how to change a line in a txt-document

Kristian Danielsson

Hi there, I'm having a problem here. I have a .txt-file where one line contains "", this is the line I wanna change. But I can't get this code to work, anyone that can help me?
I have this code here that is working for only replacing a string, but I don't know how to do it so it changes the whole line.

public void t()

{

string filename = @"F:\test\test.txt";

StringBuilder result = new StringBuilder();

if (System.IO.File.Exists(filename))

{

using (StreamReader streamReader = new StreamReader(filename))

{

String line;

while ((line = streamReader.ReadLine()) != null)

{

string newLine = String.Concat(line, Environment.NewLine);

newLine = newLine.Replace("", "HEJHEJ ");

result.Append(newLine);

}

using (FileStream fileStream = new FileStream(filename, FileMode.Open, FileAccess.ReadWrite))

{

StreamWriter streamWriter = new StreamWriter(fileStream);

streamWriter.Write(result);

streamWriter.Close();

fileStream.Close();

}

}

This code is changeing "" to "HEJHEJ", but I want to whole line in the txt-document to change to "HEJHEJ", not just only ""

4 Replies

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Kristian Danielsson14y ago
Thanks very much! It worked out perfect and i didn't have to work with FileStream and StreamWriter/StreamReader that I was trying with the first time
0
Vulpes14y ago
No problem, Kristian, just replace this line:

lines[i] = lines[i].Replace("", "HEJHEJ ");

with this:

lines[i] = "HEJHEJ";
0
Kristian Danielsson14y ago
Vulpes, your code is only replacing "message" with "HEJHEJ", I want the whole line that contains "message" to change, not just only that specific word
0
Vulpes14y ago
Try this:

public void t()
{
string filename = @"F:\test\test.txt";
if (File.Exists(filename))
{
string[] lines = File.ReadAllLines(fileName);

for(int i = 0; i < lines.Length; i++)
{
if(lines[i].Contains(""))
{
lines[i] = lines[i].Replace("", "HEJHEJ ");
break;
}
}

File.WriteAllLines(lines);
}
}
0