c#随机生成字符串

using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Text;

/// <summary>
/// RandStr 的摘要说明
/// </summary>
public class RandStr
{
    private Random m_rnd = new Random();

    #region 构造函数
    
    public RandStr()
	{
		//
		// TODO: 在此处添加构造函数逻辑
		//
    }

    #endregion

    #region 获取随机字符

    /// <summary>
    /// 获取随机字符
    /// </summary>
    /// <returns></returns>
    public char getRandomChar()
    {
        int ret = m_rnd.Next(122);
        while (ret < 48 || (ret > 57 && ret < 65) || (ret > 90 && ret < 97))
        {
            ret = m_rnd.Next(122);
        }
        return (char)ret;
    }

    #endregion

    #region 获取随机字符串

    /// <summary>
    /// 获取随机字符串
    /// </summary>
    /// <param name="length">字符长度</param>
    /// <returns></returns>
    public string getRandomString(int length)
    {
        StringBuilder sb = new StringBuilder(length);
        for (int i = 0; i < length; i++)
        {
            sb.Append(getRandomChar());
        }
        return sb.ToString();
    }

    #endregion

}