GDI+ 学习记录(1): 画笔 Pen

//画笔
var
  g: TGPGraphics;
  p: TGPPen;
begin
  g := TGPGraphics.Create(Canvas.Handle);

  p := TGPPen.Create(aclRed, 2);
  {参数1颜色; 参数2是笔宽, 笔宽是可选, 默认 1}

  g.DrawEllipse(p, 11, 11, 222, 111);

  p.Free;
  g.Free;
end;


//设置笔宽与颜色
var
  g: TGPGraphics;
  p: TGPPen;
begin
  g := TGPGraphics.Create(Canvas.Handle);

  p := TGPPen.Create(aclBlack);
  {建立时应该不给参数是可以的, 但在测试中不行, 至少要给一个颜色}

  p.SetColor(aclBlue); {设置颜色}
  p.SetWidth(10);      {设置笔宽}

  g.DrawEllipse(p, 11, 11, 222, 111);

  p.Free;
  g.Free;
end;


//获取笔宽与颜色
var
  g: TGPGraphics;
  p: TGPPen;
  c: TGPColor;
begin
  g := TGPGraphics.Create(Canvas.Handle);

  p := TGPPen.Create(MakeColor(128,0,0,255), 10);

  g.DrawEllipse(p, 11, 11, 222, 111);

  p.GetColor(c);                       {获取颜色给 c}
  ShowMessage(IntToHex(c, 8));         {转换为十六进制: 800000FF}
  ShowMessage(FloatToStr(p.GetWidth)); {10}

  p.Free;
  g.Free;
end;