How do i set the visible property of a Link button inside update panel inside master page from a content page.
This I have done inside a click event of command button without luck
dim showLnk as Linkbutton =ctype(master.findcontrol("updatepanel1").findcontrol("lnkLogOut",LinkButton)
showLnk.visible =true.
Let's say you have this code inside the Master page:
<asp:UpdatePanel ID="updatepanel1" runat="server">
<ContentTemplate>
<asp:Panel runat="server" ID="parentPanel">
<asp:LinkButton ID="lnkLogOut" runat="server">Logout</asp:LinkButton>
</asp:Panel>
</ContentTemplate>
</asp:UpdatePanel>
To set the visibility from a content page simply do this:
Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
Dim showLnk As LinkButton = Master.FindControl("lnkLogOut")
showLnk.Visible = False
End Sub
Related
I have a simple test app with a MasterPage, a Default.aspx page containing an UpdatePanel with few html and asp controls.
My purpose is to create dynamically controls and bind events.
I know the issue about IDs on controls and binding event handlers, as the the fact that you need to register an asynccontrol to the scriptmanager.
I tried many things but my dynamically created linkbutton goes in PostBack, in the MasterPage on_load but NEVER in my attached click event.
Extra infos : the declarative asp button triggers its click event after Default.aspx Page_Load and performing a Postback, the LinkButton dynamically created goes as well in the Default Page_Load but never trigger btnTest_Click2. This app is on .NET 4.5 (Visual Studio 2015).
Any idea ?
Thx.
Default.aspx :
<%# Page Title="Home Page" Language="VB" MasterPageFile="~/Site.Master" AutoEventWireup="false" CodeBehind="Default.aspx.vb" Inherits="TestUpdatePanel._Default" %>
<asp:Content ID="BodyContent" ContentPlaceHolderID="MainContent" runat="server">
<h1>This will never change !</h1>
<asp:UpdatePanel ID="UpdatePanel1" runat="server" UpdateMode="Conditional">
<ContentTemplate>
<asp:Button runat="server" ID="btnTest" CssClass="btn btn-success" OnClick="btnTest_Click" Text="Hit me hard !" />
<div runat="server" id="testDiv">
<p>Hello this a test</p>
</div>
</ContentTemplate>
<Triggers>
</Triggers>
</asp:UpdatePanel>
</asp:Content>
Default.aspx.vb code-behind :
Public Class _Default
Inherits Page
Dim currentsm As ScriptManager
Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
currentsm = CType(Page.Master.FindControl("sm1"), ScriptManager)
If Not IsPostBack Then
MsgBox("It's not a postback", MsgBoxStyle.DefaultButton1)
Else
MsgBox("It's a Postback !", MsgBoxStyle.DefaultButton1)
End If
End Sub
Protected Sub btnTest_Click(sender As Object, e As EventArgs)
BuildButton()
End Sub
Private Sub BuildButton()
Dim link = New LinkButton
link.ID = "linkTest"
link.ClientIDMode = ClientIDMode.Static
link.Text = "This is a new Ajax link :-)"
AddHandler link.Click, AddressOf btnTest_Click2
Dim trigger As AsyncPostBackTrigger = New AsyncPostBackTrigger
trigger.ControlID = link.ClientID
trigger.EventName = "Click"
UpdatePanel1.Triggers.Add(trigger)
currentsm.RegisterAsyncPostBackControl(link)
testDiv.Controls.Add(link)
UpdatePanel1.Update()
End Sub
Private Sub BuildDiv()
Dim divToCreate = New HtmlGenericControl
divToCreate.TagName = "div"
divToCreate.ID = "newDiv"
divToCreate.ClientIDMode = ClientIDMode.Static
divToCreate.Attributes("class") = ("btn btn-alert")
divToCreate.InnerText = "It works !"
testDiv.Controls.Add(divToCreate)
UpdatePanel1.Update()
End Sub
Protected Sub btnTest_Click2(sender As Object, e As EventArgs)
BuildDiv()
End Sub
I finally got it with the use of the OnInit event to instanciate the dynamically created controls like this :
Protected Overrides Sub OnInit(e As EventArgs)
MyBase.OnInit(e)
If IsPostBack Then
currentsm = CType(Page.Master.FindControl("sm1"), ScriptManager)
Dim sender = Request.Form("__EVENTTARGET").ToString
If sender.Contains("btnTest") Then
BuildButton()
ElseIf sender.Contains("linkTest") Then
BuildDiv()
End If
End If
End Sub
so i want to have a button the changes the text of a label when i click it and it says page not available, but when i comment out the update panel it atleast shows up.
<form id="form1" runat="server">
<asp:ScriptManager ID="s1" runat = "server"></asp:ScriptManager>
<div>
<h1>UpDaTe PaNeL tEsT PaGe</h1>
start text : Hello <br />
updated text: World<br />
<hr />
<asp:UpdatePanel ID="p1" runat="server">
<ContentTemplate>
<asp:Button ID="Button1" runat="server" Text="Update" OnClick="updateLabel" Height="29px" Width="110px"/> -->
Text: <asp:Label ID="Label1" runat="server" Text="hello"></asp:Label>
</ContentTemplate>
</asp:UpdatePanel>
</div>
</form>
codebehind
Public Class aaaa
Inherits System.Web.UI.Page
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
End Sub
Function updatelabel() As String
Label1.Text = "World"
End Function
End Class
The previous answer is correct. The handler for the Label Click event needs the sender as Object and the e as EventArgs parameters. If you do not put them, your updateLabeL() function will not be a valid match for the event handler.
You can remove the OnClick from the button and Try the classic method of handling events.
So your code will be... ( Sorry I'm posting it via app so it might not be in code view )
Protected Sub ChangeLabel(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click
Label1.text = "TextGoesHere"
End Sub
I have a .aspx page that contains a hidden panel that I need to display from a .ascx control.
On my .Click event from my button on my .ascx I have the following:
Dim myControl2 As Control = FindControl("Content1")
Dim myControl3 As Control = FindControl("keywordSearchModal")
On my .aspx I have the following:
<asp:Content ID="Content1" ContentPlaceHolderID="ContentHolder" runat="server">
<asp:Panel ID="keywordSearchModal" runat="server" Width="800px" Visible="true">
This is your modal
<asp:Button ID="OKButton" runat="server" Text="Close" />
</asp:Panel>
</asp:Content>
Both myControl2 and myControl3 contain nothing when the button is clicked.
How can I find this control from the .ascx that also happens to be an updatepanel.
UPDATE
I was able to find the control by doing the following:
Dim myPanel As Panel = Page.Master.FindControl("ContentHolder").FindControl("keywordSearchModal")
myPanel.Visible = False
Dim myControl As Control = Page.Master.FindControl("ContentHolder").FindControl("keywordSearchModal")
myControl.Visible = False
I was able to use the ContentPlaceHolderID - However now I can't change the visibility...
UPDATE II
thanks to the suggestion below I was able to capture the button click on my .aspx page. However, now just like before I can't seem to manipulate the control. In this example adding text to the panel.
Protected Sub SearchStart(ByVal sender As Object, ByVal e As EventArgs) Handles EquipmentDetails1.SearchStart
Dim newLabel As New Label
newLabel.Text = "This is a label!"
keywordSearchModal.Controls.Add(newLabel)
End Sub
Thoughts?
Here is what I've used in the past...
My user control has an imagebutton and the following in the codebehind
Public Event SearchStart As EventHandler
'This will be the event triggered when the imagebutton is clicked
Protected Sub ib_Search_Click(ByVal sender As Object, ByVal e As EventArgs) Handles ib_Search.Click
'Bubble up event to parent
RaiseEvent SearchStart(Me, e)
End Sub
Any page that uses the User Control will have the following in codebehind...
Protected Sub mc_SearchFilter_SearchStart(ByVal sender As Object, ByVal e As EventArgs) Handles mc_SearchFilter.SearchStart
'CODE that needs to be executed when search image button is clicked in my_control_SearchFilter
End Sub
Hope that helps....
I'm attempting to use Controls.AddAt(), but it apparently breaks controls at later indexes:
Here's my minimal example:
Aspx put in a form:
<asp:DropDownList runat="server" ID="ddl" />
<asp:Button Text="text" runat="server" OnClick="Unnamed2_Click" />
Code Behind:
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
If Not IsPostBack Then
ddl.Items.Add("Click the button")
'Controls.Add(New HyperLink) 'Works fine, but is put at end of collection.
'Controls.AddAt(2 ,New HyperLink) 'Is also safe but I wanted the control first
Controls.AddAt(0, New HyperLink) 'ddl loses it's item after postback
End If
End Sub
On the first postback of the page after calling AddAt, the DropDownList loses it's item. It doesn't matter what kind of control I add even HTMLControls. Viewstate is not disabled.
How do I dynamically add controls without breaking others?
If you used a PlaceHolder to add your HyperLink into, it would not mess up the rest of the page:
<asp:PlaceHolder ID="PlaceHolder1" runat="server"></asp:PlaceHolder>
<asp:DropDownList ID="ddl" EnableViewState="true" runat="server" />
<asp:Button ID="bn1" Text="text" OnClick="Unnamed2_Click" runat="server" />
With code like
Protected Sub Unnamed2_Click(sender As Object, e As EventArgs) Handles bn1.Click
Dim newItem = "Click the button" & DateTime.Now.ToString("HH:mm:ss")
ddl.Items.Add(newItem)
ddl.SelectedIndex = ddl.Items.Count - 1
PlaceHolder1.Controls.Add(New HyperLink With {.ID = "hyp", .Text = "Hyperlink here"})
End Sub
And always give your asp:Controls an ID if they take one.
I am experiencing a problem with buttons and AddHandler. It only works if I use AddHandler Button1.click, AddressOf... in Page_load, but if I create the button dynamically in one of the sub routines, the event doesn't fire.
For example,
<asp:Label ID="Label1" runat="server" Text="Label"></asp:Label>
<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"></asp:ScriptManager>
<asp:UpdatePanel id="UpdatePanel1" runat="server" UpdateMode="Conditional" ChildrenAsTriggers="False">
<contenttemplate>
<asp:PlaceHolder id="PlaceHolder1" runat="server"></asp:PlaceHolder>
</contenttemplate>
</asp:UpdatePanel>
<asp:UpdatePanel id="UpdatePanel2" runat="server" UpdateMode="Conditional">
<contenttemplate>
<asp:Label id="Label2" runat="server" Text="Label"></asp:Label>
</contenttemplate>
</asp:UpdatePanel>
Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
Label1.Text = Date.Now
ScriptManager1.RegisterAsyncPostBackControl(DropDownList1)
End Sub
Protected Sub Button1_Click(ByVal sender As Object, ByVal e As EventArgs)
Label2.Text = "Panel refreshed at " + Date.Now.ToString()
End Sub
Protected Sub DropDownList1_SelectedIndexChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles DropDownList1.SelectedIndexChanged
Dim b As New Button
b.Text = "Click"
ScriptManager1.RegisterAsyncPostBackControl(b)
AddHandler b.Click, AddressOf Button1_Click
PlaceHolder1.Controls.Add(b)
UpdatePanel1.Update()
End Sub
The dropdownlist works, but the button doesn't. What am I doing wrong?
You have to regenerate your dynamically created controls on every postback (at last in Page_Load, better in Page_Init). You have to set the ID of the controls accordingly because ASP.Net needs it to identify which control caused a Postback and to handle the appropriate events.
You could save the number of created buttons in ViewState and use this to regenerate them on Page_Load. Increase the number when you add a new button. Use this number also to make the Button's ID unique(append it to the ID) to ensure that its the same on every postback.
For further informations, have a look the Page-Lifecycle and ViewState with dynamically added controls.
Edit: As Joel commented, if you only need one Button you can set it's ID statically, but you have to regenerate it on postback f.e. to handle its click-event.
Just to aid anyone who has this problem and isn't quite sure how to implement. Here's a quick example.
This example starts out by displaying a dropdownlist. When user selects something from the dropdown, another dropdownlist appears.
I typed this off the top of my head, so it MAY contain errors, but you get the idea =)
In the aspx file, add a placeholder:
And in your codebehind:
...
Protected Sub Page_Init(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Init
'Store control count in viewstate
If Not IsPostBack Then ViewState("ControlCounter") = 1
'Rebuild dynamic controls on every postback so when page's life cycle hits Page_Load,
'selected values in the viewstate (asp.net default behavior) can be loaded into the dropdowns
Build_Dynamic_Controls()
End Sub
Protected Sub Build_Dynamic_Controls()
'Clear placeholder
myPlaceholder.Controls.Clear()
'This is where the control counter stored in the viewstate comes into play
For i as Integer = 0 To CInt(ViewState("ControlCounter") -1
Dim ddlDynamic as New DropDownList With {
.ID = "ddlDynamicDropdown" & i,
.AutoPostBack = True
}
'This is the event that will be executed when the user changes a value on the form
'and the postback occurs
AddHandler ddlDynamic.SelectedIndexChanged, AddressOf ddlDynamic_SelectedIndexChanged
'Add control to the placeholder
myPlaceholder.Controls.Add(ddl)
'Put some values into the dropdown
ddlDynamic.Items.Add("Value1")
ddlDynamic.Items.Add("Value2")
ddlDynamic.Items.Add("Value3")
Next i
End Sub
Protected Sub ddlDynamic_SelectedIndexChanged(ByVal sender As Object, ByVal e As System.EventArgs)
'When a dropdown value is changed, a postback is triggered (autopostback=true)
'The event is captured here and we add another dropdown.
'First we up the control count:
ViewState("ControlCounter") = CInt(ViewState("ControlCounter")) + 1
'Now that the "total controls counter" is upped by one,
'Let's recreate the controls in the placeholder to include the new dropdown
Build_Dynamic_Controls()
End Sub
...