Exception when a path to a file is null (when you cancel OpenFiledDalog)

Question

This is the code:

OpenFileDialog openFileDialog1 = new OpenFileDialog();

        DialogResult result = openFileDialog1.ShowDialog(); // Show the dialog.
        if (result == DialogResult.OK) // Test result.
        {
            string file = openFileDialog1.FileName;

        }
        else { MessageBox.Show("Error."); }

//later on..
        DataTable lertableEC0 = new DataTable();
        lertableEC0.ReadXml(openFileDialog1.FileName);

and right here in the end comes the error, everything works fine, the xml import, etc only if i cancel in the open dialog i get the exception, any hint?

(there ir a similar question but the answer is still very confusing for me

  return null;    

didnt work for me

Answer 1

  if (result == DialogResult.OK) // Test result.
  {
        string file = openFileDialog1.FileName;

        DataTable lertableEC0 = new DataTable();
        lertableEC0.ReadXml(openFileDialog1.FileName);       
  }
 else { 
       MessageBox.Show("Error.");
  }

Since filename is not set if Cancel button is clicked , empty string is passed to ReadXml() function which throws exception . So you have to move the function inside OK click condition