textbox只能输入小数

 1 /// <summary>
 2 /// txtbox只能输入小数
 3 /// </summary>
 4 /// <param name="sender"></param>
 5 /// <param name="e"></param>
 6         private void txtzhongxiang_KeyPress(object sender, KeyPressEventArgs e)
 7         {
 8             if (!(Char.IsNumber(e.KeyChar)) && e.KeyChar != (char)13 && e.KeyChar != (char)8)
 9             {
10                 int i = ((TextBox)sender).Text.IndexOf(‘.‘);
11                 if (e.KeyChar == ‘.‘ && ((TextBox)sender).Text.IndexOf(‘.‘) == -1)
12                 {
13 
14                     e.Handled = false;
15                 }
16                 else
17                 {
18                     e.Handled = true;
19                 }
20             }
21             else
22             {
23                 if (e.KeyChar == (char)13)
24                 {
25                     button3_Click(sender, e);
26                 }
27                 else
28                     e.Handled = false;
29             }
30         }