Dropdownlist控件属性 OnSelectedIndexChanged方法不触发

<asp:DropDownList ID="ddlWJLX" runat="server" OnSelectedIndexChanged="ddlWJLX_SelectedIndexChanged">
</asp:DropDownList>

解决方案：

1. AutoPostBack="true"

<asp:DropDownList ID="ddlWJLX" runat="server" OnSelectedIndexChanged="ddlWJLX_SelectedIndexChanged" AutoPostBack="true">
</asp:DropDownList>