C# String的一些简单操作记录

        /// <summary>
        /// 替换字符串，仅第一个匹配项
        /// </summary>
        /// <param name="value">原始内容</param>
        /// <param name="oldValue">要替换的字符串</param>
        /// <param name="newValue">替换后的字符串</param>
        /// <returns></returns>
        private static string GetReplaceByFirst(string value, string oldValue, string newValue, StringComparison comparisonType = StringComparison.CurrentCulture)
        {
            int index = value.IndexOf(oldValue, comparisonType);
            if (index > -1)
            {
                value = value.Remove(index, oldValue.Length).Insert(index, newValue);
            }
            return value;
        }

        /// <summary>
        /// 替换字符串，除第一个匹配项
        /// </summary>
        /// <param name="value">原始内容</param>
        /// <param name="oldValue">要替换的字符串</param>
        /// <param name="newValue">替换后的字符串</param>
        /// <returns></returns>
        private static string GetReplaceByNotFirst(string value, string oldValue, string newValue, StringComparison comparisonType = StringComparison.CurrentCulture)
        {
            int index = value.IndexOf(oldValue, comparisonType);
            if (index > -1)
            {
                value = value.Substring(0, index + 1) + (value.Substring(index + 1).Replace(oldValue, newValue));
            }
            return value;
        }

保留小数点后几位

 .ToString("0.0");