GDI+ 学习记录(27) Bitmap

//用 Bitmap 显示图像
var
  g:TGPGraphics;
  bit:TGPBitmap;
begin
  g:=TGPGraphics.Create(Canvas.Handle);
  g.Clear(aclWhite);

  bit:=TGPBitmap.Create('d:\mm.jpg');

  g.DrawImage(bit,11,11); {没有指定宽高，默认大小可能跟分辨率有关}
  g.DrawImage(bit,250,11,bit.GetWidth,bit.GetHeight);{1:1}
  g.DrawImage(bit,11,210,0.5*bit.GetWidth,0.5*bit.GetHeight);{2:1}

  bit.Free;
  g.Free;
end;

//复制像素
var
  g:TGPGraphics;
  bit1,bit2:TGPBitmap;
  pixh,pixw,width,height:Integer;
  color:TGPColor;
begin
  g:=TGPGraphics.Create(Canvas.Handle);
  g.Clear(aclWhite);

  bit1:=TGPBitmap.Create('d:\mm.jpg');

  width:=bit1.GetWidth;
  height:=bit1.GetHeight;

  bit2:=TGPBitmap.Create(width,height);
  for pixh := 0 to height - 1 do       //纵向像素逐个复制
  begin
    for pixw := 0 to width - 1 do      //横向像素逐个复制
      begin
        bit1.GetPixel(pixw,pixh,color);
        bit2.SetPixel(pixw,pixh,color);
      end;
  end;
  g.DrawImage(bit1,0,0,width,height);
  g.DrawImage(bit2,width + 10,0,width,height);

  bit1.Free;
  bit2.Free;
  g.Free;

//横向翻转
var
  g:TGPGraphics;
  bit1,bit2:TGPBitmap;
  pixw,pixh,width,height:Integer;
  color:TGPColor;
begin
  g:=TGPGraphics.Create(Canvas.Handle);
  g.Clear(aclWhite);

  bit1:=TGPBitmap.Create('d:\mm.jpg');
  width:=bit1.GetWidth;
  height:=bit1.GetHeight;

  bit2:=TGPBitmap.Create(width,height);

  for pixh := 0 to height - 1 do
    begin
      for pixw := 0 to width - 1 do
        begin
          bit1.GetPixel(pixw,pixh,color);
          bit2.SetPixel((width - 1) - pixw,pixh,color); {(width - 1) - pixw}
        end;
    end;
  g.DrawImage(bit1,0,0,width,height);
  g.DrawImage(bit2,width + 10,0,width,height);

  bit1.Free;
  bit2.Free;
  g.Free;
end;

//纵向翻转
var
  g:TGPGraphics;
  bit1,bit2:TGPBitmap;
  pixw,pixh,width,height:Integer;
  color:TGPColor;
begin
  g:=TGPGraphics.Create(Canvas.Handle);
  g.Clear(aclWhite);

  bit1:=TGPBitmap.Create('d:\mm.jpg');
  width:=bit1.GetWidth;
  height:=bit1.GetHeight;

  bit2:=TGPBitmap.Create(width,height);

  for pixh := 0 to height - 1 do
    begin
      for pixw := 0 to width - 1 do
        begin
          bit1.GetPixel(pixw,pixh,color);
          bit2.SetPixel(pixw,(height - 1) - pixh,color); {(height - 1) - pixh}
        end;
    end;
  g.DrawImage(bit1,0,0,width,height);
  g.DrawImage(bit2,width + 10,0,width,height);

  bit1.Free;
  bit2.Free;
  g.Free;
end;

//透明度渐变
var
  g:TGPGraphics;
  bit1,bit2:TGPBitmap;
  pixw,pixh,width,height:Integer;
  color:TGPColor;
begin
  g:=TGPGraphics.Create(Canvas.Handle);
  g.Clear(aclWhite);

  bit1:=TGPBitmap.Create('d:\mm.jpg');
  width:=bit1.GetWidth;
  height:=bit1.GetHeight;

  bit2:=TGPBitmap.Create(width,height);
  for pixh := 0 to height - 1 do
    begin
      for pixw := 0 to width - 1 do
        begin
          bit1.GetPixel(pixw,pixh,color);
          color:=MakeColor(255*pixw div width,GetRed(color),GetGreen(color),GetBlue(color));
          bit2.SetPixel(pixw,pixh,color);
        end;
    end;
  g.DrawImage(bit1,0,0,width,height);
  g.DrawImage(bit2,width + 10,0,width,height);

  bit1.Free;
  bit2.Free;
  g.Free;
end;

//显示 ico 图标
var
  g:TGPGraphics;
  bit:TGPBitmap;
  ico:HICON;
begin
  g:=TGPGraphics.Create(Canvas.Handle);
  g.Clear(aclWhite);

  ico:= LoadIcon(0,IDI_QUESTION);
  bit:=TGPBitmap.Create(ico);

  g.DrawImage(bit,10,10);

  bit.Free;
  g.Free;
end;