var answer = Regex.Replace(value, "(\n|\r)+", replacementString);

如果你只想替换换行符:

var input = @"sdfhlu \r\n sdkuidfs\r\ndfgdgfd";
var match = @"[\\ ]+";
var replaceWith = " ";
Console.WriteLine("input: " + input);
var x = Regex.Replace(input.Replace(@"\n", replaceWith).Replace(@"\r", replaceWith), match, replaceWith);
Console.WriteLine("output: " + x);

如果你想替换换行符，制表符和空格:

var input = @"sdfhlusdkuidfs\r\ndfgdgfd";
var match = @"[\\s]+";
var replaceWith = "";
Console.WriteLine("input: " + input);
var x = Regex.Replace(input, match, replaceWith);
Console.WriteLine("output: " + x);

安全替换换行符的最好方法是

yourString.Replace("\r\n","\n") //handling windows linebreaks
.Replace("\r","\n")             //handling mac linebreaks

这将产生一个只有\n(如换行)作为换行符的字符串。 这段代码对于修复混合换行也很有用。

使用。net 6中的new方法

myString = myString.ReplaceLineEndings();

替换当前字符串中的所有换行序列。

文档: ReplaceLineEndings

如果你想“清除”新行，flamebaud注释使用regex @“[\r\n]+”是最好的选择。

using System;
using System.Text.RegularExpressions;

class MainClass {
  public static void Main (string[] args) {
    string str = "AAA\r\nBBB\r\n\r\n\r\nCCC\r\r\rDDD\n\n\nEEE";

    Console.WriteLine (str.Replace(System.Environment.NewLine, "-"));
    /* Result:
    AAA
    -BBB
    -
    -
    -CCC


    DDD---EEE
    */
    Console.WriteLine (Regex.Replace(str, @"\r\n?|\n", "-"));
    // Result:
    // AAA-BBB---CCC---DDD---EEE

    Console.WriteLine (Regex.Replace(str, @"[\r\n]+", "-"));
    // Result:
    // AAA-BBB-CCC-DDD-EEE
  }
}

我需要将\r\n替换为实际的回车和换行，并将\t替换为实际的制表符。所以我想到了以下几点:

public string Transform(string data)
{
    string result = data;
    char cr = (char)13;
    char lf = (char)10;
    char tab = (char)9;

    result = result.Replace("\\r", cr.ToString());
    result = result.Replace("\\n", lf.ToString());
    result = result.Replace("\\t", tab.ToString());

    return result;
}