private void button2_Click(object sender, EventArgs e) { Class3 parent; Class4 c4 = new Class4(); parent = c4; //上溯造型,父类(接口)变量指向子类对象。 MessageBox.Show(parent.GetString()); Class5 c5 = new Class5(); parent = c5; //上溯造型,父类(接口)变量指向子类对象。 MessageBox.Show(parent.GetString()); }
private void button9_Click(object sender, EventArgs e) { OOHandler o = new OOHandler(); Class3 parent; parent = new Class4(); this.textBox1.Text = o.HandleParentObject(parent); parent = new Class5(); this.textBox2.Text = o.HandleParentObject(parent); }