Question

The following code is used to save a CSV string, however, if I save to an existing .CSV, instead of replacing the data, it only adds the new string to the data already there.
How do I remedy this? Is it something inherent to how the Stream.Write function works, or is this an idiosyncrasy of Excel and .CSV?

SaveFileDialog dialog = new SaveFileDialog();

dialog.AddExtension = true;
dialog.Filter = "CSV Files (*.csv)|*.csv|All Files (*.*)|*.*";
dialog.FilterIndex = 1;
dialog.Title = "Save As";
dialog.InitialDirectory = "C:\\";
dialog.CheckPathExists = true;
dialog.DefaultExt = ".csv";
dialog.ValidateNames = true;

if (dialog.ShowDialog() == DialogResult.OK)
{
    StreamWriter myStream = new StreamWriter(dialog.FileName, true);
    myStream.Write(//Function which returns a CSV-formmatted string//);
    myStream.Close();
    OpenFile(dialog.FileName);
}

Answer 1

StreamWriter myStream = new StreamWriter(dialog.FileName, false);

http://msdn.microsoft.com/library/36b035cb%28v=vs.100%29

the second parameter (bool append), is well described :

append
Type: System.Boolean
Determines whether data is to be appended to the file. If the file exists and append is false, the file is overwritten. If the file
exists and append is true, the data is appended to the file.
Otherwise, a new file is created.