winform程序关闭界面时弹出提示框

void Form1_FormClosing(object sender, FormClosingEventArgs e)
{
    if (MessageBox.Show(
            "窗口关闭后，数据即将丢失！是否现在关闭窗口",
            "提示", 
            MessageBoxButtons.OKCancel, 
            MessageBoxIcon.Question) != DialogResult.OK)
            {
                e.Cancel = true;
                return;
            }
}