只有底边的TextBox 

 1 using System.Windows.Forms;
 2 using System.Drawing;
 3 
 4 namespace WindowsFormsApplication1
 5 {
 6     public partial class LineTextBox : TextBox
 7     {
 8         public LineTextBox()
 9         {
10             this.Multiline = false;
11             this.Width = 100;
12             this.Height = 20;
13             this.BorderStyle = BorderStyle.None;
14         }
15         private Color _linecolor = Color.Black;
16         /// <summary>
17         /// 线条颜色
18         /// </summary>
19         public Color LineColor
20         {
21             get
22             {
23                 return this._linecolor;
24             }
25             set
26             {
27                 this._linecolor = value;
28                 this.Invalidate();
29             }
30         }
31         private const int WM_PAINT = 0xF;
32         protected override void WndProc(ref Message m)
33         {
34             base.WndProc(ref m);
35             if (m.Msg == WM_PAINT)
36             {
37                 DrawLine();
38             }
39         }
40         //只画底边
41         private void DrawLine()
42         {
43             Graphics g = this.CreateGraphics();
44             using (Pen p = new Pen(this._linecolor))
45             {
46                 g.DrawLine(p, 0, this.Height -1, this.Width, this.Height -1);
47             }
48         }
49     }
50 }
posted @ 2011-03-28 00:28  diaboo  阅读(171)  评论(0)    收藏  举报