Question

C# DropDownList控件的OnSelectedIndexChanged获取值问题！

aspx文件：
....<asp:DropDownList ID="ddlCondition" runat="server" OnSelectedIndexChanged="loadselected" AutoPostBack=true></asp:DropDownList>....

cs文件
......DataSet btypeds = btypemanage.GetAllBType("tb_booktype");
ddlCondition.DataSource = btypeds;
ddlCondition.DataTextField = "typename";
ddlCondition.DataBind();
//这里绑定数据可以实现！
......
public void loadselected(object sender, EventArgs e)
{
bookmanage.Type = ddlCondition.SelectedValue;
Response.Write("<script>alert('" + bookmanage.Type + ddlCondition.SelectedItem + ddlCondition.SelectedIndex + "')</script>");
//这里出问题！无论我下拉列表选的是什么，这里的弹出框输出的全是第一个option的内容。不知道是什么问题请各位指点。
......}

Answer 1

protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack) //首次进来帮顶5个值
{
DropDownList1.Items.Add(new ListItem(1.ToString()));
DropDownList1.Items.Add(new ListItem(2.ToString()));
DropDownList1.Items.Add(new ListItem(3.ToString()));
DropDownList1.Items.Add(new ListItem(4.ToString()));
DropDownList1.Items.Add(new ListItem(5.ToString()));
}
}

protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
{
//获取当前选中下标的值
Response.Write("<script>alert('" + this.DropDownList1.SelectedValue + "')</script>");
}

我测试了下，貌似没问题

Answer 2

一楼正确。
貌似是绑定数据没有放到 if (!IsPostBack) 里吧

Answer 3

取值：this.DropDownList1.SelectedItem.ToString()，这样就可以取得所选的值了