前台DropDownList动态取得值 ，后台无法获取SelectedValue
前台    
  <asp:TableRow Height="25">
 <asp:TableCell ID="TableCell8"  Text="分类：" />
<asp:TableCell ID="TableCell16" cssClass="tb_edit_text" >
 <asp:DropDownList ID="feilei" AutoPostBack="true" runat="server" DataSourceID="SqlDataSource1" DataTextField="feilei" DataValueField="feilei" onselectedindexchanged="DropDownList1_SelectedIndexChanged"></asp:DropDownList>
<asp:SqlDataSource ID="SqlDataSource1" runat="server" ConnectionString="<%$ ConnectionStrings:waternewsConnectionString %>" SelectCommand="select feilei from jcsj group by feilei"></asp:SqlDataSource>
 </asp:TableCell> 
</asp:TableRow>

后台
 protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
    {

                 string  feilei = feilei.SelectedValue;//这句有错
..........
}
------解决方案--------------------
局部变量的名字和你的DropDownList的ID重名 导致编译器认为feilei.SelectedValue是前面声明的局部变量的 所以报错了 换个命名就好了

string  feilei = feilei.SelectedValue;