C# 弹出窗口show()和showdialog()的两种方式

        public Form1()
        {
            InitializeComponent();            
        }        
        //实例化窗口类
        Dialog _dlg = new Dialog();

        private void button_show_Click(object sender, EventArgs e)
        {           
            _dlg.Show();//显示
        }

        private void button_hide_Click(object sender, EventArgs e)
        {          
            _dlg.Hide();//隐藏
        }
        
        private void button_showDialog_Click(object sender, EventArgs e)
        {
            //实例化窗口类
            Dialog _dialog = new Dialog();
            //弹出对话框
            _dialog.ShowDialog();
        }

  		public Dialog()
        {
            InitializeComponent();
        }

        private void button_ok_Click(object sender, EventArgs e)
        {
            //指定返回结果
            this.DialogResult = DialogResult.OK;
            //关闭
            this.Close();
        }

        private void button_cancel_Click(object sender, EventArgs e)
        {
        	//指定返回结果
            this.DialogResult = DialogResult.Cancel;
            //关闭
            this.Close();
        }

        private void hide_Click(object sender, EventArgs e)
        {
            //隐藏
            this.Hide();
        }