Question

I have a Form_Closing event that prompts the user if the file has been changed to save if changes have been made to the file (standard Yes/No/Cancel options). Cancel is where things don’t work as they should.

If I select File -> New and there is an existing file with changes I get prompted as expected, bit when I select Cancel the new form is presented rather than staying on the current form and I end up with two forms open at once.

Here is MainForm (File New) code:

       if (editForm != null)
        {
            // Close existing Editor form
            editForm.Close();
            // Open new form
            editForm = new EditorForm(this);
            // Close Form Events
            editForm.Closing += new CancelEventHandler(EditorForm_Closing);
            editForm.Show();
            editForm.Focus();

      else
        {
            // Open new Editor 
            editForm = new EditorForm(this);
            // Close Form Events
            editForm.Closing += new CancelEventHandler(EditorForm_Closing);
            editForm.Show();
            editForm.Focus();
        }

Here is my EditForm_Closing:

  if (editForm != null)
        {
            if (editForm.diagramComponent.Model.Modified)
            {
                DialogResult res = MessageBox.Show(this, "The project has been modified. Save changes?", "Save changes", MessageBoxButtons.YesNoCancel);
                if (res == DialogResult.Yes)
                {
                    if (!editForm.HasFileName)
                    {
                        if (this.saveEditorDialog1.ShowDialog(this) == DialogResult.OK)
                        {
                            this.ActiveDiagram.SaveSoap(this.saveEditorDialog1.FileName);
                            editForm.FileName = this.saveEditorDialog1.FileName;
                        }
                    }
                    else
                    {
                        this.ActiveDiagram.SaveSoap(editForm.FileName);
                    }

                }
                else if (res == DialogResult.Cancel)
                {
                    e.Cancel = true;
                }
            }

Not sure how to make the correlation between the Cancel close event and my File -> New. Any help is greatly appreciated. Thank you.

EDIT: Added my EditForm_Closing Event.

Answer 1

Try replacing your main form’s code with the following:

if (editForm != null) {
    // try closing existing Editor form
    editForm.Close();
    if(!editForm.IsDisposed) // close was canceled.
        return;
}

// Open new form
editForm = new EditorForm(this);
// Close Form Events
editForm.FormClosing += new FormClosingEventHandler('suitable method here');
editForm.Show();
editForm.Focus();