新手问问题:关于ComboBox!

Question

现在有两个ComboBox1和ComboBox2,ComboBox1里面有两个选项A和B,选中A,则ComboBox2里显示a,b,c这3个选项,选中B,则ComboBox2里面显示d,e,f这3个选项。现在的问题是，例如当选种ComboBox1里面的A和ComboBox2里面的c后，如果要改选ComboBox1里的B，怎样可以让程序自动清除停留在ComboBox2里的c项目？
请大家帮忙，谢谢！！！

Answer 1

在SelectIndexChanged()中写comboBox1.Items.Remove等

Answer 2

能说得具体一点吗???我的代码是这样的,非常谢谢!!!
private void comboBox1_SelectedIndexChanged(object sender, System.EventArgs e)
{
    
comboBox2.Items.Clear();
switch(comboBox1.Text)
{
case"A":
comboBox2.Items.Add("a");
comboBox2.Items.Add("b");
                                     comboBox2.Items.Add("c");
break;
case"B":
comboBox2.Items.Add("d");
comboBox2.Items.Add("e");
comboBox2.Items.Add("f");
}
}

Answer 3

private void Form1_Load(object sender, EventArgs e)
       {
           comboBox1.Items.Add("A");
           comboBox1.Items.Add("B");
           comboBox2.Items.Add("a");
           comboBox2.Items.Add("b");
           comboBox2.Items.Add("c");       }       private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
       {
           comboBox2.Items.Clear();
           switch (comboBox1.SelectedItem.ToString())
           {
               case "A":
                   comboBox2.Items.Add("a");
                   comboBox2.Items.Add("b");
                   comboBox2.Items.Add("c");
                   comboBox2.SelectedIndex = 0;
                   break;
               case "B":                  
                   comboBox2.Items.Add("d");
                   comboBox2.Items.Add("e");
                   comboBox2.Items.Add("f");
                   comboBox2.SelectedIndex = 0;
                   break;
           }
       }
我试过了，你可以查MSDN