c# - 在 itemTemplate 中查找标签并从后面的代码绑定(bind)数据

Question

我想在标签中显示值(标签在 itemTemplate 中)

我试过这种方法

string s = null;
SelfCollectNameSpace.SelfCollect address = new SelfCollectNameSpace.SelfCollect();

s = address.getSelfCollectAddress(orderNoTracking);

    if (string.IsNullOrEmpty(s) == false)
    {
        foreach (GridViewRow row in GridView1.Rows)
        {
            string LabelText = ((Label)row.FindControl("labelSelf")).Text;
            LabelText = s;
            Response.Write(LabelText+"test");
        }
     }

但gridview 内的标签中没有显示任何内容。 IT 应该显示 s 的值。

下一个方法是

    string s = null;
    SelfCollectNameSpace.SelfCollect address = new SelfCollectNameSpace.SelfCollect();
    s = address.getSelfCollectAddress(orderNoTracking);

       Label labelSelfCollect = GridView1.FindControl("labelSelf") as Label;
       labelSelfCollect.Text = "Self Collect at "+ s;  

我遇到了这个错误

    System.NullReferenceException: Object reference not set to an instance of an object.

我使用的最后一种方法是

    string s = null;
    SelfCollectNameSpace.SelfCollect address = new SelfCollectNameSpace.SelfCollect();
    s = address.getSelfCollectAddress(orderNoTracking);
    if (string.IsNullOrEmpty(s) == false)
    {
        foreach (GridViewRow row in GridView1.Rows)
        {
            if (row.RowType == DataControlRowType.DataRow)
            {
                Label labelcollect = row.FindControl("labelSelf") as Label;
                labelcollect.Text = "self collect at "+ s;
            }             
        }           

    }

使用此方法也没有显示任何内容。我应该如何将 s 值分配给此 labelSelf(itemTemplate 内的标签)？

我的aspx代码

              <asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False" Width="772px" style="margin-left: 120px; text-align: left"  Height="100px"  DataKeyNames ="progressID" OnRowDataBound="GridView1_OnRowDataBound" OnRowDeleting="GridView1_RowDeleting" CellPadding="4" CssClass="rounded_corners" HeaderStyle-Height="40px">
                    <AlternatingRowStyle CssClass="rounded_corners tr tr" />                        
                     <Columns>
                        <asp:BoundField ControlStyle-BorderWidth="60" DataField="dateupdate" HeaderText="Date Update" DataFormatString="{0:dd/MM/yyyy}" >
                        <ControlStyle BorderWidth="60px" />
                        </asp:BoundField>
                        <asp:TemplateField HeaderText="Progress">
                           <ItemTemplate >                          
                                    <%# Eval("message") %> 
                               <br />
                          <asp:label ID="labelRemark" runat="server" style="Font-Size:11.5px;" text='<%# Eval("remark") %>'></asp:label><br />
                               <asp:Label ID="labelSelf" runat="server" style="Font-Size:11.5px;" ></asp:Label><br />
                               <div id="div<%# Eval("progressID") %>"  >                       
                                                  <asp:GridView ID="GridView2" runat="server" AutoGenerateColumns="False"
                                                        DataKeyNames="progressID"  style="text-align:center; font-size:small;" CellPadding="4" OnRowCommand="GridView2_RowCommand" GridLines="None" CssClass="rounded_corners" Width="500px" >
                                                        <AlternatingRowStyle BackColor="White" />
                                                        <Columns>
                                                            <asp:BoundField DataField="tackingNo" HeaderText="Courier Tracking No"  ItemStyle-Font-Size="Small" ItemStyle-Width="150px" >
                                                            </asp:BoundField>
                                                            <asp:BoundField DataField="courierDate" HeaderText="Courier Date">
                                                            </asp:BoundField>
                           <asp:TemplateField HeaderText="Provider">
                             <ItemTemplate>
                                      <asp:HyperLink Text='<%#Eval("providernm")%>' Target="_blank" runat="server" DataNavigateUrlFields="companyurl" NavigateUrl='<%#Eval("companyurl")%>' ></asp:HyperLink>
                                   <br />
                                   </ItemTemplate>
                        </asp:TemplateField>   
                    <asp:TemplateField HeaderText="Tracking" >
                                  <ItemTemplate>
                                      <br />
                                      <asp:HyperLink Text="Track Here" Target="_blank" runat="server" DataNavigateUrlFields="trackingurl" NavigateUrl='<%#Eval("trackingurl")%>' ></asp:HyperLink>
                                     <br />
                                     <asp:Label ID="Label4" runat="server" Text="* check after 24 hours" Font-Italic="true"></asp:Label>
                                   </ItemTemplate>
                        </asp:TemplateField>

                                                        </Columns>
                                                    </asp:GridView>
                                             </div>

                        </ItemTemplate>                                                        
                        </asp:TemplateField>

                       <asp:TemplateField ShowHeader="false">
                             <ItemTemplate>
                                 <asp:LinkButton ID="LinkButtonDELETE" runat="server" CommandName="Delete" Text="Delete" OnClientClick= "return confirm('Confirm Delete progress?')"></asp:LinkButton>
                             </ItemTemplate>
                         </asp:TemplateField>

                   </Columns>

谢谢。

Answer 1

使用 GridView1_OnRowDataBound 而不是 foreach(GridView1.Rows 中的 GridViewRow 行)。除此之外，您的第一种方法是正确的。您根本没有在那里分配 Text 属性，而是从中读取。

SelfCollectNameSpace.SelfCollect address = new SelfCollectNameSpace.SelfCollect();

protected void MyGrid_RowDataBound(object sender, GridViewRowEventArgs e)
{
  if(e.Row.RowType == DataControlRowType.DataRow)
  {
      Label labelSelf = (Label)e.Row.FindControl("labelSelf");
      labelSelf.Text = address.getSelfCollectAddress(orderNoTracking); // maybe you need to retrieve the orderNoTracking from another control in this row or from it's datasource
  }
}