Question

我正在尝试制作一个程序，用于制作整个桌面或特定窗口的屏幕截图，并在SFML窗口中绘制。最初它很好，但10秒后它停止捕获。我还注意到，即使我们只谈到每秒20kb的速度，它也会消耗RAM。我试图加入在网络上找到的代码。当它停止工作时，它打印“2”然后无限“1”，从代码中你很快意识到这些错误的位置。

#include <SFML/Graphics.hpp>
#include <Windows.h>

 HBITMAP ScreenShot(HWND hParent, int x, int y, int nWidth, int nHeight)
    {
//Get a DC from the parent window
    HDC hDC = GetDC(hParent);

//Create a memory DC to store the picture to
HDC hMemDC = CreateCompatibleDC(hDC);

//Create the actual picture
HBITMAP hBackground = CreateCompatibleBitmap(hDC, nWidth, nHeight);

//Select the object and store what we got back
HBITMAP hOld = (HBITMAP)SelectObject(hMemDC, hBackground);

//Now do the actually painting into the MemDC (result will be in the selected object)
//Note: We ask to return on 0,0,Width,Height and take a blit from x,y
BitBlt(hMemDC, 0, 0, nWidth, nHeight, hDC, x, y, SRCCOPY);

//Restore the old bitmap (if any)
SelectObject(hMemDC, hOld);

//Release the DCs we created
ReleaseDC(hParent, hMemDC);
ReleaseDC(hParent, hDC);



//Return the picture (not a clean method, but you get the drill)
    return hBackground;


 }

bool SFMLLoadHBitmapAsImage(HBITMAP hBitmap, sf::Image *pPicture)
{
    HWND hParent = FindWindow(NULL, TEXT("Calculator"));
    //if (hParent == NULL)printf("%s", "w");
    //Create a DC to get hBitmap information
    HDC hDC = GetDC(hParent);

    //Create BITMAPINFO variable, set size 
    BITMAPINFO MyBMInfo = { 0 };
    MyBMInfo.bmiHeader.biSize = sizeof(MyBMInfo.bmiHeader);

    //Get the BITMAPINFO structure from the bitmap
    if (0 == GetDIBits(hDC, hBitmap, 0, 0, NULL, &MyBMInfo, DIB_RGB_COLORS))
    {
        printf("%s", "1");
        return false;
    }

    //Create the bitmap pixel array each element is [b,g,r]
    BYTE* lpPixels = new BYTE[MyBMInfo.bmiHeader.biSizeImage];

    //Setting up the structure of the buffer to be received
    MyBMInfo.bmiHeader.biCompression = BI_RGB;  // No-compression

    //Now get the actual data from the picture
    if (0 == GetDIBits(hDC, hBitmap, 0, MyBMInfo.bmiHeader.biHeight, (LPVOID)lpPixels, &MyBMInfo, DIB_RGB_COLORS))
    {
        printf("%s", "2");
        return false;
    }

    //Now create an array of SFML pixels we want to fill
    sf::Uint8 *lpPixelWithAlpha = new sf::Uint8[MyBMInfo.bmiHeader.biSizeImage +
        (MyBMInfo.bmiHeader.biSizeImage / 3) / 3]; //Add room for alpha

    //Loop through each pixel, with steps of four RGBA!
    for (int x = 0; x < MyBMInfo.bmiHeader.biSizeImage; x += 4)
    {
        lpPixelWithAlpha[x] = lpPixels[x + 2];    //lpPixels = r
        lpPixelWithAlpha[x + 1] = lpPixels[x + 1];    //lpPixels = g
        lpPixelWithAlpha[x + 2] = lpPixels[x];    //lpPixels = b
        lpPixelWithAlpha[x + 3] = 255;        //Nada alpha (just to adjust if you like)
    }

    //Remove old DIBsection
    delete[] lpPixels;

    //Load picture, now with correct pixels and alpha channel
    pPicture->create(MyBMInfo.bmiHeader.biWidth,
        MyBMInfo.bmiHeader.biHeight, lpPixelWithAlpha);


    //Remove the pixels with alphachannel
    delete[] lpPixelWithAlpha;

    //Release the DC
    ReleaseDC(hParent, hDC);//::GDW()

    //Notify ok!
    return true;
}

int main()
{
.....
hBitmap = ScreenShot(FindWindow(NULL, TEXT("Calculator")), 0, 0, 640, 400);

        SFMLLoadHBitmapAsImage(hBitmap, &picture);
.....
}

截图代码可以工作，但继续进行RAM和崩溃

0 个答案: