可以用TImage作为画布,在窗体上放个TImage控件,设置Image为矩形。
绘图代码如下:
procedureTFmMain.btnDrawClick(Sender:TObject);
var
i,r:integer;
begin
//绘制矩形
imgCanvas.Canvas.Pen.Color:=clBlack;
imgCanvas.Canvas.MoveTo(0,0);
imgCanvas.Canvas.LineTo(imgCanvas.Width-1,0);
imgCanvas.Canvas.LineTo(imgCanvas.Width-1,imgCanvas.Height-1);
imgCanvas.Canvas.LineTo(0,imgCanvas.Height-1);
imgCanvas.Canvas.LineTo(0,0);
//绘制圆
r:=imgCanvas.Heightdiv2-2;
fori:=10downto1do
begin
//采用随机色画圆
imgCanvas.Canvas.Pen.Color:=Random($FFFFFF);
imgCanvas.Canvas.Ellipse(imgCanvas.Widthdiv2-r,
imgCanvas.Heightdiv2-r,
imgCanvas.Widthdiv2+r,
imgCanvas.Heightdiv2+r);
r:=r-10;
end;
end;
把绘图代码放在定时器里执行,还会有动画效果
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