ID2D1Bitmap / DrawBitmap不起作用 [英] ID2D1Bitmap/DrawBitmap not working

问题描述

大家好，&感谢您阅读本文。

Hi all, & Thanks for reading this.

我已经从流中创建了一个ID2D1Bitmap，但是当我尝试在屏幕上渲染ID2D1Bitmap时，我什么都没看到。变量"pPixels"表示变量"pPixels"。包含正确的数据，所以，直到这一切都是好的。你在我的代码中看到任何问题吗？

I have created a ID2D1Bitmap from a stream, but when I try to render that ID2D1Bitmap on the screen, I see nothing. The variable "pPixels" contain the correct data, so, until this point everything is Ok. Do you see any problem in my code?

非常感谢！

	void *pPixels = malloc(nScreenWidth * nScreenHeight * 4);

	::GetDIBits(hCaptureDC,
		hCaptureBitmap,
		0,
		nScreenHeight,
		pPixels,
		&bmi,
		DIB_RGB_COLORS);


	RECT rect;
	GetClientRect(&rect);

	D2D1_PIXEL_FORMAT pixelFormat = D2D1::PixelFormat(DXGI_FORMAT_B8G8R8A8_UNORM, D2D1_ALPHA_MODE_PREMULTIPLIED);
	UINT32 pitch = nScreenWidth * 4;
	D2D1_BITMAP_PROPERTIES d2dBitmapProps =
	{
		{
			DXGI_FORMAT_A8_UNORM,
			D2D1_ALPHA_MODE_PREMULTIPLIED
		}, 0, 0
	};


	HRESULT hr;
	hr = CreateDeviceResources();
	if (!SUCCEEDED(hr)) return;
	ASSERT(m_pD2DFactory != NULL && m_pDCRenderTarget != NULL && m_pGreenBrush != NULL);

	hr = m_pDCRenderTarget->BindDC(pDC->GetSafeHdc(), &rect);

	m_pDCRenderTarget->BeginDraw();

		m_pDCRenderTarget->CreateBitmap(D2D1::SizeU(nScreenWidth, nScreenHeight), (const void*)pPixels, pitch, d2dBitmapProps, &pBitmap); // pBitmap - global variable	(ID2D1Bitmap* pBitmap = NULL;)

		m_pRenderTarget->DrawBitmap(pBitmap, D2D1::RectF(0, 0, nScreenWidth, nScreenHeight));

	m_pDCRenderTarget->EndDraw();

这里是"CreateDeviceResources"

And here is "CreateDeviceResources"

HRESULT CDRAWIXView::CreateDeviceResources()
{
	HRESULT hr = S_OK;

	if (m_pD2DFactory == NULL) return E_FAIL;

	if (m_pDCRenderTarget == NULL)
	{
		D2D1_RENDER_TARGET_PROPERTIES props =
			D2D1::RenderTargetProperties(
			D2D1_RENDER_TARGET_TYPE_DEFAULT,
			D2D1::PixelFormat(
			DXGI_FORMAT_B8G8R8A8_UNORM,
			D2D1_ALPHA_MODE_PREMULTIPLIED
			), 0.0F, 0.0F,
			D2D1_RENDER_TARGET_USAGE_GDI_COMPATIBLE
			);
		hr = m_pD2DFactory->CreateDCRenderTarget(
			&props, &m_pDCRenderTarget);
		if (!SUCCEEDED(hr)) return hr;
	}
return hr;
}

推荐答案

GHEORGHE_926，

Hi GHEORGHE_926,

感谢您在此发布。

>> I从流中创建了一个ID2D1Bitmap，但是当我尝试在屏幕上渲染ID2D1Bitmap时，我什么都没看到。变量"pPixels"表示变量"pPixels"。包含正确的数据，所以，直到这一切都是好的。你看到我的代码在
中有什么问题吗？

如果DrawBitmap方法失败，它不会返回错误代码。判断是否有绘图操作 失败，检查
返回的结果
ID2D1RenderTarget :: EndDraw 或
ID2D1RenderTarget :: Flush 方法。

The DrawBitmap method doesn't return an error code if it fails. To determine whether a drawing operation  failed, check the result returned by the ID2D1RenderTarget::EndDraw or ID2D1RenderTarget::Flush methods.

然后提供错误代码（如果有），以便我们找到根本原因。

Then provide the error code if there has, so that we could find the root cause.

最好的问候，

Sera Yu

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