So I wanted to make my textbox in asp.net to postback every time a text it typed onto it but i cant seem to figure out how. Does any one knows? here is the code of the event handler
Private Sub TextBox2_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles txtFiltrarNomeUtente.TextChanged
If chkFiltroUtente.Checked And Me.cbxLocal.Text <> "" Then
Me.loadFormInfo()
End If
End Sub
and the textbox
<asp:TextBox ID="txtFiltrarNomeUtente" runat="server" AutoPostBack="true">
so any ideas on how to do it? thanks
You need to add the OnTextChanged event to TextBox txtFiltrarNomeUtente.
<asp:TextBox ID="txtFiltrarNomeUtente" runat="server" AutoPostBack="true" OnTextChanged="TextBox2_TextChanged"></asp:TextBox>
Related
I have a very simple Textbox and Button, but Button click event not firing at first time ( only firing in second click)
<asp:TextBox ID="TxtSurvey" runat="server"></asp:TextBox> <br />
<asp:Button ID="BtnGoSurvey" runat="server" Text="LetsGo"/>
The code is very simple too
Protected Sub BtnGoSurvey_Click(sender As Object, e As EventArgs) Handles BtnGoSurvey.Click
Session("IDSurvey") = TxtSurvey.Text
BtnGoSurvey.PostBackUrl = "~/Survey.aspx"
End Sub
What i'm doing wrong ?
Thanks for help
If you can use Response.Redirect, then following is supposed to work:
Protected Sub BtnGoSurvey_Click(sender As Object, e As EventArgs) Handles BtnGoSurvey.Click
Session("IDSurvey") = TxtSurvey.Text
Response.Redirect("~/Survey.aspx",True)
End Sub
I am using label control in form designing.But i want to hide that particular label control on page load.
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
Label10.Visible = False
End Sub
What should i do? I'm new to vb.net.
Try setting the visibility property within the aspx code rather than within the load event, this may solve your issue.
<asp:Label ID="lblValidation" runat="server" BackColor="Red"
Text="Please fill in all of the date fields below to proceed" Visible="False"></asp:Label>
Hope this helps!
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
...
I'm trying to make a tabbed menu for the asp.net website I'm working on. One of the pre-requisite is obviously to color the current tab differently, so the user can know on which tab is currently is.
To do this, I made this method in my code-behind:
Protected Function GetCssClass(ByVal ctrl As LinkButton) As String
If ctrl.ID = currentLink Then
Return "current"
Else
Return String.Empty
End If
End Function
and I call the method like this in my aspx page:
<asp:LinkButton ID="LinkButton1" runat="server" PostBackUrl="/Default.aspx" CssClass="<%#GetCssClass(LinkButton1) %>" >Home</asp:LinkButton>
<asp:LinkButton ID="LinkButton2" runat="server" PostBackUrl="/Directory/page1.aspx" CssClass="<%#GetCssClass(LinkButton2) %>" >Page1</asp:LinkButton>
But the method is never hit... As I understand, the method should be called each time the LinkButton is drawn...
Does someone have an idea why?
Thanks in advance !
Edit: Just as a precision, all this code is in the masterpage.
Edit2: Here are the changes I made according to Quagland's suggestion.
In the aspx masterpage:
<asp:HiddenField ID="currentLink" runat="server" />
<asp:LinkButton ID="LinkButton1" runat="server" PostBackUrl="/Default.aspx" OnClick="LinkButton_Click" OnPreRender="LinkButton_PreRender" >Home</asp:LinkButton>
<asp:LinkButton ID="LinkButton2" runat="server" PostBackUrl="/OtherDirectory/Page1.aspx" OnClick="LinkButton_Click" OnPreRender="LinkButton_PreRender" >Page1</asp:LinkButton>
<asp:LinkButton ID="LinkButton3" runat="server" PostBackUrl="/OtherDirectory/Page2.aspx" OnClick="LinkButton_Click" OnPreRender="LinkButton_PreRender" >Page2</asp:LinkButton>
<asp:LinkButton ID="LinkButton4" runat="server" PostBackUrl="/OtherDirectory/Page3.aspx" OnClick="LinkButton_Click" OnPreRender="LinkButton_PreRender" >Page3</asp:LinkButton>
And in the code behind:
Protected Sub LinkButton_Click(ByVal sender As Object, ByVal e As EventArgs) Handles LinkButton1.Click, LinkButton2.Click, LinkButton3.Click, LinkButton4.Click, LinkButton5.Click, LinkButton6.Click, LinkButton7.Click, LinkButton8.Click
Dim lnk As LinkButton = CType(sender, LinkButton)
currentLink.Value = lnk.ID
End Sub
Protected Function GetCssClass(ByVal ctrl As LinkButton) As String
If ctrl.ID = currentLink.Value Then
Return "current"
Else
Return String.Empty
End If
End Function
Protected Sub LinkButton_PreRender(ByVal sender As Object, ByVal e As EventArgs) Handles LinkButton1.PreRender, LinkButton2.PreRender, LinkButton3.PreRender, LinkButton4.PreRender, LinkButton5.PreRender, LinkButton6.PreRender, LinkButton7.PreRender, LinkButton8.PreRender
Dim lnk As LinkButton = CType(sender, LinkButton)
lnk.CssClass = GetCssClass(lnk)
End Sub
The problem is now that the click event is not always fired. On first click, nothing happens, but on second click on a tab, the click event is correctly triggered. Any clue ?
Edit3: Could it be that the value stored in the hidden field is reset each time the masterpage is reloaded (I mean, each link points to a couple masterpage + content page) ?
You need to use <%= ... %> (i.e. replace # with =).
The hash form is used with data binding, you want to just create output.
For .NET 4 prefer <%: ... %> (use a colon) to automatically do HTML encoding.
I have quickly tested a solution that might work for you. I'm just not sure where your 'currentlink' variable comes from. I have implemented it as a hidden field here.
In Masterpage.aspx:
<asp:HiddenField ID="currentLink" runat="server" />
<asp:LinkButton ID="LinkButton1" runat="server">Home</asp:LinkButton>
<asp:LinkButton ID="LinkButton2" runat="server">Page1</asp:LinkButton>
In code behind:
use your original GetCssClass function add this:
Protected Sub LinkButton_PreRender(ByVal sender As Object, ByVal e As System.EventArgs)
Handles LinkButton1.PreRender, LinkButton2.PreRender
Dim lnk As LinkButton = CType(sender, LinkButton)
lnk.CssClass = GetCssClass(lnk)
End Sub
I have put it in PreRender because i was using the LinkButton click events to set the hidden field value (and Click happens after Load but before PreRender):
Protected Sub LinkButton_Click(ByVal sender As Object, ByVal e As System.EventArgs) _
Handles LinkButton1.Click, LinkButton2.Click
Dim lnk As LinkButton = CType(sender, LinkButton)
currentLink.Value = lnk.ID
End Sub
also, if there are numerous Linkbuttons, you may want to declare like:
<asp:LinkButton ID="LinkButton1" runat="server" OnClick="LinkButton_Click" OnPreRender="LinkButton_PreRender">Home</asp:LinkButton>
EDIT:
Here is another solution that will work with cross page postbacks. Not much code but you'll need to put some on every page. Anyway:
Masterpage.aspx:
<asp:LinkButton ID="LinkButton1" runat="server" PostBackUrl="Default.aspx">Home</asp:LinkButton>
<asp:LinkButton ID="LinkButton2" runat="server" PostBackUrl="Page1.aspx">Page1</asp:LinkButton>
<asp:LinkButton ID="LinkButton3" runat="server" PostBackUrl="Page2.aspx">Page2</asp:LinkButton>
<asp:LinkButton ID="LinkButton4" runat="server" PostBackUrl="Page3.aspx">Page3</asp:LinkButton>
Masterpage.aspx.vb:
Public Sub SetCssClass(ByVal ctrl As String)
CType(FindControl(ctrl), LinkButton).CssClass = "current"
End Sub
All content pages:
*.aspx:
add this directive to create a strongly typed reference to the masterpage
<%# MasterType VirtualPath="~/MasterPage.master" %>
*.aspx.vb:
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
Master.SetCssClass("LinkButton1") '' << put the name of the relevant link button here
End Sub
Set the CssClass in the code-behind. This will state your intent more clearly than calling DataBind on your linkbuttons if you use databinding syntax. Since you're doing it for multiple controls maybe stick them in a method called ApplyCssClasses.
I'm not sure why <%= %> isn't working but personally I don't like to mix code and markup, I like to keep them completely separate.
I would suggest setting the CSS class in code perhaps on the page load event.
lnkPopulate.CssClass = "current"
<%# ... %> will work if you're OK with doing LinkButton1.DataBind() in your code-behind at the appropriate time.
I must be doing something wrong. I can't seem to execute my CustomValidator's ServerValidate method.
I've got a Visual Basic ASP.NET page with a CustomValidator...
<asp:TextBox ID="TextBox1" runat="server" />
<asp:CustomValidator ID="CustomValidator1" runat="server"
ControlToValidate="TextBox1"
ErrorMessage="Friendly message goes here."
Display="Dynamic" />
<asp:Button ID="Button1" runat="server"
Text="Submit"
CausesValidation="True" />
For this test, I've got the validation set to always fail...
Sub CustomValidator1_ServerValidate(ByVal source As Object, ByVal args As System.Web.UI.WebControls.ServerValidateEventArgs) Handles CustomValidator1.ServerValidate
args.IsValid = False
End Sub
But, when the button is clicked, the CustomValidator1_ServerValidate() method never executes!
Protected Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Page.Validate()
If Page.IsValid Then
'it executes the code here!
End If
End Sub
Not even if I explicitly validate that control...
CustomValidator1.Validate() 'does nothing?
What am I doing wrong?
Add the property:
ValidateEmptyText="True"
Are you putting the validator control submit button in the same validation group?
Firstly, You seem to be missing the OnServerValidate attribute in your markup above.
Secondly, I would check to ensure that CustomValidator1_ServerValidate has been set up as an eventhandler for the ServerValidate event for Textbox1. I have had occasions where I have changed the name of the validate method in the markup and code-behind, but the IDE has not auto updated the subscribing method name passed to the eventhandler delegate
I know it's a daft question (or might sound like it!). But have you actually entered or changed the value in the textbox? I think the validator won't trigger without the contents of the textbox changing.