private void WorkflowConfigure_FormClosing(object sender, FormClosingEventArgs e)
        {

            DialogResult result = MessageBox.Show("此操作会丢弃您的当前设置，确定要继续？", "退出", MessageBoxButtons.YesNo, MessageBoxIcon.Question);

 

            if (DialogResult.Yes == result)
            {
                e.Cancel = false;   // Cancel属性如果为true，表示取消该事件的执行。
            }
            else
            {
                e.Cancel = true;
            }
        }