Question

C# 替换一个文本中的指定字符

123.txt里有很多行文本，其中有一行文本为123456789，现在我要把这行文本替换为9527，请问C#怎么写代码，要简洁的

Answer 1

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;

namespace ConsoleApplication12
{
class Program
{
static void Main(string[] args)
{
string path = @"config.txt";
string con = "";
FileStream fs = new FileStream(path, FileMode.Open, FileAccess.Read);
StreamReader sr = new StreamReader(fs);
con = sr.ReadToEnd();
con=con.Replace("123456789", "9527");
sr.Close();
fs.Close();
FileStream fs2 = new FileStream(path, FileMode.Open, FileAccess.Write);
StreamWriter sw = new StreamWriter(fs2);
sw.WriteLine(con);
sw.Close();
fs2.Close();

}

}

}

Answer 2

string path = @"123.txt";//文件路径
string con = "";
FileStream fs = new FileStream(path, FileMode.Open, FileAccess.Read);
StreamReader sr = new StreamReader(fs);
con = sr.ReadToEnd();//读取文件内的内容
con=con.Replace("123456789", "9527");//读取后替换
sr.Close();
fs.Close();
FileStream fs2 = new FileStream(path, FileMode.Open, FileAccess.Write);
StreamWriter sw = new StreamWriter(fs2);
sw.WriteLine(con);//新内容写入文件
sw.Close();
fs2.Close();

Answer 3

string 类中有一个 substring 和 indexof 这两个方法 你一看就好了 直接替换掉了就

Answer 4

string.Format