ID2D1DeviceContext EndDraw繪製矩形後的D2DERR_WRONG_STATE

Question

我嘗試使用Direct2D繪製矩形。初始化的Direct2D設備和Direct2D的設備上下文和設置渲染目標，在下面的描述MSDN article後，我試圖繪製一個矩形，如下所示：

HRESULT result; 
    result = g_d2dContext->CreateSolidColorBrush(
    D2D1::ColorF(D2D1::ColorF::Blue), 
    &g_SolidBrush 
    ); 

    D2D1_RECT_F rect = D2D1::RectF(
    g_targetRect.left + 10.0f, 
    g_targetRect.top + 10.0f, 
    g_targetRect.right - 10.0f, 
    g_targetRect.bottom - 10.0f); 

    g_d2dContext->BeginDraw(); 
    { 
    g_d2dContext->DrawRectangle(rect, g_SolidBrush, 5.0f); 
    } 
    result = g_d2dContext->EndDraw(); 

    if (FAILED(result)) 
    { 
    OutputDebugStringW(L"The object was not in the correct state to process the method."); 
    } 

的EndDraw（）方法返回下列HRESULT：0x88990001 (D2DERR_WRONG_STATE) - The object was not in the correct state to process the method。

矩形不會被繪製。我只得到一個黑色的圖像。

編輯：

我假設的問題是，得到一個NULL指針位圖/調用CreateBitmapFromDxgiSurface後渲染目標。

g_d2dContext->CreateBitmapFromDxgiSurface(
    dxgiBackBuffer.Get(), 
    &bitmapProperties, 
    &g_targetBitmap); 

    g_d2dContext->SetTarget(g_targetBitmap.Get()); 

但是爲什麼targetBitmap是NULL？

任何想法？

在此先感謝。

Answer 1

我剛解決了這個問題。我使用錯誤的值初始化了bitmapProperties。

現在，它的工作原理：

D2D1_BITMAP_PROPERTIES1 bitmapProperties = 
    D2D1::BitmapProperties1(
    D2D1_BITMAP_OPTIONS_TARGET | D2D1_BITMAP_OPTIONS_CANNOT_DRAW, 
    D2D1::PixelFormat(DXGI_FORMAT_B8G8R8A8_UNORM, D2D1_ALPHA_MODE_IGNORE), 
    96.0f, // dpi 
    96.0f // dpi 
    ); 

    // Direct2D needs the dxgi version of the backbuffer surface pointer. 
    ComPtr<IDXGISurface> dxgiBackBuffer; 
    hr = g_swapChain->GetBuffer(0, IID_PPV_ARGS(&dxgiBackBuffer)); 

    // Get a D2D surface from the DXGI back buffer to use as the D2D render target. 
    hr = g_d2dContext->CreateBitmapFromDxgiSurface(
    dxgiBackBuffer.Get(), 
    bitmapProperties, 
    g_targetBitmap.GetAddressOf()); 

    // Now we can set the Direct2D render target. 
    g_d2dContext->SetTarget(g_targetBitmap.Get());