Question

I have a MainForm. I can close it by using a close button (upper right corner) or by clicking a menuitem miExit.

My problem is when I clicked miExit and answered “OK”, it shows messageBox TWICE. How can I fix it ? (I understand why it shows twice but how can I avoid it ?)

Both formclosing and miExit clicks must provide messagebox with “Exit ?” prompt.

partial class MainForm : Form
{
    void MainForm_FormClosing(object sender, FormClosingEventArgs e)
    {
        DialogResult dr = MessageBox.Show("Exit ?", "Exit", MessageBoxButtons.OKCancel,         MessageBoxIcon.Question);

        if (dr == DialogResult.OK)
        {
            SaveSettings();
        }
        else
        {
            e.Cancel = true;
        }
    }

    void miExit_Click(object sender, EventArgs e)
    {
        DialogResult dr = MessageBox.Show("Exit ?", "Exit", MessageBoxButtons.OKCancel,             MessageBoxIcon.Question);

        if (dr == DialogResult.OK)
        {
    SaveSettings();

            Application.Exit();
        }
    }

    void SaveSettings()
    {
    // save user settings to file ...
    }
}

Answer 1

Change the miExit_Click handlier to just call Application.Exit()

Application.Exit() automatically calls the FormClosing event on all open forms. And yes, these forms can cancel the Exit by setting their FormClosingEventArgs‘s Cancel property to true.

P.S. If you don’t believe me, I linked to the documentation for Application.Exit(), the FormClosing bit is the first bullet point under Remarks.