StringBuilderExtensions

        /// <summary>
        /// 去除<seealso cref="StringBuilder"/>开头的空格
        /// </summary>
        /// <param name="sb">StringBuilder</param>
        /// <returns>返回修改后的StringBuilder，主要用于链式操作</returns>
        public static StringBuilder TrimStart(this StringBuilder sb)
        
        /// <summary>
        /// 去除<seealso cref="StringBuilder"/>开头的指定<seealso cref="char"/>
        /// </summary>
        /// <param name="sb"></param>
        /// <param name="c">要去掉的<seealso cref="char"/></param>
        /// <returns></returns>
        public static StringBuilder TrimStart(this StringBuilder sb, char c)
        
        /// <summary>
        /// 去除<seealso cref="StringBuilder"/>开头的指定字符数组
        /// </summary>
        /// <param name="sb"></param>
        /// <param name="cs">要去掉的字符数组</param>
        /// <returns></returns>
        public static StringBuilder TrimStart(this StringBuilder sb, char[] cs)
        
        /// <summary>
        /// 去除<see cref="StringBuilder"/>开头的指定的<seealso cref="string"/>
        /// </summary>
        /// <param name="sb"></param>
        /// <param name="str">要去掉的<seealso cref="string"/></param>
        /// <returns></returns>
        public static StringBuilder TrimStart(this StringBuilder sb, string str)
        
        /// <summary>
        /// 去除StringBuilder结尾的空格
        /// </summary>
        /// <param name="sb">StringBuilder</param>
        /// <returns>返回修改后的StringBuilder，主要用于链式操作</returns>
        public static StringBuilder TrimEnd(this StringBuilder sb)
        
        /// <summary>
        /// 去除<see cref="StringBuilder"/>结尾指定字符
        /// </summary>
        /// <param name="sb"></param>
        /// <param name="c">要去掉的字符</param>
        /// <returns></returns>
        public static StringBuilder TrimEnd(this StringBuilder sb, char c)
        
        /// <summary>
        /// 去除<see cref="StringBuilder"/>结尾指定字符数组
        /// </summary>
        /// <param name="sb"></param>
        /// <param name="chars">要去除的字符数组</param>
        /// <returns></returns>
        public static StringBuilder TrimEnd(this StringBuilder sb, char[] chars)
        
        /// <summary>
        /// 去除<see cref="StringBuilder"/>结尾指定字符串
        /// </summary>
        /// <param name="sb"></param>
        /// <param name="str">要去除的字符串</param>
        /// <returns></returns>
        public static StringBuilder TrimEnd(this StringBuilder sb, string str)
        
        /// <summary>
        /// 去除StringBuilder两端的空格
        /// </summary>
        /// <param name="sb">StringBuilder</param>
        /// <returns>返回修改后的StringBuilder，主要用于链式操作</returns>
        public static StringBuilder Trim(this StringBuilder sb)
        
        /// <summary>
        /// 返回<see cref="StringBuilder"/>从起始位置指定长度的字符串
        /// </summary>
        /// <param name="sb"></param>
        /// <param name="start">起始位置</param>
        /// <param name="length">长度</param>
        /// <returns>字符串</returns>
        /// <exception cref="OverflowException">超出字符串索引长度异常</exception>
        public static string SubString(this StringBuilder sb, int start, int length)