) ;
}
return msg.wParam ;
}
LRESULT CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wParam,LPARAM lParam)
{
static HWND hwndChild[DIVISIONS][DIVISIONS] ;
int cxBlock, cyBlock, x, y ;
switch (message)
{
case WM_CREATE :
for (x = 0 ; x < DIVISIONS ; x++)
for (y = 0 ; y < DIVISIONS ; y++)
//GetWindowLong根据窗口句柄来获取窗口相关的信息
//hMenu变量或者为menu句柄，或者为子窗口ID
hwndChild[x][y] = CreateWindow (szChildClass, NULL,WS_CHILDWINDOW | WS_VISIBLE,
0, 0, 0, 0,hwnd, (HMENU)(y << 8 | x),(HINSTANCE)GetWindowLong(hwnd, GWL_HINSTANCE),NULL);
return 0 ;
case WM_SIZE :
cxBlock = LOWORD (lParam) / DIVISIONS ;
cyBlock = HIWORD (lParam) / DIVISIONS ;
for (x = 0 ; x < DIVISIONS ; x++)
for (y = 0 ; y < DIVISIONS ; y++)
MoveWindow( hwndChild[x][y], x * cxBlock, y * cyBlock,cxBlock, cyBlock, TRUE);
return 0 ;
case WM_LBUTTONDOWN :
MessageBeep (0) ;
return 0 ;
case WM_DESTROY :
PostQuitMessage (0) ;
return 0 ;
}
return DefWindowProc (hwnd, message, wParam, lParam) ;
}
LRESULT CALLBACK ChildWndProc(HWND hwnd, UINT message,WPARAM wParam, LPARAM lParam)
{
HDC hdc ;
PAINTSTRUCT ps ;
RECT rect ;
int nTest;
switch (message)
{
case WM_CREATE:
SetWindowLong(hwnd, 0, 0) ; // on/off flag
return 0 ;
case WM_LBUTTONDOWN :
SetWindowLong (hwnd, 0, 1 ^ GetWindowLong (hwnd, 0)) ;
nTest = GetWindowLong(hwnd,100);
SetWindowLong(hwnd,100,0);
InvalidateRect (hwnd, NULL, FALSE) ;
return 0 ;
case WM_PAINT :
hdc = BeginPaint (hwnd, &ps) ;
GetClientRect (hwnd, &rect) ;
Rectangle (hdc, 0, 0, rect.right, rect.bottom) ;
if (GetWindowLong (hwnd, 0))
{
MoveToEx (hdc, 0, 0, NULL) ;
LineTo (hdc, rect.right, rect.bottom) ;
MoveToEx (hdc, 0, rect.bottom, NULL) ;
LineTo (hdc, rect.right, 0) ;
}
EndPaint (hwnd, &ps) ;
return 0 ;
}
return DefWindowProc (hwnd, message, wParam, lParam) ;
}
12 关于父窗口，子窗口消息传递的一些总结：
一个程序有父窗口，也有子窗口的时候，如果没有特别设置，那么初始化的时候焦点是在父窗口，如果要改变窗口焦点到子窗口那么可以直接在子窗口上点击鼠标，或者在程序中通过SetFocus（hwnd，childId）来设置。
总之：鼠标可以直接改变焦点，键盘不能直接改变焦点。
实例程序如下：
#include <windows.h>
#define DIVISIONS 5
LRESULT CALLBACK WndProc (HWND, UINT, WPARAM, LPARAM) ;
LRESULT CALLBACK ChildWndProc (HWND, UINT, WPARAM, LPARAM) ;
int idFocus = 0 ;
TCHAR szChildClass[] = TEXT ("Checker4_Child") ;
int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,PSTR szCmdLine, int iCmdShow)
{
static TCHAR szAppName[] = TEXT ("Checker4") ;
HWND hwnd ;
MSG msg ;
WNDCLASS wndclass ;
wndclass.style = CS_HREDRAW | CS_VREDRAW ;
wndclass.lpfnWndProc = WndProc ;
wndclass.cbClsExtra = 0 ;
wndclass.cbWndExtra = 0 ;
wndclass.hInstance = hInstance ;
wndclass.hIcon = LoadIcon (NULL, IDI_APPLICATION) ;
wndclass.hCursor = LoadCursor (NULL, IDC_ARROW) ;
wndclass.hbrBackground = (HBRUSH) GetStockObject (WHITE_BRUSH) ;
wndclass.lpszMenuName = NULL ;
wndclass.lpszClassName = szAppName ;
if (!RegisterClass (&wndclass))
{
MessageBox (NULL, TEXT ("Program requires Windows NT!"),szAppName, MB_ICONERROR) ;
return 0 ;
}
wndclass.lpfnWndProc = ChildWndProc ;
wndclass.cbWndExtra = sizeof (long) ;
wndclass.hIcon = NULL ;
wndclass.lpszClassName = szChildClass ;
RegisterClass (&wndclass) ;
hwnd = CreateWindow (szAppName, TEXT ("Checker4 Mouse Hit-Test Demo"),WS_OVERLAPPEDWINDOW,
CW_USEDEFAULT, CW_USEDEFAULT,CW_USEDEFAULT, CW_USEDEFAULT,
NULL, NULL, hInstance, NULL) ;
ShowWindow (hwnd, iCmdShow) ;
UpdateWindow (hwnd) ;
while (GetMessage (&msg, NULL, 0, 0))
{
TranslateMessage (&msg) ;
DispatchMessage (&msg) ;
}
return msg.wParam ;
}
LRESULT CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wParam,LPARAM lParam)
{
static HWND hwndChild[DIVISIONS][DIVISIONS] ;
int cxBlock, cyBlock, x, y ;
switch (message)
{
case WM_CREATE :
for (x = 0 ; x < DIVISIONS ; x++)
for (y = 0 ; y < DIVISIONS ; y++)
hwndChild[x][y] = CreateWindow (szChildClass, NULL,WS_CHILDWINDOW | WS_VISIBLE,
0, 0, 0, 0,hwnd, (HMENU) (y << 8 | x),(HINSTANCE) GetWindowLong(hwnd, GWL_HINSTANCE),NULL) ;
return 0 ;
case WM_SIZE :
cxBlock = LOWORD (lParam) / DIVISIONS ;
cyBlock = HIWORD (lParam) / DIVISIONS ;
for (x = 0 ; x < DIVISIONS ; x++)
for (y = 0 ; y < DIVISIONS ; y++)
MoveWindow ( hwndChild[x][y], x * cxBlock, y * cyBlock, cxBlock, cyBlock, TRUE) ;
return 0 ;
case WM_LBUTTONDOWN :
MessageBeep (0) ;
return 0 ;
// On set-focus message, set focus to child window
case WM_SETFOCUS:
//SetFocus (GetDlgItem (hwnd, idFocus)) ;
return 0 ;
// On key-down message, possibly change the focus window
case WM_KEYDOWN:
x = idFocus & 0xFF ;
y = idFocus >> 8 ;
switch (wParam)
{
case VK_UP:
y-- ; break ;
case VK_DOWN:
y++ ; break ;
case VK_LEFT:
x-- ; break ;
case VK_RIGHT:
x++ ; break ;
case VK_HOME:
x = y = 0 ;break ;
case VK_END:
x = y = DIVISIONS - 1 ; break ;
default: return 0 ;
}
x = (x + DIVISIONS) % DIVISIONS ;
y = (y + DIVISIONS) % DIVISIONS ;
idFocus = y << 8 | x ;
SetFocus (GetDlgItem (hwnd, idFocus)) ;
return 0 ;
case WM_DESTROY :
PostQuitMessage (0) ;
return 0 ;
}
return DefWindowProc (hwnd, message, wParam, lParam) ;
}
LRESULT CALLBACK ChildWndProc (HWND hwnd, UINT message,WPARAM wParam, LPARAM lParam)
{
HDC hdc ;
PAINTSTRUCT ps ;
RECT rect ;
switch (message)
{
case WM_CREATE :
SetWindowLong (hwnd, 0, 0) ; // on/off flag
return 0 ;
case WM_KEYDOWN:
// Send most key presses to the parent window
if (wParam != VK_RETURN && wParam != VK_SPACE)
{
SendMessage (GetParent (hwnd), message, wParam, lParam) ;
return 0 ;
}
// For Return and Space, fall through to toggle the square
case WM_LBUTTONDOWN :
SetWindowLong (hwnd, 0, 1 ^ GetWindowLong (hwnd, 0)) ;
SetFocus (hwnd) ;
InvalidateRect (hwnd, NULL, FALSE) ;
return 0 ;
// For focus messages, invalidate the window for repaint
case WM_SETFOCUS:
//鼠标点击，按键移动都会触发此消息，但是当鼠标单击时候idFocus没有变化，所以这里要对其赋值。
idFocus = GetWindowLong (hwnd, GWL_ID) ;
InvalidateRect (hwnd, NULL, TRUE) ;
break;
// Fall through
case WM_KILLFOCUS:
InvalidateRect (hwnd, NULL, TRUE) ;
return 0 ;
case WM_PAINT :
hdc = BeginPaint (hwnd, &ps) ;
GetClientRect (hwnd, &rect) ;
Rectangle (hdc, 0, 0, rect.right, rect.bottom) ;
// Draw the "x" mark
if (GetWindowLong (hwnd, 0))
{
MoveToEx (hdc, 0, 0, NULL) ;
LineTo (hdc, rect.right, rect.bottom) ;
MoveToEx (hdc, 0, rect.bottom, NULL) ;
LineTo (hdc, rect.right, 0) ;
}
// Draw the "focus" rectangle
if (hwnd == GetFocus ())
{
rect.left += rect.right / 10 ;
rect.right -= rect.left ;
rect.top += rect.bottom / 10 ;
rect.bottom -= rect.top ;
SelectObject (hdc, GetStockObject (NULL_BRUSH)) ;
SelectObject (hdc, CreatePen (PS_DASH, 0, 0)) ;
Rectangle (hdc, rect.left, rect.top, rect.right, rect.bottom) ;
DeleteObject (SelectObject (hdc, GetStockObject (BLACK_PEN))) ;
}
EndPaint (hwnd, &ps) ;
return 0 ;
}
return DefWindowProc (hwnd, message, wParam, lParam) ;
}
（1）
子窗口过程函数中有对WM_SETFOCUS消息的处理--
idFocus = GetWindowLong (hwnd, GWL_ID) ;这个消息处理对通过按键移动来改变窗口焦点的子窗口来说是多余的，但是对于通过鼠标单击改变焦点的子窗口说是必须的，所以就加了这么一句
（2）
子窗口过程函数中针对WM_SETFOCUS的消息处理
InvalidateRect (hwnd, NULL, TRUE) ; break;这两句在源程序中是没有的，一般针对case语句要加上break表示结束当前case，但是源程序没有加break，这样做是有道理的，原因：当通过按键改变窗口焦点的时候，需要重绘，但是源程序没有InvalidateRect的语句，所以基本焦点改变了，但是在焦点窗口中并没有重绘，这里没有break所以会把case WM_KILLFOCUS中的InvalidateRect执行，从而实现了对焦点窗口的重绘。
如果非要加break，那么就得在break前面再加一个InvalidateRect（）函数了，如现在的程序所示。
windows编程之鼠标消息总结,布布扣,bubuko.com
原文：http://blog.csdn.net/ddupd/article/details/23614029