I was trying this from some time, but I am not able to get around it. Following is the code of the aspx page display:
<!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">
Test<br />
<asp:DropDownList ID="DropDownList1" runat="server">
<asp:ListItem>1</asp:ListItem>
<asp:ListItem>2</asp:ListItem>
</asp:DropDownList>
<asp:ScriptManager ID="ScriptManager1" runat="server">
</asp:ScriptManager>
<asp:UpdatePanel ID="UpdatePanel1" runat="server" UpdateMode="Conditional">
<ContentTemplate>
<br />
<asp:Label ID="Label1" runat="server" Text="Label"></asp:Label>
</ContentTemplate>
</asp:UpdatePanel>
</form>
</body>
</html>
Following is the code for the button1 click event:
Public Class WebForm1
Inherits System.Web.UI.Page
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
End Sub
Protected Sub DropDownList1_SelectedIndexChanged(ByVal sender As Object, ByVal e As EventArgs) Handles DropDownList1.SelectedIndexChanged
Label1.Text = DropDownList1.SelectedIndex
UpdatePanel1.Update()
End Sub
End Class
Could you please tell me what I missed out.
Set the autopostback to true in the drop down.
The true means: everytime the value in the drop down changes, a postback to the server will occur.
But listen to Tim Schmelter answer. If the drop down will not change, it's a good idea to put it outside the update panel and the update panel must be triggered asynchronous by the drop down (if you don't set a trigger to the update panel, every postback will update your updatepanel). If the content of the dropdown changes, put it inside the updatepanel.
But like I said, I'm not using that for a long time, its a good idea to double check everything I say about the subject. =p
PS: Microsoft Update Panels are easy to develop but make your site very slow. Try to learn about aspnet webservices and jQuery.
You have forgotten to set AutoPostback to True on your DropDownList. The default is False.
http://msdn.microsoft.com/en-us/library/system.web.ui.webcontrols.listcontrol.autopostback.aspx
And if you want to trigger Async-Postback in your UpdatePanel if the User changes the DropDownList, you have to specify an AsyncPostbackTrigger for the UpdatePanel, because the DropDown is outside of it.
<Triggers>
<asp:AsyncPostBackTrigger ControlID="DropDownList1" EventName="SelectedIndexChanged" />
</Triggers>
Apart from that you need to place the ScriptManager at the beginning as Ed said.
Look here for more infos on ASP.NET-Ajax:
http://msdn.microsoft.com/en-us/magazine/cc163354.aspx
You need to place your Scriptmanager before any controls that will use it.
So place it above your dropdownlist control.
You also need to set the AutoPostBack property to true on the dropdownlist for the selectedindexchange event to fire on it.
<body>
<form id="form1" runat="server">
<asp:ScriptManager ID="ScriptManager1" runat="server" />
Test<br />
<asp:DropDownList ID="DropDownList1" runat="server" AutoPostback="true">
<asp:ListItem>1</asp:ListItem>
<asp:ListItem>2</asp:ListItem>
</asp:DropDownList>
<asp:UpdatePanel ID="UpdatePanel1" runat="server" UpdateMode="Conditional">
<ContentTemplate>
<br />
<asp:Label ID="Label1" runat="server" Text="Label"></asp:Label>
</ContentTemplate>
</asp:UpdatePanel>
</form>
</body>
Below is the correct markup, just put it to your page:
<!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">
Test<br />
<asp:DropDownList ID="DropDownList1" runat="server" AutoPostback ="True">
<asp:ListItem>1</asp:ListItem>
<asp:ListItem>2</asp:ListItem>
</asp:DropDownList>
<asp:ScriptManager ID="ScriptManager1" runat="server">
<Triggers>
<asp:AsyncPostBackTrigger ControlID="DropDownList1"
EventName="SelectedIndexChanged" />
</Triggers>
</asp:ScriptManager>
<asp:UpdatePanel ID="UpdatePanel1" runat="server" UpdateMode="Conditional">
<ContentTemplate>
<br />
<asp:Label ID="Label1" runat="server" Text="Label"></asp:Label>
</ContentTemplate>
</asp:UpdatePanel>
</form>
Related
I am working on a web application (IIS) targeting .NET 4.0 using Visual Studio 2015.
I have an .aspx that contains 4 usercontrols (.ascx). When one of the usercontrols posts back the main .aspx AND the other three usercontrols also do a postback.
I'm looking for a way to prevent the other usercontrols from doing a postback when one of them does.
I've tried putting each of the usercontrols within an updatepanel (code below). I've tried putting an updatepanel within each usercontrol. I've tried changing the ChildrenAsTriggers and UpdateMode properties. I've tried creating a Click event in each usercontrol that's raised when the items within the usercontrol post back (example on just one of the usercontrols below).
No matter what, the page and all four usercontrols all do a postback every time one of them does.
Main .ASPX:
<%# Register Assembly="AjaxControlToolkit" Namespace="AjaxControlToolkit" TagPrefix="cc1" %>
<%# Register TagPrefix="uc1" TagName="Components" Src="Components.ascx" %>
<%# Register TagPrefix="uc2" TagName="Options" Src="Options.ascx" %>
<%# Register TagPrefix="uc3" TagName="Settings" Src="Settings.ascx" %>
<%# Register TagPrefix="uc4" TagName="Menu" Src="Menu.ascx" %>
<form id="form1" runat="server">
<cc1:ToolkitScriptManager ID="ToolkitScriptManager1" runat="server" EnablePartialRendering="true"></cc1:ToolkitScriptManager>
<asp:Panel ID="pnlComponents" runat="server">
<asp:UpdatePanel ID="updpnlComponents" runat="server">
<ContentTemplate>
<uc1:Components id="Components" runat="server"></uc1:Components>
</ContentTemplate>
</asp:UpdatePanel>
</asp:Panel>
<asp:Panel ID="pnlOptions" runat="server">
<asp:UpdatePanel ID="updpnlOptions" runat="server">
<ContentTemplate>
<uc2:Options id="Options" runat="server" CssClass="jQTrackChanges"></uc2:Options>
</ContentTemplate>
</asp:UpdatePanel>
</asp:Panel>
<asp:Panel ID="pnlSettings" runat="server">
<asp:UpdatePanel ID="updpnlSettings" runat="server">
<Triggers>
<asp:AsyncPostBackTrigger ControlID="Settings" EventName="Click" />
</Triggers>
<ContentTemplate>
<uc3:Settings id="Settings" runat="server" CssClass="jQTrackChanges"></uc3:Settings>
</ContentTemplate>
</asp:UpdatePanel>
</asp:Panel>
<asp:Panel ID="pnlMenu" runat="server">
<asp:UpdatePanel ID="updpnlMenu" runat="server">
<ContentTemplate>
<uc4:Menu id="Menu" runat="server" CssClass="jQTrackChanges"></uc4:Menu>
</ContentTemplate>
</asp:UpdatePanel>
</asp:Panel>
</form>
Settings.ascx.vb:
Private Sub chkIn_CheckedChanged(sender As Object, e As EventArgs) Handles chkIn.CheckedChanged
RaiseEvent Click(Me, e)
End Sub
Private Sub chkOut_CheckedChanged(sender As Object, e As EventArgs) Handles chkOut.CheckedChanged
RaiseEvent Click(Me, e)
End Sub
Public Event Click As EventHandler
Edit - adding AutoPostBack=false and UpdateMode=Conditional has no effect. All four usercontrols still post back when one does.
Updated main .ASPX:
<asp:Panel ID="pnlOptions" runat="server" AutoPostBack="false">
<asp:UpdatePanel ID="updpnlOptions" runat="server" UpdateMode="Conditional" AutoPostBack="false">
<ContentTemplate>
<uc2:Options id="Options" runat="server" AutoPostBack="false" CssClass="jQTrackChanges"></uc2:Options>
</ContentTemplate>
</asp:UpdatePanel>
</asp:Panel>
<asp:Panel ID="pnlSettings" runat="server" AutoPostBack="false">
<asp:UpdatePanel ID="updpnlSettings" runat="server" UpdateMode="Conditional" AutoPostBack="false">
<Triggers>
<asp:AsyncPostBackTrigger ControlID="Settings" EventName="Click" />
</Triggers>
<ContentTemplate>
<uc3:Settings id="Settings" runat="server" AutoPostBack="false" CssClass="jQTrackChanges"></uc3:Settings>
</ContentTemplate>
</asp:UpdatePanel>
</asp:Panel>
<asp:Panel ID="pnlMenu" runat="server" AutoPostBack="false">
<asp:UpdatePanel ID="updpnlMenu" runat="server" UpdateMode="Conditional" AutoPostBack="false">
<ContentTemplate>
<uc4:Menu id="Menu" runat="server" AutoPostBack="false" CssClass="jQTrackChanges"></uc4:Menu>
</ContentTemplate>
</asp:UpdatePanel>
</asp:Panel>
Please use autopostback property from properties window.change it's default behavior true or false and try again.
We eventually gave up and used Javascript to replace as much of the postback activity as possible to minimize the number of postbacks that happen.
In the below code Changing asyncPostBackTrigger to PostBackTrigger causing the entirepage postback.
But the below code is not at all doing anything when we use the trigger as asyncPostBackTrigger.
Any suggestions about what I am doing wrong??
<%# Page Language="VB" AutoEventWireup="false" CodeFile="Default.aspx.vb" Inherits="_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">
<asp:ScriptManager ID="ScriptManager1" runat="server" />
<asp:UpdatePanel runat="server" ID="UpdatePanel_1" >
<ContentTemplate>
<asp:CheckBox ID="chkNotKnown" runat="server" AutoPostBack="True"
Text="(Not Known)" OnCheckedChanged="chkNotKnown_CheckedChanged"/>
</ContentTemplate>
<Triggers>
<asp:asyncPostBackTrigger ControlID="chkNotKnown"/>
</Triggers>
</asp:UpdatePanel>
<asp:TextBox ID="txtDrCode" runat="server" OnFocus="this.style.borderColor='red'" OnBlur="this.style.borderColor=''"></asp:TextBox>
</form>
</body>
</html>
Partial Class _Default
Inherits System.Web.UI.Page
Protected Sub chkNotKnown_CheckedChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles chkNotKnown.CheckedChanged
With txtDrCode
If chkNotKnown.Checked Then
.Text = "Not Known"
.Enabled = False
Else
.Text = ""
.Enabled = True
End If
End With
End Sub
End Class
The chkNotKnown is inside the UpdatePanel, while txtDrCode is outside of it. Also you specify chkNotKnown as an asyncPostBackTrigger, which is the same as something already present in the UpdatePanel.
So either change the Trigger to a PostBackTrigger (causing a full PostBack)
<Triggers>
<asp:PostBackTrigger ControlID="chkNotKnown" />
</Triggers>
Or place the TextBox inside the UpdatePanel
<asp:UpdatePanel runat="server" ID="UpdatePanel_1">
<ContentTemplate>
<asp:CheckBox ID="chkNotKnown" runat="server" AutoPostBack="True"
Text="(Not Known)" OnCheckedChanged="chkNotKnown_CheckedChanged" />
<asp:TextBox ID="txtDrCode" runat="server"></asp:TextBox>
</ContentTemplate>
</asp:UpdatePanel>
Working with asp.net, I have a gridview inside an update panel, populated with dynamic user controls (loaded in placeholder1 on rowdatabound). A user enters text in a textbox of the user control, clicks the "confirm" button of the user control, a modal popup displays a "confirmation" message with the user's value of the text box. The button click event of the user control handles setting the modal popup extender control values and shows the popup.
This works as expected when the gridview is not in an update panel/no update panel is used. Once I place the gridview in an update panel, when the modal popup appears, it doesn't show the values that were set in the button click event (I've confirmed the click event is firing, controls are being found, and values are getting set in the event). I must be missing something...and/or don't quite understand the architecture of the update panel and how it behaves with dynamic controls.
[code below has been simplified]
GRIDVIEW
<asp:UpdatePanel ID="UpdatePanel1" runat="server">
<ContentTemplate>
<asp:GridView ID="gvSaleData" runat="server" DataKeyNames="ItemNumber"
AutoGenerateColumns="False" ShowFooter="True" />
<Columns>
<asp:TemplateField ShowHeader="false">
<ItemTemplate>
<div>
<asp:PlaceHolder ID="PlaceHolder1" runat="server"></asp:PlaceHolder>
</div>
</ItemTemplate>
</asp:TemplateField>
</Columns>
</asp:GridView>
</ContentTemplate>
</asp:UpdatePanel>
MODAL POPUP
<asp:modalpopupextender id="mp1" runat="server"
cancelcontrolid="btnCancel"
targetcontrolid="btnShow" popupcontrolid="pnlShow"
popupdraghandlecontrolid="PopupHeader" drag="true"
backgroundcssclass="ModalPopupBG">
</asp:modalpopupextender>
<asp:panel id="pnlShow" style="display:none" runat="server">
<div class="popupcontainer">
<div>Your Value: <asp:Label ID="lblUserValue" runat="server" Text=""></asp:Label></div>
<asp:Button ID="btnConfirm" runat="server" Text="Confirm"
onclick="btnConfirm_Click" CssClass="submit"/>
<asp:Button ID="btnCancel" runat="server" Text="Return"
onclick="btnCancel_Click" CssClass="submit"/>
</div>
</asp:panel>
USER CONTROL CODE BEHIND
protected void btnShowConfirmation_Click(object sender, EventArgs e)
{
AjaxControlToolkit.ModalPopupExtender mp =(AjaxControlToolkit.ModalPopupExtender)Page.FindControl("mp1");
Label lblUserValue = (Label)mp.FindControl("lblUserValue");
lblUserValue.Text = textbox1.Text;
mp.Show();
}
I only came across this question recently, a year after it was asked and am posting a solution in case any one else has the same problem.
The answer is to put the the ModalPopupExtender panel "pnlShow" inside an update panel with an AsycPostBackTrigger added whose ID is btnShowConfirmation.
If btnShowConfirmation is dynamically added it should be added to the UpdatePanel dynamically.
The attached example shows two buttons which raise the modal popup. The trigger reference to btnX is added in the aspx code,the btnY triger is added dynamically as an example.
[Aspx code]
<%# Page Language="vb" AutoEventWireup="false" CodeBehind="TestModalPopup.aspx.vb"
Inherits="USSGAinfo.TestModalPopup" %>
<%# Register Assembly="AjaxControlToolkit" Namespace="AjaxControlToolkit" TagPrefix="ajaxToolkit" %>
<!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>
<style type="text/css">
.modalPopupX
{
background-color: #DDFFDD;
border-width: 2px;
border-style: solid;
border-color: black;
padding-top: 20px;
padding-left: 10px;
width: 400px;
height: 150px;
}
</style>
</head>
<body>
<form id="form1" runat="server">
<ajaxToolkit:ToolkitScriptManager ID="ToolkitScriptManager1" runat="server">
</ajaxToolkit:ToolkitScriptManager>
<!-- Hidden Field -->
<asp:UpdatePanel runat="server" ID="up1" ChildrenAsTriggers="false" UpdateMode="Conditional">
<Triggers>
<asp:AsyncPostBackTrigger ControlID="OkButton" />
</Triggers>
<ContentTemplate>
<asp:Button runat="server" ID="btnX" Text="X" />
<asp:Button runat="server" ID="btnY" Text="Y" /><br />
<asp:Label runat="server">Confirm:</asp:Label><asp:Label runat="server" ID="lblResult"></asp:Label>
</ContentTemplate>
</asp:UpdatePanel>
<asp:HiddenField ID="hidForModal" runat="server" />
<ajaxToolkit:ModalPopupExtender ID="MPE" runat="server" TargetControlID="hidForModal"
PopupControlID="pnlTarget" BackgroundCssClass="modalBackground" PopupDragHandleControlID="pnlTarget">
</ajaxToolkit:ModalPopupExtender>
<asp:Panel ID="pnlTarget" Style="display: none" runat="server">
<asp:UpdatePanel runat="server" ID="up2" ChildrenAsTriggers="false" UpdateMode="Conditional">
<Triggers>
<asp:AsyncPostBackTrigger ControlID="btnX" />
<%-- <asp:AsyncPostBackTrigger ControlID="btnY" />--%>
</Triggers>
<ContentTemplate> <asp:Panel runat="server" ID="Panel1" HorizontalAlign="Center" DefaultButton="OkButton"
CssClass="modalPopupX">
<asp:Table runat="server">
<asp:TableRow runat="server">
<asp:TableCell runat="server" ID="tcResult" HorizontalAlign="Center" Width="400px" Height="20px" BackColor="AntiqueWhite">Button Clicked:
<asp:label runat="server" ID="lblMPEResult"></asp:label>
</asp:TableCell>
</asp:TableRow>
</asp:Table>
<br />
<asp:Button ID="OkButton" runat="server" Text="Yes" />
<asp:Button ID="CancelButton" runat="server" Text="No" />
</asp:Panel>
</ContentTemplate>
</asp:UpdatePanel>
</asp:Panel>
</form>
</body>
</html>
[Code behind]
Public Class TestModalPopup
Inherits System.Web.UI.Page
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
' Add btnY as trigger for ModalPopoup update panel
Dim trigger As New AsyncPostBackTrigger
trigger.ControlID = "btnY"
trigger.EventName = "Click"
up2.Triggers.Add(trigger)
End Sub
Private Sub btnX_Click(sender As Object, e As System.EventArgs) Handles btnX.Click
' Put button dependent info into ModalPopup and then show
lblMPEResult.Text = "XXX"
MPE.Show()
End Sub
Private Sub btnY_Click(sender As Object, e As System.EventArgs) Handles btnY.Click
' Put button dependent info into ModalPopup and then show
lblMPEResult.Text = "YYY"
MPE.Show()
End Sub
Private Sub OkButton_Click(sender As Object, e As System.EventArgs) Handles OkButton.Click
' Show that OK button was pressed and also information derived from the ModalPopup
lblResult.Text = lblMPEResult.Text
MPE.Hide()
End Sub
Private Sub CancelButton_Click(sender As Object, e As System.EventArgs) Handles CancelButton.Click
MPE.Hide()
End Sub
End Class
I have a problem with UpdatePanel.I have wrote this simple code:
<asp:ScriptManager ID="ScriptManager1" runat="server">
</asp:ScriptManager>
<asp:UpdatePanel ID="UpdatePanel1" runat="server">
<ContentTemplate>
<asp:Button ID="btn_AddPic" runat="server" OnClick="btn_AddPic_Click" Text="Button" />
</div>
<asp:Label ID="lbl_temp" runat="server" Text=""></asp:Label>
</ContentTemplate>
</asp:UpdatePanel>
I change lbl_temp value by jquery but when I try to read it's value in server side,I show that it's empty.what is the problem?
UpdatePanel is a container. You need to find control inside it:
Dim myValue = DirectCast(Me.UpdatePanel1.FindControl("lbl_temp"), Label).Text
I am using VB.Net and the problem is that my update panel causes full page load no matter how I try. When I download sample codes from website and run, it works!!! Even if I copy the whole codes from those sample into my newly created webform and run, it still refreshes the whole page!! What could be the problem?
PS. I've already tried in my web.config and it didn't make different !! :(
WebForm1.aspx
<%# Page Language="vb" AutoEventWireup="false" CodeBehind="WebForm1.aspx.vb" Inherits="WebApplication1.WebForm1" %>
<%# Register Assembly="System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"
Namespace="System.Web.UI" TagPrefix="asp" %>
<!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 id="Head1" runat="server">
<title>How to use UpdatePanel</title>
</head>
<body>
<form id="form1" runat="server">
<asp:ScriptManager ID="ScriptManager1" runat="server" EnablePartialRendering="true" />
<asp:Label ID="lblTime1" runat="server" /><br />
<asp:Button ID="butTime1" runat="server" Text="Refresh Panel" /><br /><br />
<asp:UpdatePanel ID="UpdatePanel1" runat="server" UpdateMode="Conditional">
<Triggers>
<asp:AsyncPostBackTrigger ControlID="butTime1" EventName="Click" />
<asp:PostBackTrigger ControlID="butTime2" />
</Triggers>
<ContentTemplate>
<asp:Label ID="lblTime2" runat="server" /><br />
<asp:Button ID="butTime2" runat="server" Text="Refresh Page" /><br />
</ContentTemplate>
</asp:UpdatePanel>
<br />
<asp:UpdatePanel ID="UpdatePanel2" runat="server" UpdateMode="Conditional">
<Triggers>
<asp:AsyncPostBackTrigger ControlID="DropDownList1" EventName="SelectedIndexChanged" />
</Triggers>
<ContentTemplate>
<asp:Label ID="lblTime3" runat="server" /><br />
</ContentTemplate>
</asp:UpdatePanel>
<asp:DropDownList ID="DropDownList1" runat="server" AutoPostBack="true">
<asp:ListItem>Change</asp:ListItem>
<asp:ListItem>My</asp:ListItem>
<asp:ListItem>Value</asp:ListItem>
</asp:DropDownList>
</form>
</body>
</html>
WebForm1.aspx.vb
Public Partial Class WebForm1
Inherits System.Web.UI.Page
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
lblTime1.Text = DateTime.Now.ToString("T")
lblTime2.Text = DateTime.Now.ToString("T")
lblTime3.Text = DateTime.Now.ToString("T")
End Sub
End Class