Question

In my case the SaveFileDialog will not write any file, but I want to use to specify the path for a command line app which will create the logfile on the same location as “saved” in the sf dialog.

SaveFileDialog sfd = new SaveFileDialog();
sfd.Filter = "*.txt";
string sfdname = saveFileDialog1.FileName;
if (sfd.ShowDialog() == DialogResult.OK)
{
  Path.GetFileName(sfd.FileName);
}

startInfo.Arguments = "--log=" + Path.GetFileName(sfd.FileName);

Answer 1

Just remove the Path.GetFileName:

startInfo.Arguments = "--log=\"" + sfd.FileName + "\"";