[英]Dropdownlist not updating in UpdatePanel
我创建了一个简单的页面,其中在UpdatePanel中有两个下拉列表。 当第一个Dropdownlist更改选择时,应该更新第二个dropdownlist的列表,但是它不起作用,并且我不确定自己在做什么错。
我收到以下错误:在UpdatePanel“ HeadUpdatePanel”中找不到触发器的ID为“ ctl00 $ MainContent $ FunctionCombo”的控件。
即使如此,当我单步执行时也会找到它并且它不为null。 看到这一行:
DropDownList dd = (DropDownList)cph.FindControl("FunktionCombo");
但是,当它尝试应用触发器时,就会出现以下错误:
trigger.ControlID = cph.FindControl("FunktionCombo").UniqueID;
仅供参考:母版页没有任何内容,仅调用TestPage!
这是我的TestPage代码:
<%@ Page Title="" Language="C#" MasterPageFile="~/Main.Master" AutoEventWireup="true" CodeBehind="TestPage.aspx.cs" Inherits="Test.TestPage" %>
<asp:Content ID="BodyContent" ContentPlaceHolderID="MainContent" runat="server">
<asp:ScriptManager ID="ScriptManager" runat="server" />
<div class="container">
<div>
<asp:UpdatePanel ID="HeadUpdatePanel" UpdateMode="Always" runat="server">
<ContentTemplate>
<asp:Label ID="Label1" runat="server" Text="Wähle Funktion:" />
<asp:DropDownList ID="FunktionCombo" OnSelectedIndexChanged="FunktionCombo_SelectionChanged" AutoPostBack="true" runat="server" />
<asp:Label ID="Label2" runat="server" Text="Wähle Tabelle:" />
<asp:DropDownList ID="TabelleCombo" OnSelectedIndexChanged="TabelleCombo_SelectionChanged" AutoPostBack="true" runat="server" />
<asp:Label ID="CountLbl" runat="server" Text="Wähle Funktion:" />
<asp:Button ID="StartBn" runat="server" Text="Start" onclick="StartBtn_Click" />
</ContentTemplate>
</asp:UpdatePanel>
</div>
</div>
</asp:Content>
using System;
using System.Collections.Generic;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
namespace Test
{
public partial class TestPage : System.Web.UI.Page
{
private List<ViewInfo> _ospList;
private List<ViewInfo> _aeList;
private List<ViewInfo> _icList;
private bool _functionChanged = false;
private string _currentFunctionDisplay = "";
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
HttpContext.Current.Session["IsAdmin"] = true;
HttpContext.Current.Session["IsSubAdmin"] = true;
CreateComboLists();
ContentPlaceHolder cph = (ContentPlaceHolder)this.Master.FindControl("MainContent");
UpdatePanelControlTrigger trigger = new PostBackTrigger();
DropDownList dd = (DropDownList)cph.FindControl("FunktionCombo");
trigger.ControlID = cph.FindControl("FunktionCombo").UniqueID;
HeadUpdatePanel.Triggers.Add(trigger);
}
}
private void CreateComboLists()
{
if ((bool)HttpContext.Current.Session["IsAdmin"] == true)
{
FunktionCombo.Items.Add("OSP");
FunktionCombo.Items.Add("AE");
FunktionCombo.Items.Add("IC");
FunktionCombo.DataBind();
FunktionCombo.SelectedIndex = 0;
_ospList = GetSprocList("OSP", (HttpContext.Current.Session["IsAdmin"] != null) ? (bool)HttpContext.Current.Session["IsAdmin"] : false, (HttpContext.Current.Session["IsSubAdmin"] != null) ? (bool)HttpContext.Current.Session["IsSubAdmin"] : false);
_aeList = GetSprocList("AE", (HttpContext.Current.Session["IsAdmin"] != null) ? (bool)HttpContext.Current.Session["IsAdmin"] : false, (HttpContext.Current.Session["IsSubAdmin"] != null) ? (bool)HttpContext.Current.Session["IsSubAdmin"] : false);
_icList = GetSprocList("IC", (HttpContext.Current.Session["IsAdmin"] != null) ? (bool)HttpContext.Current.Session["IsAdmin"] : false, (HttpContext.Current.Session["IsSubAdmin"] != null) ? (bool)HttpContext.Current.Session["IsSubAdmin"] : false);
TabelleCombo.DataSource = _ospList;
TabelleCombo.DataTextField = "ViewName";
TabelleCombo.DataValueField = "SprocName";
TabelleCombo.SelectedIndex = 0;
TabelleCombo.DataBind();
}
}
protected void FunktionCombo_SelectionChanged(object sender, System.EventArgs e)
{
DropDownList obj = (DropDownList)sender;
TabelleCombo.DataSource = null;
_functionChanged = true;
if (FunktionCombo.SelectedValue.ToString() == "OSP")
{
TabelleCombo.DataSource = _ospList;
TabelleCombo.DataTextField = "ViewName";
TabelleCombo.DataValueField = "SprocName";
_currentFunctionDisplay = "OSP";
}
else if (FunktionCombo.SelectedValue.ToString() == "AE")
{
TabelleCombo.DataSource = _aeList;
TabelleCombo.DataTextField = "ViewName";
TabelleCombo.DataValueField = "SprocName";
_currentFunctionDisplay = "AE";
}
else if (FunktionCombo.SelectedValue.ToString() == "IC")
{
TabelleCombo.DataSource = _icList;
TabelleCombo.DataTextField = "ViewName";
TabelleCombo.DataValueField = "SprocName";
_currentFunctionDisplay = "IC";
}
TabelleCombo.DataBind();
TabelleCombo.SelectedIndex = 0;
SetCountText();
}
protected void TabelleCombo_SelectionChanged(object sender, System.EventArgs e)
{
DropDownList obj = (DropDownList)sender;
}
private void SetCountText(string text = "")
{
CountLbl.Text = TabelleCombo.SelectedValue.ToString();
}
public static List<ViewInfo> GetSprocList(string function, bool isAdmin, bool isSubAdmin, bool infoPanel = false)
{
List<ViewInfo> sl = new List<ViewInfo>();
switch (function)
{
case "OSP":
sl.Add(new ViewInfo("First Meetings Set", "sp_Activity_OSP_First"));
sl.Add(new ViewInfo("Contacts", "sp_Activity_OSP_Contact"));
return sl;
case "AE":
sl.Add(new ViewInfo("Dials", "sp_Activity_AE_Dials"));
sl.Add(new ViewInfo("Dials Daily", "sp_Activity_AE_Dials_Daily"));
return sl;
case "IC":
sl.Add(new ViewInfo("Monthly Activity Callstatus", "sp_Activity_IC_CallStatus"));
return sl;
default:
sl.Add(new ViewInfo("First Meetings Set", "sp_Activity_OSP_First"));
sl.Add(new ViewInfo("Contacts", "sp_Activity_OSP_Contact"));
return sl;
}
}
}
public class ViewInfo
{
public string ViewName { get; set; }
public string SprocName { get; set; }
public string ExtraName { get; set; }
public List<ViewInfo> ViewList { get; set; }
public ViewInfo()
{
this.ViewName = "";
this.SprocName = "";
}
public ViewInfo(string name, string sproc, string extraName = "")
{
this.ViewName = name;
this.SprocName = sproc;
this.ExtraName = extraName;
}
}
}
我对此表示感谢。
好的,我找到了问题,很抱歉,因为它是如此愚蠢。 第一个问题:我删除了不需要的触发器,因为触发它的DDL位于Updatepanel内部,从而解决了该问题。
第二个问题:当我将数据源应用于FunktionCombo_SelectionChanged内部的DDL时,该列表为空,因为我忘记了它将通过回发删除。
所以我只是在运行时创建列表,现在它可以工作了。
_ospList = SprocEvaluator.GetSprocList("OSP", (HttpContext.Current.Session["IsAdmin"] != null) ? (bool)HttpContext.Current.Session["IsAdmin"] : false, (HttpContext.Current.Session["IsSubAdmin"] != null) ? (bool)HttpContext.Current.Session["IsSubAdmin"] : false);
TabelleCombo.DataSource = _ospList;
再次,对此表示抱歉,但感谢您的所有帮助!
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