C#获取字符串后几位数的方法

#region 获取后几位数 public string GetLastStr(string str,int num)/// <summary>/// 获取后几位数/// </summary>/// <param name="str">要截取的字符串</param>/// <param name="num">返回的具体位数</param>/// <returns>返回结果的字符串</returns>public string GetLastStr(string str, int num){  int count = 0;  if (str.Length > num)  { count = str.Length - num; str = str.Substring(count, num);  }  return str;}#endregion