Gridview控件绑定DropDownlist

Question

请帮我这个。我在我的页面上有一个包含2个下拉列表（大学和学院）的GridView控件。大学约在page_load事件，而大学取决于Uninversity.selectedValue。我有一个添加按钮，将新行添加到网格中。

问题是有超过1行时。我无法确定哪个大学在onselectedIndexChanged赛事上具有约束力。它不断绑定第一排学院。

这是我在我的SelectedIndexChanged方法

protected void drpUniversityName_SelectedIndexChanged(object sender, EventArgs e) 
    { 
     GridViewRowEventArgs e1 = (GridViewRowEventArgs)e; // Gives me a casting error on this line 
     DropDownList drpUniversityName = (DropDownList)(e1.Row.FindControl("drpUniversityName")); 
     DropDownList drpCollegeName = (DropDownList)(e1.Row.FindControl("drpCollegeName")); 
     bindColleges(drpUniversityName,drpCollegeName); 
    } 

迄今所做的，我需要一些方法来获取当前行的大学和学院。

Answer 1

<asp:GridView ID="GridView1" runat="server" > 
      <Columns> 
       <asp:TemplateField> 
        <ItemTemplate> 
         <asp:DropDownList ID="ddlUniversity" runat="server" AutoPostBack="True" 
          onselectedindexchanged="ddlUniversity_SelectedIndexChanged"> 
          <asp:ListItem>1</asp:ListItem> 
          <asp:ListItem>2</asp:ListItem> 
          <asp:ListItem>3</asp:ListItem> 
         </asp:DropDownList> 
        </ItemTemplate> 
       </asp:TemplateField> 
       <asp:TemplateField> 
        <ItemTemplate> 
         <asp:DropDownList ID="ddlCollege" runat="server"> 
         </asp:DropDownList> 
        </ItemTemplate> 
       </asp:TemplateField> 
      </Columns> 
     </asp:GridView> 

，这里是C＃代码：

protected void Page_Load(object sender, EventArgs e) 
    { 
     if (!IsPostBack) 
      GridView_DataBind(); 
    } 

    private void GridView_DataBind() 
    { 
     string[] datasource = { "1", "2", "3" }; 

     GridView1.DataSource = datasource; 
     GridView1.DataBind(); 
    } 

    protected void ddlUniversity_SelectedIndexChanged(object sender, EventArgs e) 
    { 
     GridViewRow currentRow = (GridViewRow)((Control)sender).NamingContainer; 

     //your code here 
    }