I've been racking my brain trying to get this to work. My event for my LinkButton isn't firing. I'm figuring that it has SOMETHING to do with ViewState and that the button is not there when it tries to fire the event after the Postback or something.
When I click the Add button,it adds the link to the page and then when I click the Diplay Time" linkbutton it should fire the event and display the CommandArgument data but it's not and i can't figure out why.
Here's my code:
<%# Page Language="VB" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs)
End Sub
Protected Sub btnDelete_OnCommand(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.CommandEventArgs)
Response.Write(e.CommandArgument)
End Sub
Protected Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs)
Dim btn As New LinkButton()
btn.ID = "lbn"
btn.Text = "Display Time"
btn.ValidationGroup = "vgDeleteSigner"
AddHandler btn.Command, AddressOf btnDelete_OnCommand
btn.CommandArgument = Now.TimeOfDay.ToString()
btn.EnableViewState = True
Panel1.Controls.Add(btn)
End Sub
</script>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title></title>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:Button ID="Button1" runat="server" Text="Button" OnClick="Button1_Click" />
<asp:Panel ID="Panel1" runat="server">
</asp:Panel>
</div>
</form>
</body>
</html>
The reason that's happening is that your dynamic button "lbn" needs to be drawn again on post back when it's clicked because the button doesn't exist after you click it.
Basically you just have to dynamically add the button to the page again on post back of click of that button.
I would recommend having the button already on the page but visible = false and then just showing it when you click the other button.
Related
I can see the date population on the web page. However, it is not showing up in the TextBox. I need the calendar date selected to show up on the TextBox.
Below is my Default.aspx code:
<%# Page Language="VB" %>
<script runat="server">
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs)
TextBox1.Focus()
End Sub
Protected Sub Calendar1_SelectionChanged(ByVal sender As Object, ByVal e As System.EventArgs)
Response.Write("You selected: " &
Calendar1.SelectedDate.ToShortDateString())
End Sub
</script>
<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
<title>Using the Calendar Control</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
<asp:Calendar ID="Calendar1" runat="server"
OnSelectionChanged="Calendar1_SelectionChanged">
</asp:Calendar>
</div>
</form>
</body>
</html>
Change the line:
Response.Write("You selected: " & Calendar1.SelectedDate.ToShortDateString())
to:
TextBox1.Text = Calendar1.SelectedDate.ToShortDateString()
I am using Visual Studio 2010, VB.NET, target framework .NET 4.0.
I have a GridView which I am binding to some object collection, with a CommandField column that should allow edit of the selected row.
I am setting the EditIndex property correctly in the RowEditing eventhandler.
The problem is: When I click the "Edit" link that is generated, nothing apparently happens, the row gets rendered again in "view mode", not "edit mode".
But if I do some random postback, like clicking my "doNothing" button, the row gets rendered in "edit mode" in the next postback.
I have managed to reproduce the problem in the following code:
ASPX:
<%# Page Language="vb" AutoEventWireup="false" CodeBehind="MyForm.aspx.vb" Inherits="MySandBox.MyForm" %>
<%# Register Src="MyControl.ascx" TagName="MyControl" TagPrefix="uc1" %>
<!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:GridView ID="gvInfrator" runat="server" AutoGenerateColumns="false">
<Columns>
<asp:CommandField ShowEditButton="true" />
<asp:BoundField HeaderText="MyField" DataField="MyField" />
</Columns>
</asp:GridView>
<asp:Button ID="btnDoNothing" runat="server" Text="Just do a postback" />
</form>
</body>
</html>
Code Behind:
Public Class MyDto
Public Property MyField As String
End Class
Public Class MyForm
Inherits System.Web.UI.Page
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
Me.BindMyData()
End Sub
Private Sub BindMyData()
Dim myData As New MyDto
myData.MyField = "My field value"
Me.gvInfrator.DataSource = New MyDto() {myData}
Me.gvInfrator.DataBind()
End Sub
Protected Sub gvInfrator_RowEditing(sender As Object, e As System.Web.UI.WebControls.GridViewEditEventArgs) Handles gvInfrator.RowEditing
Me.BindMyData()
Me.gvInfrator.EditIndex = e.NewEditIndex
End Sub
End Class
Am I doing something wrong? Is this a bug in .NET Framework 4? Is there any workaround?
You need to bind your data after you set the EditIndex of your GridView.
Protected Sub gvInfrator_RowEditing(sender As Object, e As System.Web.UI.WebControls.GridViewEditEventArgs) Handles gvInfrator.RowEditing
Me.gvInfrator.EditIndex = e.NewEditIndex
Me.BindMyData()
End Sub
I am looking to update one of my DDL's functionality by making it dynamically update so if the user adds more files, the drop down will pick this up.
At present my drop down list is pulling from VB code behind, as shown below:
Public Sub DDL_SelectedIndexChanged(sender As Object, e As EventArgs)
Dim ddl As DropDownList = CType(sender, DropDownList) 'item is already dropdownlist
Dim ctl As TextBox = DirectCast(ddl.NamingContainer.FindControl("eTemplate"), TextBox)
If ddl.SelectedValue = 1 Then
ctl.Text = File.ReadAllText("e:Documents\Visual Studio 2013\Projects\Web\Templates\Down.txt")
ElseIf ddl.SelectedValue = 2 Then
ctl.Text = File.ReadAllText("e:Documents\Visual Studio 2013\Projects\Web\Templates\Up.txt")
Else
ctl.Text = ""
End If
End Sub
At the moment I have hard coded in the functionality for the VB to grab specific .txt files, how can I get this to update dynamically from a folder of .txt files?
Thanks for looking.
Here is some sample code for you. This demo uses an UpdatePanel and a Timer to refresh the DropdownList every 5 seconds.
Add a new aspx file to your Web Application and the following code:
<%# Page Language="VB" AutoEventWireup="false" CodeFile="Demo.aspx.vb" Inherits="Zpk_Test2" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html dir="ltr" xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Asynchronous Update Demo</title>
</head>
<body>
<form id="form1" runat="server">
<asp:ScriptManager runat="server" ID="ScriptManager1" />
<asp:UpdatePanel runat="server" ID="UpdatePanel1">
<ContentTemplate>
<asp:DropDownList ID="DropDownList1" runat="server" AutoPostBack="true" /><br />
<asp:Timer runat="server" ID="Timer1" Interval="5000" Enabled="true" />
</ContentTemplate>
<Triggers>
<asp:PostBackTrigger ControlID="DropDownList1" />
</Triggers>
</asp:UpdatePanel>
<asp:TextBox ID="TextBox1" runat="server" TextMode="MultiLine" Width="300" Height="250" />
</form>
</body>
</html>
This is the code-behind:
Partial Class Demo
Inherits System.Web.UI.Page
Private Const FolderName As String = "C:\Temp" '<-- replace with your folder name
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
If Not IsPostBack Then
RefreshDropDownList()
OpenSelectedFile()
End If
End Sub
Private Sub Timer1_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Timer1.Tick
' this event is fired everytime a timer ticks.
' refresh your dropdown list here.
RefreshDropDownList()
End Sub
Protected Sub DropDownList1_SelectedIndexChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles DropDownList1.SelectedIndexChanged
OpenSelectedFile()
End Sub
Private Sub RefreshDropDownList()
Dim currentSelected As String = DropDownList1.SelectedValue
DropDownList1.DataSource = IO.Directory.GetFiles(FolderName, "*.txt").Select(Function(f) IO.Path.GetFileName(f)).ToList
DropDownList1.DataBind()
DropDownList1.SelectedValue = currentSelected
End Sub
Private Sub OpenSelectedFile()
Dim fileName As String = IO.Path.Combine(FolderName, DropDownList1.SelectedValue)
TextBox1.Text = IO.File.ReadAllText(fileName)
End Sub
End Class
Ok, I have been going around and around with this for hours (Searching, etc). This is what I want to do, I want to load data into a Text Box and if the user changes the text in the Text Box I want to be able to save the new text.
My problem in the TxtBox_TextChanged event the data contained in the txtNarrative Text box is the new data that the user typed in (<>ABCD) but in the btnSubmit_Click event the data contained in txtNarrative is the original value ABCD.
What am I doing wrong??
<%# Page Language="vb" AutoEventWireup="false" CodeBehind="Default.aspx.vb" Inherits="WorkBench_VBNet._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">
<div>
<fieldset>
<span class="title">Entry Form</span>
<ul class="pageitem">
<li class="Narrative">
<asp:TextBox EnableViewState=true ID="txtNarrative" placeholder="Narrative" Width="100%"
Rows="10" TextMode="multiline" runat="server" Height = "100%" OnTextChanged="TxtBox_TextChanged" >
</asp:TextBox></li>
<li class="Submit">
<asp:LinkButton ID="btnSubmit" runat="server">Submit</asp:LinkButton>
</li>
</ul>
</fieldset>
</div>
</form>
</body>
</html>
Code Behind:
Public Class _Default
Inherits System.Web.UI.Page
Public Event TextChanged As EventHandler
Protected Sub TxtBox_TextChanged(ByVal sender As Object, _
ByVal e As System.EventArgs) Handles txtNarrative.TextChanged
ViewState("txtNarrative") = txtNarrative.Text ''<-- The text here is the changed text not ABCD
txtNarrative.Text = ViewState("txtNarrative").ToString
End Sub
Private Sub btnSubmit_Click(sender As Object, e As System.EventArgs) Handles btnSubmit.Click
Dim Narrative as String = txtNarrative.Text '<-- the text in the text box is still ABCD not what was changed.
''Code to update data in the Database goes here
End Sub
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
If Not IsPostBack Then
txtNarrative.Text = "ABCD"
End If
End Sub
End Class
Get rid of the TxtBox_TextChanged Sub, it's not needed, the IPostBackDataHandler of the TextBox will do that for you:
<asp:TextBox EnableViewState=true ID="txtNarrative" placeholder="Narrative" Width="100%"
Rows="10" TextMode="multiline" runat="server" Height = "100%" >
</asp:TextBox>
I'm not sure if I understand your question but:
You do not need to "OnTextChanged" textbox in your markup.
In your code behind you alredy have handles declaration.
If you use both ("OnTextChanged" on your html markup, and handles in your code behind) the text box event will trigger twice.
Protected Sub TxtBox_TextChanged (ByVal sender As Object, _
ByVal e As System.EventArgs) Handles txtNarrative.TextChanged
ViewState ("txtNarrative") = txtNarrative.Text''<-- The text here text is not changed the ABCD
txtNarrative.Text = ViewState ("txtNarrative"). ToString
end Sub
<asp: TextBox EnableViewState = true ID = "txtNarrative" placeholder = "Narrative" Width = "100%"
Rows = "10" TextMode = "multiline" runat = "server" Height = "100%">
</ asp: TextBox>
also tested your code and the value that is submitted is the new value in the textbox. (Ie if I understand your question)
Hope this helps
I am trying to figure out how to declaratively pass in a event handler into
a user control, but I am stumped. All I can make work is the user control's
event handler.. I can't seem to bubble up the caught event into the parent
page. Ideas would be quite welcome. Here is my code:
Default.aspx:
<%# Page Language="VB" %>
<%# Register TagPrefix="rpt" TagName="filter" Src="WebUserControl.ascx" %>
<!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>Test Controls</title>
</head>
<body>
<form id="form1" runat="server">
<rpt:filter ID="DataView1Filters" runat="server" SelectedIndexChanged="DropDown_SelectedIndexChanged" />
<asp:Label ID="Label1" runat="server" />
</form>
<script runat="server">
Public Sub DropDown_SelectedIndexChanged(ByVal sender As Object, ByVal e As EventArgs)
Label1.Text = String.Format("Inside declarative event handler. {0}<br>", Label1.Text)
End Sub
</script>
</body>
</html>
WebUserControl.ascx:
<%# Control Language="VB" ClassName="WebUserControlTest" %>
<asp:Panel ID="TestPanel" runat="server"></asp:Panel>
<script runat="server">
Private AllEvents As New System.ComponentModel.EventHandlerList
Public Custom Event SelectedIndexChanged As EventHandler
AddHandler(ByVal value As EventHandler)
AllEvents.AddHandler("SelectedIndexChanged", value)
End AddHandler
RemoveHandler(ByVal value As EventHandler)
AllEvents.RemoveHandler("SelectedIndexChanged", value)
End RemoveHandler
RaiseEvent(ByVal sender As Object, ByVal e As System.EventArgs)
Dim value As EventHandler = CType(AllEvents("SelectedIndexChanged"), EventHandler)
If Not value Is Nothing Then
value.Invoke(sender, e)
End If
End RaiseEvent
End Event
Private Sub _SelectedIndexChanged(ByVal sender As Object, ByVal e As EventArgs)
Dim ctrl As DropDownList = Me.FindControl("TestDropDownList")
If Not ctrl Is Nothing Then
Me.ViewState("ItemSelection") = ctrl.SelectedIndex
End If
Dim Label1 As Label = Parent.FindControl("Label1")
Label1.Text = String.Format("Inside user control event handler. {0}<br>", Label1.Text)
RaiseEvent SelectedIndexChanged(sender, e)
End Sub
Private Overloads Sub OnLoad(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
Dim ctrl As New DropDownList
With ctrl
.ID = "TestDropDownList"
.Items.Clear()
.AutoPostBack = True
AddHandler .SelectedIndexChanged, AddressOf _SelectedIndexChanged
.Items.Add(New ListItem("-- Select --", String.Empty))
.Items.Add(New ListItem("Item 1", "1"))
.Items.Add(New ListItem("Item 2", "2"))
If Not Me.ViewState("ItemSelection") Is Nothing Then
.SelectedIndex = CInt(Me.ViewState("ItemSelection"))
Else
.SelectedIndex = 0
End If
End With
TestPanel.Controls.Add(ctrl)
End Sub
</script>
Thanks!
See this previous post:
Handling User Control Events on Containing Page
Edit - added based on your comment
I should have read the question more clearly.
As far as having a UserControl raise an event that the containing page can respond to, I do not believe that this can be done declaratively.
Unless my knowledge is just lacking, the only way to accomplish this is by explicitly creating an event in the control and then handling it (by coding the event handler) on the parent page, as shown in the example I linked to.
I was recently having this same issue in C#. When you set up an event called SelectedIndexChanged asp.net will bind the attribute OnSelectedIndexChanged when using the declarative syntax.
So if you change
<rpt:filter ID="DataView1Filters" runat="server" SelectedIndexChanged="DropDown_SelectedIndexChanged" />
To
<rpt:filter ID="DataView1Filters" runat="server" OnSelectedIndexChanged="DropDown_SelectedIndexChanged" />
It should work.