asp.net datagrid findcontrol为文本框返回null [英] asp.net datagrid findcontrol returns null for textbox

问题描述

在ASP.Net datagrid中我放置了一个下拉菜单和一个文本框（多行）。我需要在循环中读取这些值。我正在使用findControl方法获取下拉列表的引用对象，但是当我尝试使用textbox时，它返回null。

这是我的aspx代码

  ..... 
< asp：TemplateColumn> 
< HeaderTemplate> 
< asp：DropDownList 
 ID =HeaderDropDownRunat =server
 AutoPostBack =True
 OnSelectedIndexChanged =DropDown_SelectedIndexChanged/> 
< / HeaderTemplate> 
< ItemTemplate> 
< asp：DropDownList 
 ID =ItemDropDownRunat =server/> 
< / ItemTemplate> 
< / asp：TemplateColumn> 
< asp：TemplateColumn> 
< HeaderTemplate> 
详细信息
< / HeaderTemplate> 
 
< ItemTemplate> 
 
< asp：TextBox ID =txtDetailsrunat =serverTextMode =MultiLine>< / asp：TextBox> 
 
< / ItemTemplate> 
< / asp：TemplateColumn> 
 ............... 
  

C＃代码是

  for（int i = 1; i< DataGrid1.Items.Count; i ++）
 {
 DropDownList lst = DataGrid1.Items [i] .Cells [1] .FindControl（ItemDropDown）作为DropDownList; 
 String value = lst.SelectedValue; 
 String StaffId = DataGrid1.Items [i] .Cells [0] .Text; 
 TextBox txt = DataGrid1.Items [i] .Cells [2] .FindControl（txtDetaills）as TextBox; 
} 
  

我正在获得 lst 对象，但 txt 总是返回null。

解决方案

你有打字错误：

  TextBox txt = DataGrid1.Items [i] .Cells [2] .FindControl（txtDetaills）as TextBox; 
  

应该是：

 TextBox txt = DataGrid1.Items [i] .Cells [2] .FindControl（txtDetails）as TextBox; 
  

因此， txtDetaills 应为 txtDetails

in ASP.Net datagrid I placed one dropdown and a textbox (multiline). I needs to read those values in a loop. I am getting the reference object of dropdown using findControl method but when I am trying for textbox its returns null.

Here is my aspx code

.....
 <asp:TemplateColumn>
            <HeaderTemplate>
                <asp:DropDownList 
                    ID="HeaderDropDown" Runat="server" 
                    AutoPostBack="True" 
                     OnSelectedIndexChanged="DropDown_SelectedIndexChanged" />
            </HeaderTemplate>
            <ItemTemplate>
                <asp:DropDownList 
                    ID="ItemDropDown" Runat="server"/>
            </ItemTemplate>
        </asp:TemplateColumn>
          <asp:TemplateColumn >
          <HeaderTemplate>
            Details
            </HeaderTemplate>

        <ItemTemplate>

        <asp:TextBox ID="txtDetails" runat="server"  TextMode="MultiLine"></asp:TextBox>

        </ItemTemplate>       
         </asp:TemplateColumn>
...............

The C# code is

 for (int i = 1; i < DataGrid1.Items.Count; i++)
        {
            DropDownList lst = DataGrid1.Items[i].Cells[1].FindControl("ItemDropDown") as DropDownList;
            String value = lst.SelectedValue;
            String StaffId = DataGrid1.Items[i].Cells[0].Text;
            TextBox txt= DataGrid1.Items[i].Cells[2].FindControl("txtDetaills") as TextBox;
         }

I am getting the lst object correctly, but txt always returns null.

解决方案

You have a typo:

TextBox txt= DataGrid1.Items[i].Cells[2].FindControl("txtDetaills") as TextBox;

Should be:

TextBox txt= DataGrid1.Items[i].Cells[2].FindControl("txtDetails") as TextBox;

Therefore, txtDetaills should be txtDetails

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