TextBox只能输入数字的最简洁方法！

如下TextBox

< asp:textbox  onkeypress ="isnum()"  id ="TextBox1"  runat ="server" ></ asp:textbox >

1. 在页面中添加一段脚本：

< script  language ="javascript" >
     function  isnum()
    {
         if (event.keyCode < 45   ||  event.keyCode > 57 )
        {
            event.keyCode = 0 ;
        }
    }                             
</ script >

2. 在代码中添加：

try
{
    Convert.ToDouble(TextBox1.Text.Trim());
}
catch
{
    Response.Write( " <script>alert('请输入正确的数字格式！');</script> " );
    TextBox1.Text = "" ;
    Page.RegisterStartupScript( " focus " , " <script>document.forms[0]['TextBox1'].focus();</script> " );
}

就ok了，是不是很简洁啊? ^_^