c#中设置像数量，价格，金额等的textbox的限制条件，用户只能输入数字或小数

 1        #region 设置数量等textbox控件样式及限制条件（具体调用的方法就是重写或直接调用ShieldNumberTextBoxOtherKeys函数）
 2 
 3         /// <summary>
 4         /// 屏蔽数字textbox的其他字符串
 5         /// </summary>
 6         /// <param name="sender"></param>
 7         /// <param name="e"></param>
 8         public virtual void tBoxNumbers_KeyDown(object sender, KeyEventArgs e)
 9         {
10             e.SuppressKeyPress = true;
11 
12             switch (e.KeyCode)
13             {
14                 case Keys.D0:
15                 case Keys.D1:
16                 case Keys.D2:
17                 case Keys.D3:
18                 case Keys.D4:
19                 case Keys.D5:
20                 case Keys.D6:
21                 case Keys.D7:
22                 case Keys.D8:
23                 case Keys.D9:
24                 case Keys.NumPad0:
25                 case Keys.NumPad1:
26                 case Keys.NumPad2:
27                 case Keys.NumPad3:
28                 case Keys.NumPad4:
29                 case Keys.NumPad5:
30                 case Keys.NumPad6:
31                 case Keys.NumPad7:
32                 case Keys.NumPad8:
33                 case Keys.NumPad9:
34                 case Keys.Back:
35                 case Keys.OemPeriod:
36                 case Keys.Delete:
37                 case Keys.Decimal:
38                     e.SuppressKeyPress = false;
39                     break;
40                 default:
41                     break;
42             }
43         }
44 
45         public virtual void tBoxNumbers_KeyPress(object sender, KeyPressEventArgs e)
46         {
47             TextBox tBox = sender as TextBox;
48             char c = e.KeyChar;
49 
50             if (c.ToString().Equals("."))
51             {
52                 if (tBox.Text.Length <= 0)
53                     e.Handled = true;           //小数点不能在第一位     
54                 else
55                 {
56                     float f;
57                     float oldf;
58                     bool b1 = false, b2 = false;
59                     b1 = float.TryParse(tBox.Text, out oldf);
60                     b2 = float.TryParse(tBox.Text + e.KeyChar.ToString(), out f);
61                     if (b2 == false)
62                     {
63                         if (b1 == true)
64                             e.Handled = true;
65                         else
66                             e.Handled = false;
67                     }
68                 }
69             }
70         }
71 
72         /// <summary>
73         /// 屏蔽数字textbox的其他字符串
74         /// </summary>
75         /// <param name="tbox">要屏蔽的textbox</param>
76         public virtual void ShieldNumberTextBoxOtherKeys(TextBox tbox)
77         {
78             tbox.ImeMode = ImeMode.Disable;
79             tbox.KeyDown += tBoxNumbers_KeyDown;
80             tbox.KeyPress += tBoxNumbers_KeyPress;
81         }
82 
83         #endregion