Append text at a certain row in a txt-file

[korven]

Hi.

I'm trying to append text to a txt file at a certain row.
For example:
a
b
c
d

And after I run the program and append 'z' at row 3, it should look like:
a
b
cz
d

Does anyone know how to do this? I can't seem to get append to work, only overwriting.

[wild_bill]

		private void button1_Click(object sender, System.EventArgs e)
		{
			System.Text.StringBuilder buffer = new System.Text.StringBuilder();
			System.IO.StreamReader reader = System.IO.File.OpenText("C:\\Temp\\New Text Document.txt");
			Int32 lineCount = 1;

			while (reader.Peek() != -1)
			{
				if (lineCount == 3)
				{
					buffer.Append(reader.ReadLine());
					buffer.Append("z");
				}
				else
				{
					buffer.Append(reader.ReadLine());
				}
				buffer.Append(Environment.NewLine);
				lineCount++;
			}
			reader.Close();

			System.IO.StreamWriter writer = new System.IO.StreamWriter("C:\\Temp\\New Text Document.txt",false);
			writer.Write(buffer.ToString());
			writer.Flush();
			writer.Close();
        }

[korven]

Works great!
Thanks a lot!

[basti42]

these codes works
private void button1_Click(object sender, System.EventArgs e)
{
System.Text.StringBuilder buffer = new System.Text.StringBuilder();
System.IO.StreamReader reader = System.IO.File.OpenText("C:\\Temp\\New Text Document.txt");
Int32 lineCount = 1;

while (reader.Peek() != -1)
{
if (lineCount == 3)
{
buffer.Append(reader.ReadLine());
buffer.Append("z");
}
else
{
buffer.Append(reader.ReadLine());
}
buffer.Append(Environment.NewLine);
lineCount++;
}
reader.Close();

System.IO.StreamWriter writer = new System.IO.StreamWriter("C:\\Temp\\New Text Document.txt",false);
writer.Write(buffer.ToString());
writer.Flush();
writer.Close();
}

but how if i would like these output?
a b c d
1 1 1 1
2 2 2 2
3 3 3 3
4 4 4 4

tnx

[wild_bill]

private void button1_Click(object sender, System.EventArgs e)
{

	string myPath = "C:\\New Text Document.txt";
	if (! System.IO.File.Exists(myPath))
	{
		WriteData(string.Empty,myPath);
	}

	System.Text.StringBuilder buffer = new System.Text.StringBuilder();
	System.IO.StreamReader reader = System.IO.File.OpenText(myPath);
	bool firstLine = true;

    while (reader.Peek() != -1)
	{
		string currentLine = reader.ReadLine();
					char lastChar = Convert.ToChar(currentLine.Substring(currentLine.Length - 1));
		
		if (firstLine)
		{
			lastChar = (char)(lastChar + 1);
			firstLine = false;
		}

		buffer.Append(currentLine);
		buffer.Append(" ");
		buffer.Append(lastChar);
		buffer.Append(Environment.NewLine);
	}
	reader.Close();

	//handle the first write
	if (firstLine)
	{
		buffer.Append("a");
		buffer.Append(Environment.NewLine);
		for (int i = 1; i <= 4; i++)
		{
			buffer.Append(i.ToString());
			buffer.Append(Environment.NewLine);
		}
	}
	WriteData(buffer.ToString().TrimEnd(),myPath);
}

private void WriteData(string data,string path)
{
	System.IO.StreamWriter writer = new System.IO.StreamWriter(path,false);
	writer.Write(data);
	writer.Flush();
	writer.Close();
}

[basti42]

FileStream stmRecords = new FileStream(@"C:\Scanned.txt", FileMode.Append, FileAccess.Write, FileShare.None);
StreamWriter stmWriter = new StreamWriter(stmRecords);

stmWriter.WriteLine(var1 + " , " + var2);

stmWriter.Flush();
stmWriter.Close();


tnx for ur reply but this is what i searched. it's kinda easy to understand.
except the stmWriter.Flush(); i don't jknow its function.
but if someone has the same problem above code will do.