C# \b 未找到

Question

        Match m = Regex.Match(richText, "\\\\par\b", RegexOptions.None);
        richText = Regex.Replace(richText, "\\\\par\b", "", RegexOptions.IgnoreCase);

Input:

"{\\rtf1\\ansi\\ansicpg1252\\deff0\\deflang1033{\\fonttbl{\\f0\\fnil Arial;}{\\f1\\fnil\\fcharset0 Microsoft Sans Serif;}}\\viewkind4\\uc1\\pard\\f0\\fs20 CC: not specified\\f1\\fs17\\par}"

I'd like it to find the \\par only, and not the \\pard that can be found in the middle of the input.

Answer 1

Backslashes are escape characters in both string literals and regexes, so when you have a regex in a string literal you need to either double the backslashes or prefix the string literal with @ .

You're not doubling for the \b , so it's a backspace character.

Answer 2

MRAB is correct:

[TestClass]
public class UnitTest1
{
    [TestMethod]
    public void TestWithDoubleBackslash()
    {
        const string regex1 = "\\\\par\\b";
        TestRegEx(regex1);
    }

    [TestMethod]
    public void TestWithSingleBackslash()
    {
        const string regex2 = "\\\\par\b";
        TestRegEx(regex2);
    }

    private static void TestRegEx(string regex)
    {
        var richText =
            "{\\rtf1\\ansi\\ansicpg1252\\deff0\\deflang1033{\\fonttbl{\\f0\\fnil Arial;}{\\f1\\fnil\\fcharset0 Microsoft Sans Serif;}}\\viewkind4\\uc1\\pard\\f0\\fs20 CC: not specified\\f1\\fs17\\par}";
        Match m = Regex.Match(richText, regex, RegexOptions.None);
        var output = Regex.Replace(richText, regex, "", RegexOptions.IgnoreCase);

        Console.WriteLine("BEFORE : [" + richText + "]");
        Console.WriteLine("AFTER  : [" + output + "]");

        Assert.IsTrue(output.Contains("pard"));
        Assert.IsFalse(output.Contains("fs17\\par"));
    }
}