C# 会自动替换 变量 把形如 "{{varName}}" 替换成对应的数值

C# 会自动替换 变量   把形如 "{{varName}}" 替换成对应的数值

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading.Tasks;

namespace Common
{
    public class DynamicVariableHelper
    {
        /// <summary>
        /// 会自动替换 变量   把形如 "{{varName}}" 替换成对应的数值
        /// </summary>
        public static void ReplaceFileVar(string srcFile, string targetFile)
        {
            /*
            * 设置webconfig连接字符串
            */
            string webconfigpath = Path.Combine("./", srcFile);
            //修改第一个数据库连接
            string webcofnigstring2 = File.ReadAllText(webconfigpath);

            webcofnigstring2 = ReplaceStringVar(webcofnigstring2);

            //循环替换所有的 {{DBSERVER}} 这种变量 效率比较低,改成上面的replace
            //foreach (Match item in mat)
            //{
            //    Console.WriteLine(item.Groups[1]);
            //    var name = item.Groups[1].Value;
            //    if (! string.IsNullOrEmpty( InstallContext.Get(name)))
            //    {
            //         webcofnigstring2.Replace(@"{{"+ name + "}}", InstallContext.Get(name));
            //    }
            //}

            File.WriteAllText(targetFile, webcofnigstring2);
        }


        /// <summary>
        /// 会自动替换 变量   把形如 "{{varName}}" 替换成对应的数值
        /// </summary>
        public static string ReplaceStringVar(string str)
        {
            Regex reg = new Regex(@"\{\{(.*?)\}\}");
            //var mat = reg.Matches(webcofnigstring2);

            str = reg.Replace(str,
                new MatchEvaluator(m =>
                     InstallContext.Get(m.Groups[1].Value) == string.Empty ? m.Value : InstallContext.Get(m.Groups[1].Value)
                ));
            return str;
        }
    }

    public static class InstallContext
    {
        private static Dictionary<string, string> kvs = new Dictionary<string, string>();

        public static string Get(string index)
        {
            if (kvs.ContainsKey(index))
            {
                return kvs[index];
            }
            else
            {
                return string.Empty;
            }
        }
        public static void Set(string index, string value)
        {
            kvs[index] = value;
        }



        //private static InstallContext instance = new InstallContext();

        //private InstallContext()
        //{

        //}

        //public static InstallContext GetInstance()
        //{ 
        //    return instance;
        //}

    }
}