FindControl 返回空文本对象

本文关键字：对象 文本 返回 FindControl | 更新日期: 2023-09-27 18:35:32

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Default.aspx.cs" Inherits="BindGridView._Default" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="false" OnRowEditing="OnRowEditing"
            OnRowCommand="GridView1_RowCommand" OnRowDataBound="GridView1_RowDataBound" OnRowUpdating="GridView1_RowUpdating">
            <Columns>
                <asp:TemplateField HeaderText="Name1">
                    <ItemTemplate>
                        <asp:Label ID="lblName1" runat="server" Text='<%# Eval("Name1")%>' />
                    </ItemTemplate>
                    <EditItemTemplate>
                        <asp:TextBox ID="txtUName1" runat="server" Text='<%# Eval("Name1")%>' />
                    </EditItemTemplate>
                </asp:TemplateField>
                 <asp:TemplateField HeaderText="Name2" >
                    <ItemTemplate>
                        <asp:Label ID="lblName2" runat="server" Text='<%# Eval("Name2")%>' />
                    </ItemTemplate>
                    <EditItemTemplate>
                        <asp:TextBox ID="txtUName2" runat="server" Text='<%# Eval("Name2")%>' />
                    </EditItemTemplate>
                </asp:TemplateField>
                  <asp:TemplateField HeaderText="Name3" >
                    <ItemTemplate>
                        <asp:Label ID="lblName3" runat="server" Text='<%# Eval("Name3")%>' />
                    </ItemTemplate>
                    <EditItemTemplate>
                        <asp:TextBox ID="txtUName3" runat="server" Text='<%# Eval("Name3")%>' />
                    </EditItemTemplate>
                </asp:TemplateField>
                 <asp:TemplateField HeaderText="Country">
                    <ItemTemplate>
                        <asp:Label ID="lblCountry" runat="server" Text='<%# Eval("Country")%>' />                       
                    </ItemTemplate>
                    <EditItemTemplate>
                     <asp:HiddenField ID="hdnCountry" runat="server" Value='<%#Eval("country") %>' />
                       <%-- <asp:TextBox ID="txtCountry" runat="server" Text='<%# Eval("Country")%>' />--%>
                        <asp:DropDownList ID="DrpDownList1" runat="server" >
                        <asp:ListItem>India</asp:ListItem>
                        <asp:ListItem>United States</asp:ListItem>
                        <asp:ListItem>France</asp:ListItem>
                        <asp:ListItem>Russia</asp:ListItem>
                        </asp:DropDownList>
                    </EditItemTemplate>
                </asp:TemplateField>
                 <asp:TemplateField>
                    <ItemTemplate>
                        <asp:LinkButton ID="LinkButton1" Text="Edit" runat="server" CommandName="Edit" CommandArgument='<%# DataBinder.Eval(Container.DataItem, "Id") %>' />
                    </ItemTemplate>
                    <EditItemTemplate>
                        <asp:LinkButton ID="LinkButton2" Text="Update" runat="server" CommandName="Update"/>
                        <asp:LinkButton ID="LinkButton3" Text="Cancel" runat="server" OnClick="OnCancel" />
                    </EditItemTemplate>
                </asp:TemplateField>               
            </Columns>
        </asp:GridView>
    </div>
    </form>
</body>
</html>

前端

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data;
namespace BindGridView
{
    public partial class _Default : System.Web.UI.Page
    {
        public List<Employee> lstEmp = new List<Employee>();
        protected void Page_Load(object sender, EventArgs e)
        {
            if (!this.IsPostBack)
            {
                BindGrid();
            }
        }
        protected void BindGrid()
        {
            List<Employee> lstEmp = ReturnList();
            GridView1.DataSource = lstEmp;
            GridView1.DataBind();
        }
        protected void OnRowEditing(object sender, GridViewEditEventArgs e)
        {        
            GridView1.EditIndex = 0;
            BindEdit(Session["Name"].ToString());
        }
        protected void OnCancel(object sender, EventArgs e)
        {
            GridView1.EditIndex = -1;
            this.BindGrid();
        }
        private void BindEdit(string id)
        {
            List<Employee> lstEmp = ReturnList();
            lstEmp = new List<Employee>(lstEmp.Where(x => x.Id.ToString() == id).ToList());
            GridView1.DataSource = lstEmp;
            GridView1.DataBind();
        }
        protected void GridView1_RowCommand(object sender, GridViewCommandEventArgs e)
        { 
            try
            {
                if (e.CommandName == "Edit")//redirect to MangeRulepage and set query string Mode variable to 'EDIT'
                {
                    //BindEdit(e.CommandArgument.ToString());
                    Session["Name"] = e.CommandArgument.ToString();
                }
            }
            catch (Exception ex)
            {
                throw ex;
            }     
        }
        protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)
        {
            if (e.Row.RowType == DataControlRowType.DataRow && GridView1.EditIndex == e.Row.RowIndex)
            {
                DropDownList ddl = (DropDownList)e.Row.FindControl("DrpDownList1");
                HiddenField hdnval = (HiddenField)e.Row.FindControl("hdnCountry");
                if (ddl != null)
                { 
                    ddl.Items.FindByValue(hdnval.Value).Selected = true;
                }
            }
        }
        protected void GridView1_RowUpdating(object sender, GridViewUpdateEventArgs e)
        {
            //GridView1.EditIndex = -1;           
            TextBox tb = (TextBox)GridView1.FindControl("txtUName1");// Not getting object *tb* in case of update
            if (tb != null)
            {
                string text = tb.Text;
            }          
        }
        public class Employee
        {
          public int Id { get; set; }
          public string Name1 { get; set; }
          public string Name2 { get; set; }
          public string Name3 { get; set; }
          public string Country { get; set; }            
        }
        private List<Employee> ReturnList()
        {
            DataTable dt = new DataTable();
            dt.Columns.AddRange(new DataColumn[3] { new DataColumn("Id"), new DataColumn("Name"), new DataColumn("Country") });
            dt.Rows.Add(1, "1,2,3", "United States");
            dt.Rows.Add(2, "", "India");
            dt.Rows.Add(3, "4,5,6", "France");
            dt.Rows.Add(4, "", "Russia");
            for (int i = 0; i < dt.Rows.Count; i++)
            {
                Employee emp = new Employee();
                emp.Id = Convert.ToInt32(dt.Rows[i]["Id"]);
                emp.Name1 = dt.Rows[i]["Name"].ToString();
                emp.Country = dt.Rows[i]["Country"].ToString();
                lstEmp.Add(emp);
            }
            return lstEmp;
        }
    }

}

长时间后 ASP.Net GridView，我无法在EditItemTemplate的GridView中找到文本框对象。从过去几个小时开始谷歌搜索，但无法找到我的问题的解决方案。

请帮忙。

FindControl 返回空文本对象

尝试使用以下代码查找文本框

 GridViewRow row = TaskGridView.Rows[e.RowIndex];
TextBox tb = (TextBox)(row.Cells[0].Controls[0]);

或

  TextBox tb = (TextBox)(row.FindControl("txtUName1"));

希望这对你有帮助

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