gridview的行编辑 - 动态绑定到一个DropDownList [英] Gridview row editing - dynamic binding to a DropDownList

问题描述

我试图得到一个ASP.NET 3.5 GridView控件显示一个选择的值作为字符串显示时，表现出一个DropDownList，让我从选项列表给出挑值正在编辑的时候。似乎很简单？

I'm trying to get an ASP.NET 3.5 GridView to show a selected value as string when being displayed, and to show a DropDownList to allow me to pick a value from a given list of options when being edited. Seems simple enough?

我的GridView控件看起来像这样（简体）：

My gridview looks like this (simplified):

<asp:GridView ID="grvSecondaryLocations" runat="server" 
              DataKeyNames="ID" OnInit="grvSecondaryLocations_Init" 
              OnRowCommand="grvSecondaryLocations_RowCommand" 
              OnRowCancelingEdit="grvSecondaryLocations_RowCancelingEdit"
              OnRowDeleting="grvSecondaryLocations_RowDeleting"
              OnRowEditing="grvSecondaryLocations_RowEditing" 
              OnRowUpdating="grvSecondaryLocations_RowUpdating"  >
<Columns>
    <asp:TemplateField>
         <ItemTemplate>
              <asp:Label ID="lblPbxTypeCaption" runat="server" 
                                 Text='<%# Eval("PBXTypeCaptionValue") %>' />
         </ItemTemplate>
         <EditItemTemplate>
                      <asp:DropDownList ID="ddlPBXTypeNS" runat="server" 
                               Width="200px" 
                               DataTextField="CaptionValue" 
                               DataValueField="OID" />
         </EditItemTemplate>
    </asp:TemplateField>
</asp:GridView>

当不在编辑模式网格获取显示确定 - 选定的PBX类型显示了其在asp值：Label控件。这并不奇怪。

The grid gets displayed OK when not in editing mode - the selected PBX type shows its value in the asp:Label control. No surprise there.

我的DropDownList的值列表加载到一个名为 _pbxTypes 中的的的OnLoad 事件本地成员形成。我证实了这一 - 它的工作原理，值有

I load the list of values for the DropDownList into a local member called _pbxTypes in the OnLoad event of the form. I verified this - it works, the values are there.

现在我的挑战是：当电网进入编辑模式特定行，我需要绑定存储在 _pbxTypes PBX的列表。

Now my challenge is: when the grid goes into editing mode for a particular row, I need to bind the list of PBX's stored in _pbxTypes.

够简单了，我想 - 刚刚抢下拉在 RowEditing 事件列表对象并附名单：

Simple enough, I thought - just grab the drop down list object in the RowEditing event and attach the list:

protected void grvSecondaryLocations_RowEditing(object sender, GridViewEditEventArgs e)
{
    grvSecondaryLocations.EditIndex = e.NewEditIndex;

    GridViewRow editingRow = grvSecondaryLocations.Rows[e.NewEditIndex];

    DropDownList ddlPbx = (editingRow.FindControl("ddlPBXTypeNS") as DropDownList);
    if (ddlPbx != null)
    {
        ddlPbx.DataSource = _pbxTypes;
        ddlPbx.DataBind();
    }

    .... (more stuff)
}

麻烦的是 - 我从来没有从的FindControl 呼叫得到任何东西 - 好像 ddlPBXTypeNS 不存在（或不能被找到）。

Trouble is - I never get anything back from the FindControl call - seems like the ddlPBXTypeNS doesn't exist (or can't be found).

我在想什么？必须有一些非常愚蠢的....但到目前为止，我所有的谷歌搜索，阅读了有关的GridView控件，并要求哥们没有帮助。

What am I missing?? Must be something really stupid.... but so far, all my Googling, reading up on GridView controls, and asking buddies hasn't helped.

谁能发现缺少的环节？ ; - ）

Who can spot the missing link? ;-)

推荐答案

很容易...你就错了，因为该事件的控制是不存在的：

Quite easy... You're doing it wrong, because by that event the control is not there:

protected void gv_RowDataBound(object sender, GridViewRowEventArgs e)
{
    if (e.Row.RowType == DataControlRowType.DataRow && 
        (e.Row.RowState & DataControlRowState.Edit) == DataControlRowState.Edit)
    { 
        // Here you will get the Control you need like:
        DropDownList dl = (DropDownList)e.Row.FindControl("ddlPBXTypeNS");
    }
}

也就是说，它只会有效期为的DataRow （实际数据行），如果它在修改模式..因为你只有一次编辑一行。在 e.Row.FindControl（ddlPBXTypeNS）只能找到您想要的控制。

That is, it will only be valid for a DataRow (the actually row with data), and if it's in Edit mode... because you only edit one row at a time. The e.Row.FindControl("ddlPBXTypeNS") will only find the control that you want.

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