lisa3137回复于24日09点21分　

因为你的坐标已经起出了PaintBox的范围了,画布最大也就在Width-1那里加上Left就超出了,改成如下即可
Delphi(Pascal) code with paintbox1 do begin canvas.MoveTo(left,top); canvas.LineTo(left,top+height); canvas.MoveTo(left,top); canvas.LineTo(left+width,top); end;

 

andyzpn回复于24日09点29分　

设置笔宽能看到一点
Canvas.pen.width:=......

 

zh8851回复于24日09点37分　

Delphi(Pascal) code begin with Self.PaintBox1 do begin Canvas.Pen.Color := clRed; Canvas.Pen.Width := 5; canvas.MoveTo(width, 0); canvas.LineTo(width, height); canvas.MoveTo(0, height); canvas.LineTo(width, height); end; end;
你的已经越界了

 

水果篮子回复于24日09点44分　

left+width已经超出了paintbox1 的画布范围,你得坐标取值有问题