using System;

 using System.Web;

 using System.Text;

 namespace quanbanjiao

 {

     public class Class1

     {

         /**/

         /// <summary>

         /// 判断字符是否英文半角字符或标点

         /// </summary>

         /// <remarks>

         /// 32    空格

         /// 33-47    标点

         /// 48-57    0~9

         /// 58-64    标点

         /// 65-90    A~Z

         /// 91-96    标点

         /// 97-122    a~z

         /// 123-126  标点

         /// </remarks>

         public static bool IsBjChar(char c)

         {

             int i = (int)c;

             return i >=  && i <= ;

         }

         /**/

         /// <summary>

         /// 判断字符是否全角字符或标点

         /// </summary>

         /// <remarks>

         /// <para>全角字符 - 65248 = 半角字符</para>

         /// <para>全角空格例外</para>

         /// </remarks>

         public static bool IsQjChar(char c)

         {

             if (c == '\u3000') return true;

             int i = (int)c - ;

             if (i < ) return false;

             return IsBjChar((char)i);

         }

         /* http://www.cnblogs.com/roucheng/ */

         /// <summary>

         /// 将字符串中的全角字符转换为半角

         /// </summary>

         public static string ToBj(string type,string s)

         {

             if (s == null || s.Trim() == string.Empty) return s;

             StringBuilder sb = new StringBuilder(s.Length);

             for (int i = ; i < s.Length; i++)

             {

                 if (s[i] == '\u3000')

                     sb.Append('\u0020');

                 else if (IsQjChar(s[i]))

                     sb.Append((char)((int)s[i] - ));

                 else

                     sb.Append(s[i]);

             }

             //如果是int类型的，则只能输入int类型，否则自动设为0

             if (type.ToLower() == "int")

             {

                 try

                 {

                     Convert.ToInt32(sb.ToString());

                 }

                 catch

                 {

                     return "";

                 }

             }

             //如果是float或double类型的，则只能输入这两种类型，否则自动设为0

             if (type.ToLower() == "float" || type.ToLower() == "double")

             {

                 try

                 {

                     Convert.ToDouble(sb.ToString());

                 }

                 catch

                 {

                     return "";

                 }

             }

             return sb.ToString();

         }

     }

 }

using System;

using System.Web;

using quanbanjiao;//项目名称为quanbanjiao

namespace quanbanjiao

{

    public partial class WebForm1 : System.Web.UI.Page

    {

// keleyi.com

        protected void Page_Load(object sender, EventArgs e)

        {

        }

        protected void Button1_Click(object sender, EventArgs e)

        {

            TextBox1.Text = Class1.ToBj("string", TextBox1.Text.Trim());

        }

    }

}