ListBox1控件

前台：

  <div>
        <asp:ListBox ID="ListBox1" runat="server" AutoPostBack="True" Height="66px" OnSelectedIndexChanged="ListBox1_SelectedIndexChanged1" Width="80px">
            <asp:ListItem>1</asp:ListItem>
            <asp:ListItem>2</asp:ListItem>
            <asp:ListItem>3</asp:ListItem>
            <asp:ListItem>4</asp:ListItem>
        </asp:ListBox>
        <asp:Label ID="Label1" runat="server"></asp:Label>
    </div>

后台

第一种foreach循环

protected void ListBox1_SelectedIndexChanged1(object sender, EventArgs e)
    {

        string strHobby = "";
        foreach (ListItem item in ListBox1.Items)
        {


            if (item.Selected)
            {
                strHobby += item.Value + "";


            }
        }


        Label1.Text = strHobby;
    }

 for循环

    protected void ListBox1_SelectedIndexChanged1(object sender, EventArgs e)
    {
        string strHobby = "";
        for (int i = 0; i < ListBox1.Items.Count; i++)
        {
            if (ListBox1.Items[i].Selected)
            {
                strHobby += ListBox1.Items[i].Value ;
            }
        }
        Label1.Text = strHobby;
    }