StringHelper--字符串左右添加指定字符

StringHelper--字符串左右添加指定字符

using System;
using System.Collections.Generic;
using System.Configuration;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace HRMessageApp.Helper
{
    public class StringHelper
    {
        //定义一个用于保存静态变量的实例
        private static StringHelper instance = null;
        //定义一个保证线程同步的标识
        private static readonly object locker = new object();
        //构造函数为私有，使外界不能创建该类的实例
        private StringHelper() { }
        public static StringHelper Instance
        {
            get
            {
                if (instance == null)
                {
                    lock (locker)
                    {
                        if (instance == null) instance = new StringHelper();
                    }
                }
                return instance;
            }
        }

        public string StrAppendChar(string str, char pChar = '"')
        {
            StringBuilder buf = new StringBuilder();
            buf.Append(pChar);
            buf.Append(str);
            buf.Append(pChar);
            return buf.ToString();
        }


        public string StrPadRightAndLeft(string str, char pChar = '"')
        {
            string one = str.PadLeft(str.Length + 1, pChar); ;
            string two = one.PadRight(one.Length + 1, pChar);

            return two;
        }

        public string StrLeftRightAppendChar(string str, char pChar = '"')
        {
            //string one = str.Replace(str.Substring(0, 1), pChar + str.Substring(0, 1));
            string one = str.Replace(str, pChar + str);
            string two = one.Replace(one, one + pChar);

            return two;
        }

        public string StrLeftRightInsertChar(string str, char pChar='"')
        {
            string one = str.Insert(0, pChar.ToString()); //Insert() 在字串中指定索引位插入指定字符
            string two = one.Insert(one.Length, pChar.ToString());

            return two;
        }

        public string StrLeftRightPlusChar(string str, char pChar = '"')
        {
            return pChar + str + pChar;
        }

        public string StrLeftRightAddChar(string str, char pChar = '"')
        {
            //string result = $"{pChar}{str}{pChar}";
            return $"{pChar}{str}{pChar}"; 
        }


    }
}

补充方法：

      private static string MergeString(params string[] strs)
      {
          //string message = MergeString("\"", "abc", "\"");
          string result = string.Empty;
          foreach (string str in strs)
          {
              result = result + str;
          }
          return result;
      }