为什么不是SelectedIndexChanged事件从一个DropDownList在GridView闪光？ [英] Why isn't the SelectedIndexChanged event firing from a dropdownlist in a GridView?

问题描述

我不能让我的我的DropDownList火的的SelectedIndexChanged。我有以下几点：

I cannot get my SelectedIndexChanged of my dropdownlist to fire. I have the following:

<form id="form1" runat="server">
<div>
<asp:GridView id="grdPoll" runat="server" AutoGenerateColumns="false">
    <Columns>
        <asp:TemplateField>
            <ItemTemplate>
                <asp:DropDownList ID="DropDownList1" runat="server" 
                 AutoPostBack="true"
                 OnSelectedIndexChanged="DropDownList1_SelectedIndexChanged">
                    <asp:ListItem Text="Review" Value="Review" Selected="True">Review</asp:ListItem>
                    <asp:ListItem Text="Level1" Value="lvl1">Send Back to Level1</asp:ListItem>
    			</asp:DropDownList>
    		</ItemTemplate>
    	</asp:TemplateField>
    </Columns>
</asp:GridView>

<asp:Label ID="lblCity" runat="server" Text="Label"></asp:Label>  
</div>
</form>

在我的code后面我有这样的：

In my code behind I have this:

protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
{
    this.lblCity.Text = ((DropDownList)sender).SelectedValue;
}

如果我把这个相同的DDL以外的GridView的，它将触发。

If I put this same ddl outside of the gridview, it fires.

在回发发生，将AutoPostBack设置为true。本次活动只是永远不会触发。为什么我不能让我的事件在GridView内火？

The postback is occurring and the autopostback is set to true. The event just never fires. Why can't I get my event to fire from within the gridview?

感谢你。

推荐答案

嗯，这个问题被问个多月前，现在可能无关紧要，但@LFSR还跟最近编辑它，它在活动的问题。

Well, this question was asked more than a month ago and may be irrelevant now, but @LFSR was kind enough to edit it recently, it's in the "Active questions" list.

由于它仍然悬而未决（！224的观点），我想我应该给它一个去：

Since it remains unanswered (224 views!), I thought I should give it a go:

---

的问题是，在一个GridView的上下文中，将DropDownList（以下称为DDL）的动态控制，因此，其事件需要时回发到重新附加

The problem is that in the context of a GridView, the DropDownList(referred to hereafter as DDL) is a dynamic control and therefore its events need to be reattached upon Postback.

在这个概念的理解，解决方案变得相对简单：

When this concept is understood, the solution becomes relatively simple :

ASPX：

<asp:DropDownList ID="DDL1" runat="server" AutoPostBack="true" OnSelectedIndexChanged="DDL1_SelectedIndexChanged">
  <asp:ListItem Text="Review" Value="Review" Selected="True">Review</asp:ListItem>
  <asp:ListItem Text="Level1" Value="lvl1">Send Back to Level1</asp:ListItem>
</asp:DropDownList>

CS code：

CS Code:

protected void Page_Load(object sender, EventArgs e)
{
  if(!Page.IsPostBack)
  {
    // Bind the GridView to something.
    DataBindGrid();
  }
}

protected void DDL1_SelectedIndexChanged(object sender, EventArgs e)
{
  this.lblCity.Text = ((DropDownList)sender).SelectedValue;
}

protected void grdPoll_RowDataBound(object sender, GridViewRowEventArgs e)
{
  if(Page.IsPostBack)
  {
    if(e.Row.RowType == DataControlRowType.DataRow)
    {
      DropDownList ddl = e.Row.FindControl("DDL1") as DropDownList;
      if(ddl != null)
      {
        ddl.SelectedIndexChanged += new EventHandler(DDL1_SelectedIndexChanged);
      }
    }
  }
}

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