MessageBox的Buttons和三级联动效果

DialogResult dr = MessageBox.Show("是否要继续吗？", "警告！！！", MessageBoxButtons.OKCancel);//它弹出的对话框如下图所示if (dr == DialogResult.OK)//只有按下确定按钮才执行下面{label1.Text = "天气不错";}

public Form1()// Form1的构造函数{InitializeComponent();AreaDataBind(comboBox1, "0001");AreaDataBind(comboBox2, comboBox1.SelectedValue.ToString());AreaDataBind(comboBox3, comboBox2.SelectedValue.ToString());}public void AreaDataBind(ComboBox cb, string Pcode){cb.DataSource = new ChinaData().Select(Pcode);//数据源cb.DisplayMember = "AreaName";//显示值cb.ValueMember = "AreaCode";//实际值}private void comboBox1_SelectedIndexChanged(object sender, EventArgs e){AreaDataBind(comboBox2, comboBox1.SelectedValue.ToString());}private void comboBox2_SelectedIndexChanged(object sender, EventArgs e){AreaDataBind(comboBox3, comboBox2.SelectedValue.ToString());}