//验证用户输入的字符串中时候只含有数字或字母,汉字
   bool IsValidString(string strIn)
   {
    return Regex.IsMatch(strIn,@"^[A-Za-z0-9\u4e00-\u9fa5]+$");
   }
//验证电子邮件
   bool IsValidEmail(string strIn) 
   { 
    return 

Regex.IsMatch(strIn,@"^([\w-\.]+)@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.)|(([\w-]+\.)+))([a-zA-Z]{2,4}|[0-9]{1,3})(\]?)$"); 
   } 
//验证用户输入的字符串中时候只含有数字或字母
   bool IsValidString(string strIn)
   {
    return Regex.IsMatch(strIn,@"^[A-Za-z0-9]+$");
   }
/// <summary>
   /// 判断密码
   /// </summary>
   /// <param name="PassWord"></param>
   /// <returns></returns>
   public static bool IsValidPassWord(string PassWord)
   {
    return Regex.IsMatch(PassWord, @"^(\w){6,20}$"); 
   }

/// <summary>
   /// 判断电话/传真
   /// </summary>
   /// <param name="Tel"></param>
   /// <returns></returns>
   public static bool IsValidTel(string Tel)
   {
    return Regex.IsMatch(Tel, @"^[+]{0,1}(\d){1,3}[ ]?([-]?((\d)|[ ]){1,12})+$"); 
   }

/// <summary>
   /// 判断手机
   /// </summary>
   /// <param name="Mobil"></param>
   /// <returns></returns>
   public static bool IsValidMobil(string Mobil)
   {
    return Regex.IsMatch(Mobil, @"^(\d)+[-]?(\d){6,12}$"); 
   }

/// <summary>
   /// 邮政编码
   /// </summary>
   /// <param name="Zip"></param>
   /// <returns></returns>
   public static bool IsValidZip(string Zip)
   {
    return Regex.IsMatch(Zip, @"^[a-z0-9 ]{3,12}$"); 
   }

/// <summary>
   /// 判断日期
   /// </summary>
   /// <param name="Date"></param>
   /// <returns></returns>
   public static bool IsValidDate(string Date)
   {
    bool bValid=Regex.IsMatch(Date, @"^[12]{1}(\d){3}[-][01]?(\d){1}[-][0123]?(\d){1}$"); 
    return (bValid && Date.CompareTo("1753-01-01")>=0);

   }

//判断整型
   /*public static bool IsValidInt(string Int)
   {
    return Regex.IsMatch(Int, @"^[1-9]{1}[0-9]{0,6}$"); 
   }*/

   /// <summary>
   /// 判断只能输字母
   /// </summary>
   /// <param name="EnName"></param>
   /// <returns></returns>
   public static bool IsValidEnName(string EnName)
   {
    return Regex.IsMatch(EnName, @"[a-zA-Z]"); 
   }
C#判断字符串中是否有汉字
using System.Text.RegularExpressions;//先导入这个使用正则表达式


private void isHanzi(string str)
        { 
            Regex reg = new Regex(@"[u4e00-u9fa5]");//正则表达式
            if (reg.IsMatch(str))
            {
                MessageBox.Show("有汉字");
            }
            else
            {
                MessageBox.Show("没有汉字");
            }
        }
C#验证是否是合法邮箱
先 using System.Text.RegularExpressions;
然后按钮中加入
private void button1_Click(object sender, EventArgs e)
{
string reg = @"\w+([-+.]\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*";
Regex r = new Regex(reg);
if (r.IsMatch(textBox1.Text))
{
MessageBox.Show("格式正确");
}
else
{
MessageBox.Show("不是有效的email地址");
}
}