删除字符串的特定部分

Question

I want to go through a text file and remove specific parts of the string. In this case I want to remove the path:

PERFORMER "Charles Lloyd"

TITLE "Mirror"

FILE "Charles Lloyd\[2010] Mirror\01. I Fall In Love Too Easily.wav" WAVE

TRACK 01 AUDIO

FILE "Charles Lloyd\[2010] Mirror\02. Go Down Moses.wav" WAVE

to

PERFORMER "Charles Lloyd"

TITLE "Mirror"

FILE "01. I Fall In Love Too Easily.wav" WAVE //here are the changes

TRACK 01 AUDIO

FILE "02. Go Down Moses.wav" WAVE //here are the changes

I tried out things like: (given the string s which contains the whole text)

s = s.Remove(s.IndexOf("FILE") + 5, (s.IndexOf("\\") + 1) - s.IndexOf("FILE") - 5);

and repeat this function to remove the part between "FILE " " and the following backslash

It removes the part correctly, but I would have to manually adjust the number of times it has to run this function (run once for every backslash per line). But this algorithm lacks flexibility and I don't know how to make it approach the next line that starts with "FILE" and begin the procedure again...

Answer 1

If all your text is one string variable, you could first split it, and than do replacements for all strings and than join again (assume your text is variable lines ):

var strings = lines.Split(new[] { Environment.NewLine }, StringSplitOptions.None);
var replacedStrings = new List<string>();
foreach (var s in strings)
{       
    string replaced;
    if (s.StartsWith("FILE"))
    {
        var sWithoutFile = s.Substring(5);
        replaced = s.Substring(0, 6) +
                    sWithoutFile.Substring(sWithoutFile.LastIndexOf("\\") + 1);
    }
    else
    {
        replaced = s;
    }
    replacedStrings.Add(replaced);
}   
var result = string.Join(Environment.NewLine, replacedStrings);

Answer 2

Assuming that your line always start with FILE " and EndsWith " WAVE , you can use System.Io.Path.GetFilename() Function to achieve this:

If str.StartsWith("File"){

string strResult = "FILE """ + IO.Path.GetFileName(str.Substring(6,str.Length - 12)) + """ WAVE";

}

Example:

FILE "Charles Lloyd\[2010] Mirror\01. I Fall In Love Too Easily.wav" WAVE

Result:

FILE "01. I Fall In Love Too Easily.wav" WAVE

You can read more about this Function in this MSDN article

Answer 3

Split the array using character \\ and store the last element in the array back to the string.

For Example something like this:

array = file.split('\')

file = array[array.size - 1];

Answer 4

What about Regular Expressions.

using System;
using System.Text.RegularExpressions;

class RemovePaths
{
    static void Main()
    {
        string input = @"
PERFORMER ""Charles Lloyd""

TITLE ""Mirror""

FILE ""Charles Lloyd\[2010] Mirror\01. I Fall In Love Too Easily.wav"" WAVE

TRACK 01 AUDIO

FILE ""Charles Lloyd\[2010] Mirror\02. Go Down Moses.wav"" WAVE";

        string test = @"
PERFORMER ""Charles Lloyd""

TITLE ""Mirror""

FILE ""01. I Fall In Love Too Easily.wav"" WAVE

TRACK 01 AUDIO

FILE ""02. Go Down Moses.wav"" WAVE";

        Regex rgx = new Regex(@"(?<=\"").*\\(?=.+\"")");
        string result = rgx.Replace(input, "");
        Console.WriteLine(result == test ? "Pass" : "Fail");
    }
}

Breakdown of the RegEx...

(?<=\\"") <--- must start with a double-quote but be excluded using (?<=...)

. \\ <--- match any text up to and including a "\\". note: . matches anything

(?=.+\\"") <--- skip at least one character(.+) and it must end with a double-quote(\\").