如何将Direct2D画布绘制到TcxImage画布上？

问题描述

| 我有一个Direct2D演示，该演示创建GridPatternBitmapBrush，然后以Paint方法在TForm上绘制网格图案。如何使Direct2D GridPatternBitmapBrush出现在表单的TcxImage.Canvas（DeveloperExpress timage）内？

procedure TFormAdvGeometries.Create_FRadialGradientBrush;
var
//  aGradientStops: array of TD2D1GradientStop;
//  aGradBrushProps: TD2D1RadialGradientBrushProperties;
//  aGradStopsCollection: ID2D1GradientStopCollection;

  gradColors: array of TColor;
begin
  SetLength(gradColors,3);
  gradColors[0] := TColor($00D7FF); // Gold (D2D1Helper.h)
  gradColors[1] := TColor($00A5FF); // Orange (D2D1Helper.h)
  gradColors[2] := TColor($0045FF); // OrangeRed (D2D1Helper.h)


  // this is a place-holder.
  // Code below assumes equal spread for positions in gradient stops
  FRadialGradientBrush := d2dCanvas.CreateBrush(
    gradColors,D2D1PointF(330,330),D2D1PointF(140,140),140,140
    );
end;

procedure TFormAdvGeometries.Create_FGridPatternBitmapBrush;
var
  gridBrush: ID2D1SolidColorBrush;
  bmpBrushProps: D2D1_BITMAP_Brush_PROPERTIES;
  bitmaprendertarget: ID2D1Bitmaprendertarget;
  bmpSize: D2D_SIZE_F;
  gridBitmap: ID2D1Bitmap;
begin
  bmpSize.width := 10;
  bmpSize.height := 10;
  d2dCanvas.rendertarget.CreateCompatiblerendertarget(
    @bmpSize,nil,bitmaprendertarget);
  bitmaprendertarget.CreateSolidColorBrush(
    D2D1ColorF(0.93,0.94,0.96,1),gridBrush);
  bitmaprendertarget.BeginDraw;
  bitmaprendertarget.FillRectangle(Rect(0,10,gridBrush);
  bitmaprendertarget.FillRectangle(Rect(0,1,10),gridBrush);
  bitmaprendertarget.EndDraw;
  bitmaprendertarget.GetBitmap(gridBitmap);
  bmpBrushProps.extendModeX := D2D1_EXTEND_MODE_WRAP;
  bmpBrushProps.extendModeY := D2D1_EXTEND_MODE_WRAP;
  bmpBrushProps.interpolationMode := 0; // Could be 1
  d2dCanvas.rendertarget.CreateBitmapBrush(
    gridBitmap,@bmpBrushProps,FGridPatternBitmapBrush);
end;

procedure TFormAdvGeometries.CreateDeviceResources;
begin
  Create_FRadialGradientBrush;
  Create_FGridPatternBitmapBrush;
end;

procedure TFormAdvGeometries.Paint;
var defMatrix: TD2DMatrix3x2F;
begin
  inherited;

  CreateDeviceResources;

  d2dCanvas.BeginDraw;
  try
    d2dCanvas.rendertarget.GetTransform (defMatrix);

    // fill with white color the whole window
    d2dCanvas.rendertarget.Clear(D2D1ColorF(clWhite));

    // fill canvas with little blue rectangles
    d2dCanvas.Brush.Handle := FGridPatternBitmapBrush;
    d2dCanvas.Rectangle(0,ClientWidth + 50,ClientHeight + 50);

    // reset standard transformation
    d2dCanvas.rendertarget.SetTransform (defMatrix);
  finally
    d2dCanvas.EndDraw;
  end;
end;

    

解决方法

您需要更改d2dCanvas的构造函数。 目前是

  d2dCanvas := TDirect2DCanvas.Create(Handle);

它传递表单句柄以创建画布。 我没有Delphi 2010（似乎随附了演示所需的单元），但我认为

  d2dCanvas := TDirect2DCanvas.Create(MyTcxImage.Canvas.Canvas,Rect(0,MyTcxImage.Width,MyTcxImage.Height));

应该做到的 您需要将Canvas.Canvas传递给此构造函数，因为cx组件（至少是我的版本）使用了包含TCanvas的TcxCanvas。 您可能可以将TcxImage控件的窗口句柄传递给Direct2DCanvas构造函数。