屏幕截图

// ScreenCapture.cpp : 定义应用程序的入口点。
//

#include "stdafx.h"
#include "ScreenCapture.h"

#define MAX_LOADSTRING 100

// 全局变量:
HINSTANCE hInst;                                // 当前实例
TCHAR szTitle[MAX_LOADSTRING];                    // 标题栏文本
TCHAR szWindowClass[MAX_LOADSTRING];            // 主窗口类名

// 此代码模块中包含的函数的前向声明:
ATOM                MyRegisterClass(HINSTANCE hInstance);
BOOL                InitInstance(HINSTANCE, int);
LRESULT CALLBACK    WndProc(HWND, UINT, WPARAM, LPARAM);
INT_PTR CALLBACK    About(HWND, UINT, WPARAM, LPARAM);

HDC g_srcMemDc;
HDC g_grayMemDc;
int screenW;
int screenH;

RECT rect = { 0 };   //画图的矩形区域
bool isDrawing = false;
bool isSelect = false;

void GetScreenCapture();
void CovertToGrayBitmap(HBITMAP hSourceBmp, HDC sourceDc);
void WriteDatatoClipBoard();

int APIENTRY _tWinMain(_In_ HINSTANCE hInstance,
_In_opt_ HINSTANCE hPrevInstance,
_In_ LPTSTR    lpCmdLine,
_In_ int       nCmdShow)
{
UNREFERENCED_PARAMETER(hPrevInstance);
UNREFERENCED_PARAMETER(lpCmdLine);

// TODO: 在此放置代码。
MSG msg;
HACCEL hAccelTable;

// 初始化全局字符串
LoadString(hInstance, IDS_APP_TITLE, szTitle, MAX_LOADSTRING);
LoadString(hInstance, IDC_SCREENCAPTURE, szWindowClass, MAX_LOADSTRING);
MyRegisterClass(hInstance);

// 执行应用程序初始化:
if (!InitInstance(hInstance, nCmdShow))
{
return FALSE;
}

hAccelTable = LoadAccelerators(hInstance, MAKEINTRESOURCE(IDC_SCREENCAPTURE));

// 主消息循环:
while (GetMessage(&msg, NULL, 0, 0))
{
if (!TranslateAccelerator(msg.hwnd, hAccelTable, &msg))
{
TranslateMessage(&msg);
DispatchMessage(&msg);
}
}

return (int)msg.wParam;
}

//
//  函数: MyRegisterClass()
//
//  目的: 注册窗口类。
//
ATOM MyRegisterClass(HINSTANCE hInstance)
{
WNDCLASSEX wcex;

wcex.cbSize = sizeof(WNDCLASSEX);

wcex.style = CS_HREDRAW | CS_VREDRAW | CS_DBLCLKS;
wcex.lpfnWndProc = WndProc;
wcex.cbClsExtra = 0;
wcex.cbWndExtra = 0;
wcex.hInstance = hInstance;
wcex.hIcon = LoadIcon(hInstance, MAKEINTRESOURCE(IDI_SCREENCAPTURE));
wcex.hCursor = LoadCursor(NULL, IDC_ARROW);
wcex.hbrBackground = (HBRUSH)(COLOR_WINDOW + 1);
wcex.lpszMenuName = 0;//MAKEINTRESOURCE(IDC_SCREENCAPTURE);
wcex.lpszClassName = szWindowClass;
wcex.hIconSm = LoadIcon(wcex.hInstance, MAKEINTRESOURCE(IDI_SMALL));

return RegisterClassEx(&wcex);
}

//
//   函数: InitInstance(HINSTANCE, int)
//
//   目的: 保存实例句柄并创建主窗口
//
//   注释:
//
//        在此函数中，我们在全局变量中保存实例句柄并
//        创建和显示主程序窗口。
//
BOOL InitInstance(HINSTANCE hInstance, int nCmdShow)
{
HWND hWnd;

hInst = hInstance; // 将实例句柄存储在全局变量中

hWnd = CreateWindow(szWindowClass, szTitle, WS_POPUP,
CW_USEDEFAULT, 0, CW_USEDEFAULT, 0, NULL, NULL, hInstance, NULL);

if (!hWnd)
{
return FALSE;
}

ShowWindow(hWnd, SW_MAXIMIZE);
UpdateWindow(hWnd);

return TRUE;
}

//
//  函数: WndProc(HWND, UINT, WPARAM, LPARAM)
//
//  目的: 处理主窗口的消息。
//
//  WM_COMMAND    - 处理应用程序菜单
//  WM_PAINT    - 绘制主窗口
//  WM_DESTROY    - 发送退出消息并返回
//
//
LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
int wmId, wmEvent;
PAINTSTRUCT ps;
HDC hdc;

LOGBRUSH brush;
brush.lbStyle = BS_NULL;
HBRUSH hBrush = CreateBrushIndirect(&brush);

LOGPEN pen;
POINT penWidth;
penWidth.x = 2;
penWidth.y = 2;
pen.lopnColor = 0x0000FFFF;
pen.lopnStyle = PS_SOLID;
pen.lopnWidth = penWidth;
HPEN hPen = CreatePenIndirect(&pen);

switch (message)
{
case WM_COMMAND:
wmId = LOWORD(wParam);
wmEvent = HIWORD(wParam);
// 分析菜单选择:
switch (wmId)
{
case IDM_ABOUT:
DialogBox(hInst, MAKEINTRESOURCE(IDD_ABOUTBOX), hWnd, About);
break;
case IDM_EXIT:
DestroyWindow(hWnd);
break;
default:
return DefWindowProc(hWnd, message, wParam, lParam);
}
break;

case WM_CREATE:
GetScreenCapture();
break;
case WM_PAINT:
{
hdc = BeginPaint(hWnd, &ps);

HDC memDc = CreateCompatibleDC(hdc);
HBITMAP bmp = CreateCompatibleBitmap(hdc, screenW, screenH);
SelectObject(memDc, bmp);

BitBlt(memDc, 0, 0, screenW, screenH, g_grayMemDc, 0, 0, SRCCOPY);
SelectObject(memDc, hBrush);
SelectObject(memDc, hPen);

if (isDrawing || isSelect)
{

BitBlt(memDc, rect.left, rect.top, rect.right - rect.left, rect.bottom - rect.top, g_srcMemDc, rect.left, rect.top, SRCCOPY);
Rectangle(memDc, rect.left, rect.top, rect.right, rect.bottom);
}

BitBlt(hdc, 0, 0, screenW, screenH, memDc, 0, 0, SRCCOPY);

DeleteObject(bmp);
DeleteObject(memDc);

EndPaint(hWnd, &ps);
}
break;

case WM_LBUTTONDOWN:
{
if (!isSelect)
{
POINT pt;
GetCursorPos(&pt);
rect.left = pt.x;
rect.top = pt.y;
rect.right = pt.x;
rect.bottom = pt.y;

isDrawing = true;
InvalidateRgn(hWnd, 0, false);
}
}
break;

case WM_LBUTTONUP:
{
if (isDrawing && !isSelect)
{
isDrawing = false;
POINT pt;
GetCursorPos(&pt);
rect.right = pt.x;
rect.bottom = pt.y;

isSelect = true;

InvalidateRgn(hWnd, 0, false);
}
}
break;

case WM_MOUSEMOVE:
{
if (isDrawing&& !isSelect)
{
POINT pt;
GetCursorPos(&pt);
rect.right = pt.x;
rect.bottom = pt.y;
InvalidateRgn(hWnd, 0, false);
}
}
break;
case WM_LBUTTONDBLCLK:
{
if (isSelect)
{
WriteDatatoClipBoard();
InvalidateRgn(hWnd, 0, false);
ShowWindow(hWnd, SW_MINIMIZE);
}
isSelect = false;

}
break;
case WM_DESTROY:
PostQuitMessage(0);
break;
default:
return DefWindowProc(hWnd, message, wParam, lParam);
}
return 0;
}

// “关于”框的消息处理程序。
INT_PTR CALLBACK About(HWND hDlg, UINT message, WPARAM wParam, LPARAM lParam)
{
UNREFERENCED_PARAMETER(lParam);
switch (message)
{
case WM_INITDIALOG:
return (INT_PTR)TRUE;

case WM_COMMAND:
if (LOWORD(wParam) == IDOK || LOWORD(wParam) == IDCANCEL)
{
EndDialog(hDlg, LOWORD(wParam));
return (INT_PTR)TRUE;
}
break;
}
return (INT_PTR)FALSE;
}

void GetScreenCapture()
{
HDC disDc = ::CreateDC(L"DISPLAY", 0, 0, 0);  //创建屏幕相关的DC
screenW = GetDeviceCaps(disDc, HORZRES);//水平分辨率
screenH = GetDeviceCaps(disDc, VERTRES);//垂直分辨率

g_srcMemDc = CreateCompatibleDC(disDc);  //创建于屏幕兼容的DC（内存DC）
HBITMAP hbMap = CreateCompatibleBitmap(disDc, screenW, screenH);  //模拟一张画布，其中是没有数据的
SelectObject(g_srcMemDc, hbMap);   //将画图选入内存DC，其中还是没有数据的
BitBlt(g_srcMemDc, 0, 0, screenW, screenH, disDc, 0, 0, SRCCOPY);  //将屏幕的dc中的画图，拷贝至内存DC中

//获取屏幕的灰度图片
g_grayMemDc = CreateCompatibleDC(disDc);
HBITMAP grayMap = CreateCompatibleBitmap(disDc, screenW, screenH);  //模拟一张画布，其中是没有数据的
SelectObject(g_grayMemDc, grayMap);   //将画图选入内存DC，其中还是没有数据的
BitBlt(g_grayMemDc, 0, 0, screenW, screenH, disDc, 0, 0, SRCCOPY);  //将屏幕的dc中的画图，拷贝至内存DC中

CovertToGrayBitmap(grayMap, g_grayMemDc);  //将彩色图片转换灰度图片

DeleteObject(hbMap);
DeleteObject(grayMap);
DeleteObject(disDc);
}

void CovertToGrayBitmap(HBITMAP hSourceBmp, HDC sourceDc)
{
HBITMAP retBmp = hSourceBmp;
BITMAPINFO bmpInfo;
ZeroMemory(&bmpInfo, sizeof(BITMAPINFO));
bmpInfo.bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
GetDIBits(sourceDc, retBmp, 0, 0, NULL, &bmpInfo, DIB_RGB_COLORS);

BYTE* bits = new BYTE[bmpInfo.bmiHeader.biSizeImage];
GetBitmapBits(retBmp, bmpInfo.bmiHeader.biSizeImage, bits);

int bytePerPixel = 4;//默认32位
if (bmpInfo.bmiHeader.biBitCount == 24)
{
bytePerPixel = 3;
}
for (DWORD i = 0; i < bmpInfo.bmiHeader.biSizeImage; i += bytePerPixel)
{
BYTE r = *(bits + i);
BYTE g = *(bits + i + 1);
BYTE b = *(bits + i + 2);
*(bits + i) = *(bits + i + 1) = *(bits + i + 2) = (r + b + g) / 3;
}
SetBitmapBits(hSourceBmp, bmpInfo.bmiHeader.biSizeImage, bits);
delete[] bits;
}

void WriteDatatoClipBoard()
{
HDC hMemDc, hScrDc;
HBITMAP hBmp, hOldBmp;
int width, height;
width = rect.right - rect.left;
height = rect.bottom - rect.top;

hScrDc = CreateDC(L"DISPLAY", NULL, NULL, NULL);
hMemDc = CreateCompatibleDC(hScrDc);
hBmp = CreateCompatibleBitmap(hScrDc, width, height);

hOldBmp = (HBITMAP)SelectObject(hMemDc, hBmp);
BitBlt(hMemDc, 0, 0, width, height, g_srcMemDc, rect.left, rect.top, SRCCOPY);
hBmp = (HBITMAP)SelectObject(hMemDc, hOldBmp);
DeleteDC(hMemDc);
DeleteDC(hScrDc);
//复制到剪贴板
if (OpenClipboard(0))
{
EmptyClipboard();
SetClipboardData(CF_BITMAP, hBmp);
CloseClipboard();
}

DeleteObject(hBmp);
DeleteObject(hMemDc);
DeleteObject(hScrDc);

}