从辅助监视器捕获图像、裁剪和保存

Question

我正在尝试编写一个应用程序，该应用程序可以拍摄其中一个监视器上某个区域的屏幕截图并将其保存到图像中。屏幕截图应在给定宽度和高度的x，y坐标下拍摄。保存图像时，应将其保存在0,0和相同的宽度-高度。我在主显示器上有这个功能，但当我试图拍摄第二台或第三台显示器的屏幕截图时，它不起作用。我要么得到一个黑色的图像，要么打开一个文件后说它的格式无效。

我的代码是下面代码的修改版本，它拍摄了整个桌面的屏幕截图。https://github.com/GERD0GDU/dxgi_desktop_capture

主监视器宽度/高度2560 X 1440

主监视器上角x/y坐标为0,0，通过调用检索

POINT cursorPos;
GetCursorPos(&cursorPos);

辅助监视器宽度/高度1080 x 1920

辅助监视器上角x/y坐标为2560，-238

为了参考我在主监视器上工作的图像坐标，我正在通过x:801 y:227，宽度：1756，高度：1115

对于我的第二台显示器，它位于我的主显示器的右侧，并向侧面翻转，使其比宽更高，我正在通过x:2907 y：-11宽度：737高度：1595

HRESULT CDXGICapture::CaptureToFile(_In_ LPCWSTR lpcwOutputFileName, int x, int y, int width, int height)
{
AUTOLOCK();
if (!m_bInitialized) {
return D2DERR_NOT_INITIALIZED;
}
CHECK_POINTER_EX(m_ipDxgiOutputDuplication, E_INVALIDARG);
CHECK_POINTER_EX(lpcwOutputFileName, E_INVALIDARG);
HRESULT hr = S_OK;
hr = DXGICaptureHelper::IsRendererInfoValid(&m_rendererInfo);
if (FAILED(hr)) {
return hr;
}
// is valid?
hr = DXGICaptureHelper::GetContainerFormatByFileName(lpcwOutputFileName);
if (FAILED(hr)) {
return hr;
}
DXGI_OUTDUPL_FRAME_INFO     FrameInfo;
CComPtr<IDXGIResource>      ipDesktopResource;
CComPtr<ID3D11Texture2D>    ipAcquiredDesktopImage;
CComPtr<ID2D1Bitmap>        ipD2D1SourceBitmap;

// Get new frame
int lTryCount = 4;
do
{
Sleep(1);
hr = m_ipDxgiOutputDuplication->AcquireNextFrame(250, &FrameInfo, &ipDesktopResource);
if (SUCCEEDED(hr))
break;
if (hr == DXGI_ERROR_WAIT_TIMEOUT)
{
continue;
}
else if (FAILED(hr))
break;
} while (--lTryCount > 0);
if (hr == DXGI_ERROR_WAIT_TIMEOUT)
{
return S_FALSE;
}
else if (FAILED(hr))
{
return hr;
}
// QI for ID3D11Texture2D
hr = ipDesktopResource->QueryInterface(IID_PPV_ARGS(&ipAcquiredDesktopImage));
ipDesktopResource = nullptr;
CHECK_HR_RETURN(hr);
if (nullptr == ipAcquiredDesktopImage)
{
// release frame
m_ipDxgiOutputDuplication->ReleaseFrame();
return E_OUTOFMEMORY;
}
// Copy needed full part of desktop image
m_ipD3D11DeviceContext->CopyResource(m_ipCopyTexture2D, ipAcquiredDesktopImage);
// release frame
hr = m_ipDxgiOutputDuplication->ReleaseFrame();
CHECK_HR_RETURN(hr);

// create D2D1 source bitmap
hr = DXGICaptureHelper::CreateBitmap(m_ipD2D1RenderTarget, m_ipCopyTexture2D, &ipD2D1SourceBitmap);
CHECK_HR_RETURN(hr);
//try this
D2D1_RECT_F rcSource = D2D1::RectF(
(FLOAT)x,
(FLOAT)y,
(FLOAT)x + width,
(FLOAT)y+ height);

D2D1_RECT_F rcTarget = D2D1::RectF(
(FLOAT)0,
(FLOAT)0,
(FLOAT)width,
(FLOAT)height);

D2D1_POINT_2F ptTransformCenter = D2D1::Point2F(width / 2.0f, height / 2.0f);
// Apply the rotation transform to the render target.
D2D1::Matrix3x2F rotate = D2D1::Matrix3x2F::Rotation(
m_rendererInfo.RotationDegrees,
ptTransformCenter
);
D2D1::Matrix3x2F scale = D2D1::Matrix3x2F::Scale(
D2D1::SizeF(1, 1),
ptTransformCenter
);
// Priority: first rotate, after scale...
m_ipD2D1RenderTarget->SetTransform(rotate * scale);
m_ipD2D1RenderTarget->BeginDraw();
// clear background color
m_ipD2D1RenderTarget->Clear(D2D1::ColorF(D2D1::ColorF::White, 1.0f));
m_ipD2D1RenderTarget->DrawBitmap(ipD2D1SourceBitmap, rcTarget, 1.0f, D2D1_BITMAP_INTERPOLATION_MODE_LINEAR, rcSource);
//m_ipD2D1RenderTarget->SetTransform(D2D1::Matrix3x2F::Identity());
hr = m_ipD2D1RenderTarget->EndDraw();
if (FAILED(hr)) {
return hr;
}
hr = DXGICaptureHelper::SaveImageToFile(m_ipWICImageFactory, m_ipWICOutputBitmap, lpcwOutputFileName, width, height);
if (FAILED(hr)) {
return hr;
}
return S_OK;
} // CaptureToFile

我的保存到文件方法

static
COM_DECLSPEC_NOTHROW
inline
HRESULT
SaveImageToFile(
_In_ IWICImagingFactory* pWICImagingFactory,
_In_ IWICBitmapSource* pWICBitmapSource,
_In_ LPCWSTR lpcwFileName,
_In_ unsigned int uiWidth,
_In_ unsigned int uiHeight
)
{
CHECK_POINTER_EX(pWICImagingFactory, E_INVALIDARG);
CHECK_POINTER_EX(pWICBitmapSource, E_INVALIDARG);
HRESULT hr = S_OK;
GUID guidContainerFormat;
hr = GetContainerFormatByFileName(lpcwFileName, &guidContainerFormat);
if (FAILED(hr)) {
return hr;
}
WICPixelFormatGUID format = GUID_WICPixelFormatDontCare;
CComPtr<IWICImagingFactory> ipWICImagingFactory(pWICImagingFactory);
CComPtr<IWICBitmapSource> ipWICBitmapSource(pWICBitmapSource);
CComPtr<IWICStream> ipStream;
CComPtr<IWICBitmapEncoder> ipEncoder;
CComPtr<IWICBitmapFrameEncode> ipFrameEncode;
//  unsigned int uiWidth = 1756;
//  unsigned int uiHeight = 1115;
hr = ipWICImagingFactory->CreateStream(&ipStream);
if (SUCCEEDED(hr)) {
hr = ipStream->InitializeFromFilename(lpcwFileName, GENERIC_WRITE);
}
if (SUCCEEDED(hr)) {
hr = ipWICImagingFactory->CreateEncoder(guidContainerFormat, NULL, &ipEncoder);
}
if (SUCCEEDED(hr))
{
hr = ipEncoder->Initialize(ipStream, WICBitmapEncoderNoCache);
}
if (SUCCEEDED(hr))
{
hr = ipEncoder->CreateNewFrame(&ipFrameEncode, NULL);
}
if (SUCCEEDED(hr))
{
hr = ipFrameEncode->Initialize(NULL);
}
if (SUCCEEDED(hr))
{
hr = ipFrameEncode->SetSize(uiWidth, uiHeight);
}
if (SUCCEEDED(hr))
{
hr = ipFrameEncode->SetPixelFormat(&format);
}
if (SUCCEEDED(hr))
{
hr = ipFrameEncode->WriteSource(ipWICBitmapSource, NULL);
}
if (SUCCEEDED(hr))
{
hr = ipFrameEncode->Commit();
}
if (SUCCEEDED(hr))
{
hr = ipEncoder->Commit();
}
return hr;
} // SaveImageToFile

Answer 1

传入的坐标需要在不考虑其他监视器的情况下自行规范化到监视器。IE从监视器左上角的0,0开始，所有x和y值都需要为正。

为了获得监视器的坐标，我使用了以下内容，其中Control是我试图在应用程序中捕获的视图。

Monitor[] monitors = Display.getDefault().getMonitors();
Control control = getScreenCaptureControlArea();
Point p = control.toDisplay(0, 0);
for (Monitor monitor : monitors) {
Rectangle bounds = monitor.getBounds();
if (monitor.getBounds().contains(p.x, p.y)) {
setxCord(Math.abs(Math.abs(bounds.x) - Math.abs(p.x)));
setyCord(Math.abs(Math.abs(bounds.y) - Math.abs(p.y)));
setWidth(control.getSize().x);
setHeight(control.getSize().y);
break;
}
}

请注意，当显示器处于人像模式时，这仍然不起作用，因为保存的图像不正确。但由于我的应用程序不打算在纵向模式下使用，所以这无关紧要，所以我没有花更多的精力来解决这个问题。