在.Net下進行WinForm開發,GroupBox是經常要用到的一個控件。但是GroupBox自身的邊框是灰白色的,其樣式很難令開發者滿意。在不借用第三方控件的情況下,通過其的Paint事件對GroupBox進行重畫,也可以很方便的修改其邊框顏色/樣式。
簡要說一下實現思路。首先用Clear方法清除GroupBox的顯示,接着再用合適的樣式把GroupBox畫出來。把GroupBox拆分為4個圓角,一行標題文字和數段直線等元素,把這些元素擺放在合適的位置,拼湊出GroupBox的外框。定義4個Rectangle(用於后面的畫圓角),確定它們的大小和位置;然后在確切的位置上畫4個弧段,按圓角在GroupBox上的位置確定其角度;接着在對應的位置畫出GroupBox標題和幾條直線,就大功告成了。只需簡單修改代碼中的設置顏色語句,便可以完成GroupBox邊框顏色的更換了。
using
System;
using
System.Collections.Generic;
using
System.ComponentModel;
using
System.Data;
using
System.Drawing;
using
System.Drawing.Drawing2D;
using
System.Text;
using
System.Windows.Forms;
namespace
WindowsApplication2
{
public
partial
class
Form1 : Form
{
public
Form1()
{
InitializeComponent();
}
private
void
groupBox1_Paint(
object
sender, PaintEventArgs e)
{
e.Graphics.Clear(groupBox1.BackColor);
Rectangle Rtg_LT =
new
Rectangle();
Rectangle Rtg_RT =
new
Rectangle();
Rectangle Rtg_LB =
new
Rectangle();
Rectangle Rtg_RB =
new
Rectangle();
Rtg_LT.X = 0; Rtg_LT.Y = 7; Rtg_LT.Width = 10; Rtg_LT.Height = 10;
Rtg_RT.X = e.ClipRectangle.Width - 11; Rtg_RT.Y = 7; Rtg_RT.Width = 10; Rtg_RT.Height = 10;
Rtg_LB.X = 0; Rtg_LB.Y = e.ClipRectangle.Height - 11; Rtg_LB.Width = 10; Rtg_LB.Height = 10;
Rtg_RB.X = e.ClipRectangle.Width - 11; Rtg_RB.Y = e.ClipRectangle.Height - 11; Rtg_RB.Width = 10; Rtg_RB.Height = 10;
Color color = Color.FromArgb(51, 94, 168);
Pen Pen_AL =
new
Pen(color, 1);
Pen_AL.Color = color;
Brush brush =
new
HatchBrush(HatchStyle.Divot, color);
e.Graphics.DrawString(groupBox1.Text, groupBox1.Font, brush, 6, 0);
e.Graphics.DrawArc(Pen_AL, Rtg_LT, 180, 90);
e.Graphics.DrawArc(Pen_AL, Rtg_RT, 270, 90);
e.Graphics.DrawArc(Pen_AL, Rtg_LB, 90, 90);
e.Graphics.DrawArc(Pen_AL, Rtg_RB, 0, 90);
e.Graphics.DrawLine(Pen_AL, 5, 7, 6, 7);
e.Graphics.DrawLine(Pen_AL, e.Graphics.MeasureString(groupBox1.Text, groupBox1.Font).Width + 3, 7, e.ClipRectangle.Width - 7, 7);
e.Graphics.DrawLine(Pen_AL, 0, 13, 0, e.ClipRectangle.Height - 7);
e.Graphics.DrawLine(Pen_AL, 6, e.ClipRectangle.Height - 1, e.ClipRectangle.Width - 7, e.ClipRectangle.Height - 1);
e.Graphics.DrawLine(Pen_AL, e.ClipRectangle.Width - 1, e.ClipRectangle.Height - 7, e.ClipRectangle.Width - 1, 13);
}
}
}