File.ReadLines keeps file locked after reading it and i can't write into it - file

Question

For some reason File.ReadLines keeps the file that im reading locked, and when i am trying to write text into it using a streamWriter, i get an error that it is being used by another process. If i don't read it first, writing into it works fine. Here is my code:
IEnumerable<String> lines;
private void loadCfg()
{
lines = File.ReadLines(Application.StartupPath + #"\server.cfg");
foreach (var line in lines)
{
if (line.Contains("Port"))
{
portTxtBox.Text = extractValue(line);
}
if (line.Contains("Cars"))
{
maxCarsCombo.Text = extractValue(line);
}
if (line.Contains("MaxPlayers"))
{
maxPlayerCombo.Text = extractValue(line);
}
}
}
private void saveBtn_Click(object sender, EventArgs e)
{
StreamWriter sw = new StreamWriter(Application.StartupPath + #"\server.cfg",false);
sw.WriteLine(lines.ElementAt(0));
sw.Close();
}

Answer 1

Well you should read all the lines using StreamReader class that way your file will be properly closed I altered the way you are reading lines to read all lines using StreamReader try the following version
List<string> lines = new List<string>()
private void loadCfg()
{
string temp = null;
StreamReader rd = new StreamReader(Application.StartupPath + #"\server.cfg");
temp = rd.ReadLine();
while(temp != null)
{
lines.Add(temp);
temp = rd.ReadLine();
}
rd.Close();
foreach (var line in lines)
{
if (line.Contains("Port"))
{
portTxtBox.Text = extractValue(line);
}
if (line.Contains("Cars"))
{
maxCarsCombo.Text = extractValue(line);
}
if (line.Contains("MaxPlayers"))
{
maxPlayerCombo.Text = extractValue(line);
}
}
}
private void saveBtn_Click(object sender, EventArgs e)
{
StreamWriter sw = new StreamWriter(Application.StartupPath + #"\server.cfg",false);
sw.WriteLine(lines.ElementAt(0));
sw.Close();
}
I have not tested the code but I am sure it will solve your problem