我在代码隐藏中生成一个下拉列表,无法让 selectedindexchanged 事件自动触发。直接放入 ASPX 页面时它工作正常,但我需要它在代码隐藏中。
这不起作用:
var deptList = new DropDownList
{
ID = "deptList",
DataSource = departments,
DataTextField = "deptname",
DataValueField = "deptid",
AutoPostBack = true,
EnableViewState = true
};
deptList.SelectedIndexChanged += new EventHandler(deptList_SelectedIndexChanged);
deptList.DataSource = departments;
deptList.DataTextField = "deptname";
deptList.DataValueField = "deptid";
if (!IsPostBack)
deptList.DataBind();
deptList.Items.Insert(0, new ListItem("---Select Department---", string.Empty));
writer.Write("Select a department: ");
deptList.RenderControl(writer);
但这有效:
<asp:DropDownList ID="deptList" AutoPostBack="true" runat="server" OnSelectedIndexChanged="deptList_SelectedIndexChanged"></asp:DropDownList>