如何获取动态创建的复选框的值

Question

我的 Webforms ASP.NET 4.5 应用程序中有一个用户表，该表由用户动态填充。在该表中，每个用户名之前都有复选框。我想删除我单击删除按钮后检查的所有用户。但是，当我单击删除按钮时，虽然调用了按钮单击事件，但不会调用选中复选框的 checkedchanged 事件。单击删除按钮时如何获取这些选中复选框的值？

using Microsoft.AspNet.Identity;
using Microsoft.AspNet.Identity.EntityFramework;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

namespace WebApplication3.Account
{
    public partial class Register : System.Web.UI.Page
    {
        private UserStore<IdentityUser> userStore;
        private UserManager<IdentityUser> userManager;
        private List<string> users = new List<string>();
        protected void Page_Load(object sender, EventArgs e)
        {
            userStore = new UserStore<IdentityUser>();
            userManager = new UserManager<IdentityUser>(userStore);
            if (!IsPostBack)
            {
                fillTable();
            } 
        }

        private void fillTable()
        {
            TableHeaderRow headerRow = new TableHeaderRow();
            TableHeaderCell hCell1 = new TableHeaderCell();
            hCell1.CssClass = "col-md-1";
            hCell1.Text = "#";
            TableHeaderCell hCell2 = new TableHeaderCell();
            hCell2.Text = "Kullanıcı Adı";
            hCell2.CssClass = "col-md-5";
            headerRow.Controls.Add(hCell1);
            headerRow.Controls.Add(hCell2);
            headerRow.Controls.Add(new TableHeaderCell() { CssClass = "col-md-3" });
            headerRow.Controls.Add(new TableHeaderCell() { CssClass = "col-md-3" });
            headerRow.TableSection = TableRowSection.TableHeader;
            tblUser.Rows.Add(headerRow);

            foreach (IdentityUser user in userManager.Users.ToList())
            {
                TableRow row = new TableRow();
                TableCell cell1 = new TableCell();
                CheckBox checkBox = new CheckBox();
                checkBox.InputAttributes.Add("value", user.Id);
                checkBox.CheckedChanged += checkBox_CheckedChanged;
                cell1.Controls.Add(checkBox);
                cell1.HorizontalAlign = HorizontalAlign.Center;
                TableCell cell2 = new TableCell();
                cell2.Text = user.UserName;
                TableCell cell3 = new TableCell();
                HyperLink link = new HyperLink();
                link.Text = "Şifreyi Değiştir";
                cell3.Controls.Add(link);
                row.Controls.Add(cell1);
                row.Controls.Add(cell2);
                row.Controls.Add(new TableCell());
                row.Controls.Add(cell3);
                tblUser.Rows.Add(row);
                row.TableSection = TableRowSection.TableBody;
            }
        }

        void checkBox_CheckedChanged(object sender, EventArgs e)
        {
            if (ViewState["userList"] != null)
            {
                users = (List<string>)ViewState["userList"];
            }
            CheckBox checkbox = (CheckBox)sender;
            if (checkbox.Checked)
            {
                if (!users.Contains(checkbox.InputAttributes["value"]))
                {
                    users.Add(checkbox.InputAttributes["value"]);
                }
            }
            else
            {
                if (users.Contains(checkbox.InputAttributes["value"]))
                {
                    users.Remove(checkbox.InputAttributes["value"]);
                }
            }

            ViewState["userList"] = users;
        }

        protected void btnDeleteUser_Click(object sender, EventArgs e)
        {
            foreach (string id in users)
            {
                IdentityUser user = userManager.FindById(id);
                userManager.Delete(user);
            }
            fillTable();
        }

    }
}

Answer 1

试试这个：

foreach(TableRow row in tblUser) 
{
    foreach(TableCell cell in row) 
    {
        foreach(Control ctrl in cell) 
        {
            if (ctrl.GetType() == CheckBox) 
            {
                /* get value here */
            }
        }
    }
}

Answer 2

从创建动态复选框列表的 foreach 循环中删除以下行：

checkBox.CheckedChanged += checkBox_CheckedChanged;

请添加下面的行而不是上面的行：

checkBox.Attributes.Add("name", "chkDel");
checkBox.Attributes.Add("onclick", "UncheckDelAll('chkDelAll','chkDel')");

在页面顶部的 javascript 下方：

function UncheckDelAll(HeaderChk, RowChk) {

        var cnt = 0; //Count of all the check boxes
        objSelected = document.getElementsByName(HeaderChk)
        obj = document.getElementsByName(RowChk)
        if (obj != null) {
            cnt = obj.length;
            for (var i = 0; i < cnt; i++) {
                if (obj[i].checked == true);
                cnt = 1;

            }
            if (cnt == 1)
                objSelected[0].checked = false;

        }
    }

这里是删除按钮点击事件逻辑：

protected void lkDelete_Click(object sender, EventArgs e)
{
string sPrimaryIds = (string)Request.Params["chkDel"];
// Write your delete query functionality over here
// Your delete query like this
// delete from [tablename] where UserId in (sPrimaryIds)
}

Answer 3

在你的 ByttonClickEvent 中

protected void btnDeleteUser_Click(object sender, EventArgs e)
{
foreach(var row in tblUser.Rows)
 {
   var tempcheckBox= row.Controls[0] as CheckBox;
   if(tempcheckBox.IsChecked)
    {
       //your code
    }
 }
}

row.Controls[0] 因为复选框被插入到第一列中 移动Page_LoadComplete方法中的dataBinding进程和 删除测试if(!IsPostBack)。

事实上，如果您调用 postBack，您首先会通过 Pre_Init、PageLoad、Your EventHandler，然后是 Page_Load Complete。

因此，如果您的绑定过程是在 Page_Load 中完成的。你会自动在你的 eventHandler 中找到你的 gridView，因为它是在 PageLoad 中初始化的。