如何转换 FMX.Graphics.TBitmap to VCL.Graphics.TBitmap 或 Vcl.Imag

Question

How a FMX.Graphics.TBitmap 可以转换为 VCL.Graphics.TBitmap 或 Vcl.Imaging.PngImage.TPngImage？

我的项目中同时有FMX表格和VCL表格。

Answer 1

感谢David Heffernan和一些搜索，我将这些函数编写如下。

我首先想出了不支持 Alpha 的函数

function ConvertFmxBitmapToVclBitmap(b:FMX.Graphics.TBitmap):Vcl.Graphics.TBitmap;
var
  data:FMX.Graphics.TBitmapData;
  i,j:Integer;
  AlphaColor:TAlphaColor;
begin
  Result:=VCL.Graphics.TBitmap.Create;
  Result.SetSize(b.Width,b.Height);
  if(b.Map(TMapAccess.Readwrite,data))then
  try
    for i := 0 to data.Height-1 do begin
      for j := 0 to data.Width-1 do begin
        AlphaColor:=data.GetPixel(i,j);
        Result.Canvas.Pixels[i,j]:=
          RGB(
            TAlphaColorRec(AlphaColor).R,
            TAlphaColorRec(AlphaColor).G,
            TAlphaColorRec(AlphaColor).B);
      end;
    end;
  finally
    b.Unmap(data);
  end;
end;

我编写了第二个函数来转换 FMX。Graphics.TBitmap to Vcl.Imaging.PngImage.TPngImage 并支持 Alpha。

function ConvertFmxBitmapToPng(b:FMX.Graphics.TBitmap):Vcl.Imaging.PngImage.TPngImage;
var
  data:FMX.Graphics.TBitmapData;
  i,j:Integer;
  AlphaColor:TAlphaColor;
  AlphaLine:VCL.Imaging.PngImage.pByteArray;
begin
  result:=TPngImage.CreateBlank(COLOR_RGBALPHA, 8, b.Width, b.Height);;
  if(b.Map(TMapAccess.Readwrite,data))then
  try
    for i := 0 to data.Height-1 do begin
      AlphaLine:=Result.AlphaScanline[i];
      for j := 0 to data.Width-1 do begin
        AlphaColor:=data.GetPixel(j,i);
        AlphaLine^[j]:=TAlphaColorRec(AlphaColor).A;
        Result.Pixels[j,i]:=
          RGB(
            TAlphaColorRec(AlphaColor).R,
            TAlphaColorRec(AlphaColor).G,
            TAlphaColorRec(AlphaColor).B);
      end;
    end;
  finally
    b.Unmap(data);
  end;
end;

Answer 2

更正以处理矩形图像：

function 
    ConvertFmxBitmapToVclBitmap(b:FMX.Graphics.TBitmap):Vcl.Graphics.TBitmap;
var
  data:FMX.Graphics.TBitmapData;
  i,j:Integer;
  AlphaColor:TAlphaColor;
begin
  Result:=VCL.Graphics.TBitmap.Create;
  Result.SetSize(b.Width,b.Height);
  if(b.Map(TMapAccess.Readwrite,data))then
  try
    for i := 0 to data.Height-1 do begin
      for j := 0 to data.Width-1 do begin
        AlphaColor:=data.GetPixel(j,i);
        Result.Canvas.Pixels[j,i]:=
          RGB(
            TAlphaColorRec(AlphaColor).R,
            TAlphaColorRec(AlphaColor).G,
            TAlphaColorRec(AlphaColor).B);
      end;
    end;
  finally
    b.Unmap(data);
  end;
end;