使用canvas时遇到的问题(20分)

Y

ykjt

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• 2004-01-01

• #1

使用canvas时遇到的
procedure TForm1.Button1Click(Sender: TObject);
var
p:trect;
begin
p.Left:=image1.Left;
p.Top:=image1.Top;
p.Right:=image1.Width;
p.Bottom:=image1.Height;
edit1.Text:=inttostr(p.Right);
canvas.Brush.Style:= bsfdiagonal;
canvas.Brush.Color:=$0032bb22;
canvas.FillRect(p);
end;
本想覆盖整个image1,结果却覆盖了四分之一,是何原因？

 

C

cqbaobao

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• 2004-01-01

• #2

最后一句差了一个对象，应为：

image1.canvas.FillRect(p);

 

H

hongxing_dl

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• 2004-01-01

• #3

procedure TForm1.Button1Click(Sender: TObject);
var
p:trect;
begin
p.Left:=image1.Left;
p.Top:=image1.Top;
p.Right:=image1.Left+image1.Width;
p.Bottom:=image1.Top+image1.Height;
edit1.Text:=inttostr(p.Right);
canvas.Brush.Style:= bsfdiagonal;
canvas.Brush.Color:=$0032bb22;
canvas.FillRect(p);
end;

 

Y

ykjt

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• 2004-01-01

• #4

不行，出错

 

W

weichao9999

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• 2004-01-01

• #5

p的位置是相对于窗体的
p.Left :=0;
p.Top :=0;
p.Right:=image1.Width;
p.Bottom:=image1.Height;
edit1.Text:=inttostr(p.Right);
canvas.Brush.Style:= bsfdiagonal;
canvas.Brush.Color:=$0032bb22;
canvas.FillRect(p);

运行一下就知道了
自己该程序吧，不难。

 

W

weichao9999

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• 2004-01-01

• #6

p.Left:=image1.Left;
p.Top:=image1.Top;
//p.Left :=0;
//p.Top :=0;
p.Right:=image1.Width+image1.Left;;
p.Bottom:=image1.Height+image1.Top;;
edit1.Text:=inttostr(p.Right);
canvas.Brush.Style:= bsfdiagonal;
canvas.Brush.Color:=$0032bb22;
canvas.FillRect(p);
这样就行了

 

Y

ykjt

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GUEST, unregistred user!

• 2004-01-01

• #7

hongxing_dl的是对的

 

Y

ykjt

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• 2004-01-01

• #8

weichao9999也对