string strToProcess = "fkdfdsfdflkdkfk@dfsdfjk72388389@kdkfkdfkkl@jkdjkfjd@jjjk@";
var result = strToProcess.Replace("@", "@ \r\n");
Console.WriteLine(result);

输出

正如其他人所说，new line char将在windows中的文本文件中为您提供新行。 试试下面的方法:

using System;
using System.IO;

static class Program
{
    static void Main()
    {
        WriteToFile
        (
        @"C:\test.txt",
        "fkdfdsfdflkdkfk@dfsdfjk72388389@kdkfkdfkkl@jkdjkfjd@jjjk@",
        "@"
        );

        /*
        output in test.txt in windows =
        fkdfdsfdflkdkfk@
        dfsdfjk72388389@
        kdkfkdfkkl@
        jkdjkfjd@
        jjjk@ 
        */
    }

    public static void WriteToFile(string filename, string text, string newLineDelim)
    {
        bool equal = Environment.NewLine == "\r\n";

        //Environment.NewLine == \r\n = True
        Console.WriteLine("Environment.NewLine == \\r\\n = {0}", equal);

        //replace newLineDelim with newLineDelim + a new line
        //trim to get rid of any new lines chars at the end of the file
        string filetext = text.Replace(newLineDelim, newLineDelim + Environment.NewLine).Trim();

        using (StreamWriter sw = new StreamWriter(File.OpenWrite(filename)))
        {
            sw.Write(filetext);
        }
    }
}

更改您的字符串如下所述。

string strToProcess = "fkdfdsfdflkdkfk"+ System.Environment.NewLine +" dfsdfjk72388389"+ System.Environment.NewLine +"kdkfkdfkkl"+ System.Environment.NewLine +"jkdjkfjd"+ System.Environment.NewLine +"jjjk"+ System.Environment.NewLine;

使用环境。你可以在任何字符串中使用换行符。一个例子:

string text = "fkdfdsfdflkdkfk@dfsdfjk72388389@kdkfkdfkkl@jkdjkfjd@jjjk@";

text = text.Replace("@", "@" + System.Environment.NewLine);

前面的答案很接近，但为了满足@符号保持接近的实际要求，您希望它是str.Replace("@"， "@" + System.Environment.NewLine)。这将保留@符号，并为当前平台添加适当的换行符。

string str = "fkdfdsfdflkdkfk@dfsdfjk72388389@kdkfkdfkkl@jkdjkfjd@jjjk@";
str = str.Replace("@", Environment.NewLine);
richTextBox1.Text = str;