Save File Dialog , restrict name

Question

my program has a save file option which is shown below :

        //Browse for file
        SaveFileDialog ofd = new SaveFileDialog();
        ofd.Filter = "CSV|*.csv";
        ofd.DefaultExt = ".csv";

        DialogResult result = ofd.ShowDialog();
        string converted = result.ToString();

        if (converted == "OK")
        {
            Master_Inventory_Export_savePath.Text = ofd.FileName;
        }

if I write the file name as "example" it saves correctly as a .csv however if I set the name as "example.txt" it saves as a text file , I've looked on msdn etc but even setting the default extension doesn't prevent this , any ideas on how to only allow files of .csv to be saved ?

Answer 1

You could use the FileOk event to check what your users type and refuse the input if they type something that you don't like.

For example:

SaveFileDialog sdlg = new SaveFileDialog();
sdlg.FileOk += CheckIfFileHasCorrectExtension;
sdlg.Filter = "CSV Files (*.csv)|*.csv";
if(sdlg.ShowDialog() == DialogResult.OK)
    Console.WriteLine("Save file:" + sdlg.FileName);

 void CheckIfFileHasCorrectExtension(object sender, CancelEventArgs e)
 {
     SaveFileDialog sv = (sender as SaveFileDialog);
     if(Path.GetExtension(sv.FileName).ToLower() != ".csv")
     {
         e.Cancel = true;
         MessageBox.Show("Please omit the extension or use 'CSV'");
         return;
     }
 }

The main advantage of this approach is that your SaveFileDialog is not dismissed and you could check the input without reloading the SaveFileDialog if something is wrong.

BEWARE the SaveFileDialog appends automatically your extension if it doesn't recognize the extension typed by your users. This means that if your users type somefile.doc then the SaveFileDialog doesn't append the .CSV extension because the .DOC extension is well known in the OS. But if your users type somefile.zxc then you receive as output (and also in the FileOk event) a FileName called somefile.zxc.csv