如何获得一个窗口，在C ++中的位图对象的屏幕截图？ [英] How to get screenshot of a window as bitmap object in C++?

问题描述

如何获得一个窗口，在C ++中的位图对象的屏幕截图？假设我已经有窗口句柄。 我也想知道是否有可能得到一个窗口的截图，当它在最小化状态

How to get screenshot of a window as bitmap object in C++? Supposed that I already have the window handle. And I want to know also whether it's possible to get the screenshot of a window when it's in minimized state?

C ++在这里是指VC ++与使用Windows XP +（WIN32）。

C++ here means VC++ with all the libraries associated with Windows XP+ (win32).

推荐答案

您应该调用PrintWindow API：

you should call the PrintWindow API:

void CScreenShotDlg::OnPaint()
{
    // device context for painting
    CPaintDC dc(this);

    // Get the window handle of calculator application.
    HWND hWnd = ::FindWindow( 0, _T( "Calculator" ));

    // Take screenshot.
    PrintWindow( hWnd,
                 dc.GetSafeHdc(),
                 0 );
}

看到这样一个问题：获取窗口截图的窗口API

如果您不使用MFC，这里的纯PrintWindow签名：

if you are not using MFC, here the pure PrintWindow signature:

BOOL PrintWindow(
    HWND hwnd,
    HDC hdcBlt,
    UINT nFlags
);

查看MSDN了解更多详情：<一href=\"http://msdn.microsoft.com/en-us/library/dd162869(v=vs.85).aspx\">http://msdn.microsoft.com/en-us/library/dd162869(v=vs.85).aspx

有关如何将其保存为位图asMatteo说取决于你使用的是实际的框架...

about how to save it as bitmap asMatteo said depends on the actual framework you are using...

编辑：

在原始这儿用完整的例子++

here full example in raw C++

#define _WIN32_WINNT    0x0501        //xp
#include <windows.h>

int main()
{ 
    RECT rc;
    HWND hwnd = FindWindow(TEXT("Notepad"), NULL);    //the window can't be min
    if (hwnd == NULL)
    {
        cout << "it can't find any 'note' window" << endl;
        return 0;
    }
    GetClientRect(hwnd, &rc);

    //create
    HDC hdcScreen = GetDC(NULL);
    HDC hdc = CreateCompatibleDC(hdcScreen);
    HBITMAP hbmp = CreateCompatibleBitmap(hdcScreen, 
        rc.right - rc.left, rc.bottom - rc.top);
    SelectObject(hdc, hbmp);

    //Print to memory hdc
    PrintWindow(hwnd, hdc, PW_CLIENTONLY);

    //copy to clipboard
    OpenClipboard(NULL);
    EmptyClipboard();
    SetClipboardData(CF_BITMAP, hbmp);
    CloseClipboard();

    //release
    DeleteDC(hdc);
    DeleteObject(hbmp);
    ReleaseDC(NULL, hdcScreen);

    cout << "success copy to clipboard, please paste it to the 'mspaint'" << endl;

    return 0;
}

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