一个简单的win32截图例子

#include "SaveBitmapToFile.cpp"
#include <windows.h>
#define  IDC_SAVE 1
#define  IDC_FILEPATH 2

LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam) ;

void InitWindow(HWND hWnd, LPARAM lParam);

int WINAPI WinMain( HINSTANCE hInstance, HINSTANCE hPrevInstance,
PSTR szCmdLine, int iCmdShow)
{
static TCHAR szAppName[] = TEXT ("test") ;

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 ("注册窗口类失败！"), szAppName, MB_ICONERROR) ;
return 0 ;
}

hWnd = CreateWindow (szAppName,
TEXT ("test"),
WS_OVERLAPPEDWINDOW,
100,
100,
350,
100,
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)
{
HDC         hdc ;
PAINTSTRUCT ps;
HBITMAP        hBitmap;
HDC            hdcMem;
static int screenx, screeny;
static char filePath[MAXPNAMELEN];

switch (message)
{
case WM_PAINT:
hdc = BeginPaint(hWnd, &ps);
EndPaint(hWnd,&ps);
return 0;

case WM_CREATE:
InitWindow(hWnd, lParam);
screenx = GetSystemMetrics(SM_CXSCREEN);
screeny = GetSystemMetrics(SM_CYSCREEN);
return 0;

case WM_COMMAND:

switch (LOWORD(wParam))
{
case IDC_SAVE:
GetDlgItemText(hWnd, IDC_FILEPATH, (LPWSTR)filePath, sizeof(filePath));

ShowWindow(hWnd, SW_HIDE);
Sleep(500);

hdc = GetDC(NULL);

hBitmap = CreateCompatibleBitmap(hdc, screenx, screeny);
hdcMem = CreateCompatibleDC(hdc);

SelectObject(hdcMem, hBitmap);
BitBlt(hdcMem, 0, 0, screenx, screeny, hdc, 0, 0, SRCCOPY);
SaveBitmapToFile((LPCTSTR)filePath, hdc, hBitmap);

ReleaseDC(hWnd, hdcMem);
ReleaseDC(hWnd, hdc);

ShowWindow(hWnd, SW_SHOW);

MessageBox(hWnd, TEXT("截图完成"), TEXT("提示"), MB_OK);
return 0;
}

return 0;

case WM_DESTROY:
PostQuitMessage (0) ;
return 0 ;
}

return DefWindowProc (hWnd, message, wParam, lParam) ;
}

void InitWindow(HWND hWnd, LPARAM lParam)
{
HWND btnSave, txtFilePath;

btnSave = CreateWindow(TEXT("BUTTON"),
TEXT("Save"),
WS_CHILD | BS_PUSHBUTTON,
20,
30,
100,
25,
hWnd,
(HMENU)IDC_SAVE,
((LPCREATESTRUCT) lParam)->hInstance,
NULL);

txtFilePath = CreateWindow(TEXT("EDIT"),
TEXT("d:\\test.bmp"),
WS_CHILD | WS_BORDER,
20,
1,
300,
25,
hWnd,
(HMENU)IDC_FILEPATH,
((LPCREATESTRUCT) lParam)->hInstance,
NULL);

ShowWindow(btnSave, SW_SHOW);
ShowWindow(txtFilePath, SW_SHOW);
}