How to unescape unicode string in C#

Question

I have a Unicode string from a text file such that. And I want to display the real character.

For example:

\u8ba1\u7b97\u673a\u2022\u7f51\u7edc\u2022\u6280\u672f\u7c7b

When read this string from text file, using StreamReader.ReadToLine(), it escape the \ to '\\' such as "\\u8ba1", which is not wanted.

It will display the Unicode string same as from text. Which I want is to display the real character.

How can change the "\\u8ba1" to "\u8ba1" in the result string.
Or should use another Reader to read the string?

possible duplicate of [Why when I read from an XML document do I get \r\r\n\n etc etc?](http://stackoverflow.com/questions/5980968/why-when-i-read-from-an-xml-document-do-i-get-r-r-n-n-etc-etc) — dtb, Dec 19 '11 at 08:22
possible duplicate of [How do convert unicode escape sequences to unicode characters in a .NET string](http://stackoverflow.com/questions/183907/how-do-convert-unicode-escape-sequences-to-unicode-characters-in-a-net-string) — dtb, Dec 19 '11 at 08:41
See my answer to this problem here: [Evaluate escaped string in C#][1] [1]: http://stackoverflow.com/questions/6629020/evaluate-escaped-string — deAtog, Jan 13 '12 at 18:04

score 26 · Answer 1 · answered Dec 19 '11 at 08:30

26

If you have a string like

var input1 = "\u8ba1\u7b97\u673a\u2022\u7f51\u7edc\u2022\u6280\u672f\u7c7b";

// input1 == "计算机•网络•技术类"

you don't need to unescape anything. It's just the string literal that contains the escape sequences, not the string itself.

If you have a string like

var input2 = @"\u8ba1\u7b97\u673a\u2022\u7f51\u7edc\u2022\u6280\u672f\u7c7b";

you can unescape it using the following regex:

var result = Regex.Replace(
    input2,
    @"\\[Uu]([0-9A-Fa-f]{4})",
    m => char.ToString(
        (char)ushort.Parse(m.Groups[1].Value, NumberStyles.AllowHexSpecifier)));

// result == "计算机•网络•技术类"

answered Dec 19 '11 at 08:30

dtb

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3

One can also use the static `Regex.Unescape`. – Oded Jan 27 '12 at 12:22
3

No, Regex.Unescape is only for Regex characters – marsze Aug 05 '15 at 06:29
Please don't use Regex.Unescape. It will do the job for the unicode escaped characters, but it will potentially also unescape other text that contains Regex-related keywords. – Mladen B. Feb 21 '18 at 15:17

rraallvv · Answer 2 · 2020-08-20T11:47:38.287

6

This question came out in the first result when googling, but I thought there should be a simpler way... this is what I ended up using:

using System.Text.RegularExpressions;

//...

var str = "Ingl\\u00e9s";
var converted = Regex.Unescape(str);
Console.WriteLine($"{converted} {str != converted}"); // Inglés True

edited Aug 20 '20 at 11:47

answered Mar 05 '18 at 19:37

rraallvv

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UrlDecode does nothing for `\u00e9`, because it is already the real character. If you apply this to the question it would be `string x = HttpUtility.UrlDecode("Ingl\\u00e9s");` which does not do anything. – Silvermind Aug 20 '20 at 11:09
1

@Silvermind good catch. Edited the answer, it should work now. – rraallvv Aug 20 '20 at 11:52

How to unescape unicode string in C#

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