简单截屏

#define MICROSOFT_WINDOWS_WINBASE_H_DEFINE_INTERLOCKED_CPLUSPLUS_OVERLOADS 0

#include <windows.h>

int WINAPI WinMain(

   _In_ HINSTANCE hInstance,

   _In_opt_ HINSTANCE hPrevInstance,

   _In_ LPSTR lpCmdLine,

   _In_ int nCmdShow)

{

   // 获取主显示设备上下文

   HDC hdcScreen = GetDC(NULL);

   // 为屏幕截图创建一个兼容的设备上下文

   HDC hdcCompatible = CreateCompatibleDC(hdcScreen);

   // 获取主显示器的尺寸

   int width = GetDeviceCaps(hdcScreen, HORZRES);

   int height = GetDeviceCaps(hdcScreen, VERTRES);

   // 为截图创建一个位图

   HBITMAP hBitmap = CreateCompatibleBitmap(hdcScreen, width, height);

   // 选择位图到兼容的设备上下文中

   HGDIOBJ hOldBitmap = SelectObject(hdcCompatible, hBitmap);

   // 将主显示器的内容复制到兼容的设备上下文中

   BitBlt(hdcCompatible, 0, 0, width, height, hdcScreen, 0, 0, SRCCOPY);

   // 将原始位图恢复到兼容的设备上下文中

   SelectObject(hdcCompatible, hOldBitmap);

   // 释放兼容的设备上下文

   DeleteDC(hdcCompatible);

   // 释放主显示设备上下文

   ReleaseDC(NULL, hdcScreen);

   // 将截图保存到文件中

   HANDLE hFile = CreateFile(TEXT("screenshot.bmp"), GENERIC_WRITE, 0, NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);

   BITMAPFILEHEADER bfh;

   BITMAPINFOHEADER bih;

   DWORD dwBytesWritten;

   bfh.bfType = 0x4d42; // "BM"

   bfh.bfSize = sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER) + width * height * 4;

   bfh.bfReserved1 = 0;

   bfh.bfReserved2 = 0;

   bfh.bfOffBits = sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER);

   bih.biSize = sizeof(BITMAPINFOHEADER);

   bih.biWidth = width;

   bih.biHeight = height;

   bih.biPlanes = 1;

   bih.biBitCount = 32;

   bih.biCompression = BI_RGB;

   bih.biSizeImage = 0;

   bih.biXPelsPerMeter = 0;

   bih.biYPelsPerMeter = 0;

   bih.biClrUsed = 0;

   bih.biClrImportant = 0;

   WriteFile(hFile, &bfh, sizeof(BITMAPFILEHEADER), &dwBytesWritten, NULL);

   WriteFile(hFile, &bih, sizeof(BITMAPINFOHEADER), &dwBytesWritten, NULL);

   unsigned char* pData = (unsigned char*)malloc(width * height * 4);

   if (pData != NULL) {

       GetBitmapBits(hBitmap, width * height * 4, pData);

       WriteFile(hFile, pData, width * height * 4, &dwBytesWritten, NULL);

   }

   free(pData);

   CloseHandle(hFile);

   return 0;

}