DropDownList操作;ListBox操作;动态创建控件;Response.Write(

1   DropDownList操作;

2   ListBox操作;

3   动态创建控件;

4   Response.Write("欢迎学习ASP.NET''!");

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1   DropDownList操作;(向右选择,向上移,向下移选项;)

if(DropDown1.Items.Count > 1)

   {

    ListItem Item = DropDown1.SelectedItem;

    DropDown1.Items.Remove(Item);

    String val = DropDown1.SelectedItem.Value ;

    String text = DropDown1.SelectedItem.Text;

    Label1.Text = val + text;

   }

   else

    DropDown1.Items.Clear();

    Label1.Text = "";

2   ListBox操作;(向右选择,向上移,向下移选项;)

private void Movebtn_Click(object sender, System.EventArgs e)

  {  

   int Count = ListBox1.Items.Count;

   int Index = 0;

   for(int i=0;i<Count-1;i++)

    ListItem Item = ListBox1.Items[Index];

    if(ListBox1.Items[Index].Selected == true)

    {

     ListBox1.Items.Remove(Item);

     ListBox2.Items.Add(Item);

     Index--;

    }

    Index++;

  }

  private void Upbtn_Click(object sender, System.EventArgs e)

  {

   //若不是第一行则上移

   if( ListBox1.SelectedIndex > 0 )

    string name = ListBox1.SelectedItem.Text;

    string ID = ListBox1.SelectedItem.Value;

    int index = ListBox1.SelectedIndex;

    ListBox1.SelectedItem.Text = ListBox1.Items[index-1].Text;

    ListBox1.SelectedItem.Value = ListBox1.Items[index-1].Value;

    ListBox1.Items[index-1].Text = name;

    ListBox1.Items[index-1].Value = ID;

    ListBox1.SelectedIndex --;

  private void Downbtn_Click(object sender, System.EventArgs e)

   //若不是最后一行则下移

   if( ListBox1.SelectedIndex >= 0 && ListBox1.SelectedIndex < ListBox1.Items.Count-1 )

    ListBox1.SelectedItem.Text = ListBox1.Items[index+1].Text;

    ListBox1.SelectedItem.Value = ListBox1.Items[index+1].Value;

    ListBox1.Items[index+1].Text = name;

    ListBox1.Items[index+1].Value = ID;

    ListBox1.SelectedIndex ++;

private void Addbtn_Click(object sender, System.EventArgs e)

  {   

   DropDownList DropDown = new DropDownList();

   PlaceHolder1.Controls.Clear();

   PlaceHolder1.Controls.Add(DropDown);

   DropDown.ID="ControlID";

   DropDown.Width=200;

   DropDown.Items.Add(new ListItem("北京","0"));

   DropDown.Items.Add(new ListItem("上海","1"));

   DropDown.Items.Add(new ListItem("河北","2"));

   ViewState["AddControl"] = true;