コントロールのリストを再作成するときに重複するパネル/リストID

Question

[削除]ボタンをクリックすると、パネルを削除し、残りのパネルを繰り返し、最初から新しいIDを付けます。私が6パネルのリストからPanel（3）を削除した場合、私はそれを反復して、すべての新しいIDパネル0〜5を与えます。

私の問題は、ID名が重複しているパネルを削除した後でもエラーが発生し続けることです。私の人生にとって私はどこに間違っているのか分からないので、私は目が見えなくなったり助言を求めていることを期待しています。

btnDelete関数でブレークポイントを設定していましたが、同じIDの複数のパネルで問題が発生する理由が論理的にはわかりません。

ASPX：背後

<%@ Page Title="" Language="C#" MasterPageFile="~/MasterPage/MasterPage.master" AutoEventWireup="true" CodeFile="Search.aspx.cs" Inherits="Search" EnableTheming="true" %> 

<asp:Content ID="Content1" ContentPlaceHolderID="head" runat="Server"> 
<link href="App_Themes/ui-lightness/jquery-ui-1.7.2.custom.css" rel="stylesheet" 
    type="text/css" /> 
<link href="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8/themes/base/jquery-ui.css" 
    rel="stylesheet" type="text/css" /> 
<script src="Includes/JavaScript/jquery-1.7.1.js" type="text/javascript"></script> 
<script src="Includes/JavaScript/jquery.ui.datepicker.js" type="text/javascript"></script> 
<script src="Includes/JavaScript/jquery.ui.widget.js" type="text/javascript"></script> 
<script src="Includes/JavaScript/jquery.ui.core.js" type="text/javascript"></script> 
<%--Script for the Dropdown Datepicker--%> 
<script type="text/javascript"> 
    $(function() { 
     $("input.datepicker").datepicker({ showOn: 'button', buttonImage: 'Includes/Images/calender.gif', buttonImageOnly: false, onSelect: function() { } 
     }); 
    }); 
</script> 
</asp:Content> 
<asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder2" runat="Server"> 
<h1> 
    Search 
    <asp:HyperLink ID="HyperLink1" runat="server" ImageUrl="Includes/Images/action_help.gif" 
     NavigateUrl="~/user_manual.pdf" Target="_blank" ToolTip="Search Help"></asp:HyperLink></h1> 
<table border="0" cellpadding="6" cellspacing="0"> 
<tr> 
<td> 
    <asp:Button ID="btnAdd" runat="server" Text="Add Control" onclick="btnAdd_Click" /> 
    <asp:Button ID="btnClear" runat="server" Text="Reset" onclick="btnClear_Click" /> 
    <asp:Button ID="btnSearch" runat="server" Text="Search" OnClick="btnSearch_Click" /> 

</td> 
<td> 
    <asp:TextBox ID="txtTitle" class="searchPage" runat="server"></asp:TextBox> 
</td> 
</tr> 
<tr> 
<td> 
<asp:PlaceHolder ID="myPlaceholder" runat="server"></asp:PlaceHolder> 
</td> 

コード：

using System; 
using System.Collections.Generic; 
using System.Web; 
using System.Web.UI; 
using System.Web.UI.WebControls; 
using System.Runtime.Serialization; 
using System.Configuration; 
using System.Data; 
using System.Data.SqlClient; 

public partial class Search : BasePage 
{ 
    List<Users> userroles = new List<Users>(); 
    //Panel that contains all our Dynamically added user controls. 
    List<Panel> persistControls = new List<Panel>(); 

    public int userid = 0; 
    public byte IsActive = 1; 
    public int error = 0; 

protected override void OnInit(EventArgs e) 
{ 
    base.OnInit(e); 
} 

// Calls three functions responsible for pulling from the Database and binding the Datagrid. 
protected void Page_Load(object sender, EventArgs e) 
{ 
    if (!IsPostBack) 
    { 
     GetClustersFromDB(userid); 
     BindGrid(); 
     BindState();   
    } 
    else 
    { 
     // Where I am recreating my controls. 
     DynamicQueryRecreateLogic(); 
    } 
} 

protected void DynamicQueryRecreateLogic() 
{ 
    if (Session["persistControls"] != null) 
    { 
     // Local Value that contains the members of the current persistControls session, not yet pushed to the page. 
     persistControls = (List<Panel>)Session["persistControls"]; 
     int count = 0; 

     foreach (Panel panel in persistControls) 
     { 
      //AddQuestionTypeDropDownList(count); 
      panel.ID = "panel" + "(" + count.ToString() + ")"; 

      foreach (Control control in panel.Controls) 
      { 
       if (control.GetType() == typeof(DropDownList)) 
       { 
        control.ID = "list" + "(" + count.ToString() + ")"; 
        DropDownList list = (DropDownList)panel.FindControl(control.ID); 
        list.SelectedIndexChanged += new EventHandler(list_SelectedIndexChanged); 
       } 
       if (control.GetType() == typeof(TextBox)) 
       { 
        control.ID = "txtBox" + "(" + count.ToString() + ")"; 
       } 
      } 

      // Re-Adding our Remove Button 
      Button btnRemove = new Button(); 
      btnRemove.Click += new EventHandler(btnDelete_Click); 
      btnRemove.Text = "Remove"; 
      btnRemove.CommandArgument = count.ToString(); 

      // Pushing to Placeholder 
      myPlaceholder.Controls.Add(panel); 
      myPlaceholder.Controls.Add(btnRemove); 
      count++; 
     } 
    } 
} 

private DropDownList AddQuestionTypeDropDownList() 
{ 
    DropDownList list = new DropDownList(); 

    list.ID = "list" + "(" + persistControls.Count.ToString() + ")"; 
    list.Items.Add(new ListItem("--Select One--", "")); 
    list.Items.Add(new ListItem("Title", "1")); 
    list.Items.Add(new ListItem("Contact", "2")); 
    list.Items.Add(new ListItem("Date Created", "3")); 
    list.SelectedIndexChanged += new EventHandler(list_SelectedIndexChanged); 
    list.AutoPostBack = true; 

    return list; 
} 

private TextBox AddFieldTypeTextBox(int count) 
{ 
    TextBox box = new TextBox(); 
    box.ID = "txtBox" + "(" + count.ToString() + ")"; 
    return box; 
} 

protected void btnAdd_Click(object sender, EventArgs e) 
{ 
    try 
    { 
     Panel panelContainer = new Panel(); 
     panelContainer.ID = "panel" + "(" + persistControls.Count.ToString() + ")"; 

     panelContainer.Controls.Add(AddQuestionTypeDropDownList()); 

     Button btnRemove = new Button(); 
     btnRemove.Click += new EventHandler(btnDelete_Click); 
     btnRemove.Text = "Remove"; 
     btnRemove.CommandArgument = persistControls.Count.ToString(); 

     persistControls.Add(panelContainer); 

     myPlaceholder.Controls.Add(panelContainer); // Pushes the Panel to the page. 
     myPlaceholder.Controls.Add(btnRemove); // Pushes our Button to the page. 

     Session["persistControls"] = persistControls; // put it in the session 
    } 
    catch 
    { 
     throw; 
    } 
} 

protected static string DecipherCountNumber(string IDHolder) 
{ 
    int start = IDHolder.IndexOf("("); 

    if (start == -1) 
    { 
     return IDHolder; 
    } 
    else 
    { 
     return IDHolder.Substring(start + 1).Replace(")", string.Empty); 
    } 
} 

protected void list_SelectedIndexChanged(object sender, EventArgs e) 
{ 
    //I need to fix the dynamic Add location. I need to track some type of enumeration or attributes of the panel for recreation. 
    try 
    { 
     DropDownList list = (DropDownList)sender; 
     string IDHolder = list.ID.ToString(); 
     int count = Convert.ToInt32(DecipherCountNumber(IDHolder)); 
     Panel panelContainer = persistControls.Find(delegate(Panel panel) { return panel.ID == "panel" + "(" + count.ToString() + ")"; }); 

     if (list.SelectedIndex == 1) 
     { 
      //panelContainer.Controls.Add(AddFieldTypeTextBox(count)); 
     } 
     if (list.SelectedIndex == 2) 
     { 
      //panelContainer.Controls.Remove(FindControl("txtBox" + "(" + count.ToString() + ")")); 
     } 
     if (list.SelectedIndex == 3) 
     { 
      //panelContainer.Controls.Remove(FindControl("txtBox" + "(" + count.ToString() + ")")); 
     } 

     Session["persistControls"] = persistControls; 
    } 
    catch 
    { 
     throw; 
    } 
} 

protected void btnClear_Click(object sender, EventArgs e) 
{ 
    try 
    { 
     Session["persistControls"] = null; 
     Response.Redirect(Request.Url.ToString()); 
    } 
    catch 
    { 
     throw; 
    } 
} 

protected void btnDelete_Click(object sender, EventArgs e) 
{ 
    try 
    { 
     int deleteThisOne = int.Parse(((Button)sender).CommandArgument); 
     persistControls.Remove(persistControls[deleteThisOne]); 

     Session["persistControls"] = persistControls; 

     Response.Redirect(Request.Url.ToString(), false); 
    } 
    catch 
    { 
     throw; 
    } 
} 

Answer 1

私はむしろPageLoadよりもレクリエーションのOnInit行うには、私のDynamicQueryControlsを修正。これをPageLoadレベルで作成すると、かなりの問題が発生します。