Editing/Deleting lines in files in Windows Phone 8.1 C#

Question

I'm accessing files in LocalFolder with structure:

1,Name1,SomeOtherProperty1
2,Name2,SomeOtherProperty2

using Streams to write and read specyfic lines:

        public async void saveToFile(List<string> content, string fileName) {

        using (StreamWriter writeStream = new StreamWriter(await localFolder.OpenStreamForWriteAsync(fileName, CreationCollisionOption.OpenIfExists))) {
            foreach (string contentLine in content) {
                await writeStream.WriteLineAsync(contentLine);
            }
            writeStream.Dispose();
        }
    }

But as far as I know there is no option to edit or delete only n line. Do you have any sugestions?

Answer 1

This one is dirty, but works for small files.

    public async void editLineById(string fileName, string match, string content) {
        List<string> file = await readAllFromFile(fileName);
        int matchId = file.IndexOf(file.Where((item) => item.Contains(match)).First());
        file[matchId] = content;
        overrideFile(fileName, file);
    }

    public async Task<List<string>> readAllFromFile(string fileName) {
            List<string> content = new List<string>();
            using (StreamReader readStream = new StreamReader(await localFolder.OpenStreamForReadAsync(fileName))) {
                while (readStream.Peek() != -1) {
                    content.Add(await readStream.ReadLineAsync());
                }
                readStream.Dispose();
            }
        return content;
    }

    public async void overrideFile(string fileName, List<string> content) {
        using (StreamWriter writeStream = new StreamWriter(await localFolder.OpenStreamForWriteAsync(fileName, CreationCollisionOption.ReplaceExisting))) {
            foreach(string line in content) {
                await writeStream.WriteLineAsync(line);
            }
        }
    }