关闭窗口前提示

    private void Form1_FormClosing(object sender,FormClosingEventArgs e)

        {

            if (MessageBox.Show("Close without save?","Confirm Message", MessageBoxButtons.OKCancel, MessageBoxIcon.Question,MessageBoxDefaultButton.Button2) == DialogResult.OK)

            {

                e.Cancel = false;

            }

            else

            {

                e.Cancel = true;

            }

       }