Question

I am building a WinForms application that receives a path from a user via a SaveFileDialog.

Here is the relevant portion of my code. How can I determine if the path pcapFile is valid and exists?

private void btnBrowse_Click(object sender, EventArgs e)
{
    SaveFileDialog saveFileDialogBrowse = new SaveFileDialog();
    saveFileDialogBrowse.Filter = "Pcap file|*.pcap";
    saveFileDialogBrowse.Title = "Save an pcap File";
    saveFileDialogBrowse.ShowDialog();
    pcapFile = saveFileDialogBrowse.FileName; //do whatever you like with the selected filename

    if (pcapFile != "")
    {
        FileInfo fileInfo = new FileInfo(pcapFile);
        tbOutputFileName.Text = fileInfo.FullName;
    }
}

Answer 1

FileInfo will throw an exception if the path provided to it is malformed. If you want to know if that file already exists check the FileInfo.Exists property.