adding events to programatically added controls in web user control - asp.net

I am trying to put a - what seems - very simple web user control
basically i want it to render as a dropdownlist/checkboxlist or radiolist based on a property
but also want to be able to work out what is selected
i was trying the following - but cant seem to work out how to attach to the selectedindexchanged of the listcontrol so that i can set the selectd value(s)
its not helping that my VB is not up to much but am forced to use it in this instance
its not even giving me the intellisense for the event..
Public Options As List(Of Options)
Public ControlRenderType As ControlRenderType
Public IncludeFreeOption As Boolean
Public SelectedOptions As List(Of Options)
Protected Sub Page_Init(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Init
Dim c As ListControl
Select Case (ControlRenderType)
Case STGLib.ControlRenderType.CheckBoxList
c = New CheckBoxList()
Case STGLib.ControlRenderType.DropdownList
c = New DropDownList()
Case STGLib.ControlRenderType.RadioButtonList
c = New RadioButtonList()
Case Else
Throw New Exception("No Render Type Specified")
End Select
For Each opt In Options
Dim li = New ListItem(opt.Description, opt.ID)
c.Items.Add(li)
Next
c.SelectedIndexChanged += ..?? or something
Page.Controls.Add(c)
End Sub
can anyone explain please - it is of course quite possible that I am going about this in completely the wrong way..
thanks

First create a Sub or a Function to handle the IndexChange of the object that you have created dynamically and make sure that the signature of the Sub is something like this
Sub myOwnSub(ByVal sender As Object, ByVal e As EventArgs)
...
... Handle your event here
...
End Sub
Then after you create your object add the following code
Dim obj as ListBox
AddHandler obj.SelectedIndexChanged, AddressOf myOwnSub

Related

Filtering a datasource on Click Event

I have a datasource which is specified on Page_Load :
// EmpDetailsList query to get employee data
EmpGridView.DataSource = EmpDetailsList
EmpGridView.DataBind()
I am trying to filter the datasource when the user clicks a button;
Protected Sub Search_btn_Click(sender As Object, e As EventArgs) Handles Search_btn.Click
FilteredList = EmpDetailsList.Where(EmpDetailsList.FirstName= "John")
EmpGridView.DataSource = FilteredList
EmpGridView.DataBind()
End Sub
I am having a lot of trouble doing this without using EmpDetailsList as a global variable.
I also do not want to violate the DRY principle and call the data source a second time when the search button is clicked. I also tried passing EmpDetailsList as a parameter to another Sub but I don't understand how to use it with a click event handler.
Any suggestions will be helpful, I've looked for a couple of hours but I haven't found anything that doesn't use global variables.
The Where function expects a predicate. Add a .ToList at the end so your have a List(Of T) instead of an IEnumerable.
Protected Sub Search_btn_Click(sender As Object, e As EventArgs) Handles Search_btn.Click
Dim FilteredList = (EmpDetailsList.Where(Function(e) e.FirstName = "John")).ToList
EmpGridView.DataSource = FilteredList
EmpGridView.DataBind()
End Sub

CommandArgument on SQLDatasource Inserted?

I'm wishing to redirect to two different pages depending on which button is pressed on my form.
Both buttons call the Insert method of the Datasource, but only one of them needs to get hold of the newly inserted GUID and redirect using that GUID.
I'm doing it using this code
Protected Sub DSCustomers_Inserted(sender As Object, e As SqlDataSourceStatusEventArgs) Handles DSCustomers.Inserted
Response.Redirect("~/addTicket.aspx?step=2&customerID=" & e.Command.Parameters("#customerID").Value.ToString)
End Sub
But how can I know if it's the other button that has been pressed and doesn't need to redirect?
I can't get access to the CommandArgument otherwise I would just check which button has been pressed using that and then redirect accordingly.
Thanks
You can't just use a global private boolean?
Dim RedirectButtonPressed As Boolean = false
Protected Sub RedirectButton_Click(sender As Object, e As EventArgs) Handles RedirectButton.Clicked
// code code code
RedirectButtonPressed = True
End Sub
Protected Sub DSCustomers_Inserted(sender As Object, e As SqlDataSourceStatusEventArgs) Handles DSCustomers.Inserted
If RedirectButtonPressed Then
Response.Redirect("~/addTicket.aspx?step=2&customerID=" & e.Command.Parameters("#customerID").Value.ToString)
RedirectButtonPressed = False
End If
End Sub

Failure to update textbox.text

I have a relatively simple ASP.NET problem (I should think) that regrettably I am unable to solve by myself. What I am trying to do is the following:
On a page I load a number of controls (Text Boxes) programmatically;
following this load the user should be able to select a value to load into the Textbox from a panel control that is added to the page following the click of a button
Once the panel is closed, the selected text from the panel should be loaded into the textbox
However, in the vb.net statements below when run the "test" string never makes it to the textbox - any help with resolving this would be greatly appreciated.
Public Class test
Inherits System.Web.UI.Page
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
Controls_Load()
End Sub
Public Sub Controls_Load()
Dim ttf_tb As New TextBox With {.ID = "ttf_tb"}
Master_Panel.Controls.Add(ttf_tb)
Dim ttf_button As New Button
Master_Panel.Controls.Add(ttf_button)
AddHandler ttf_button.Click, AddressOf TTF_BUTTON_CLICK
End Sub
Public Sub TTF_BUTTON_CLICK(sender As Object, e As EventArgs)
Dim str As String = sender.id
Dim panel As New Panel
panel.ID = "TTF_Panel"
panel.Width = 300
panel.Height = 300
Master_Panel.Controls.Add(panel)
panel.BackColor = Drawing.Color.Black
panel.Style.Add(HtmlTextWriterStyle.Position, "absolute")
panel.Style.Add(HtmlTextWriterStyle.Left, "200px")
panel.Style.Add(HtmlTextWriterStyle.Top, "100px")
panel.Style.Add(HtmlTextWriterStyle.ZIndex, "100")
Dim CL_Button As New Button
CL_Button.ID = "TTF_Close_" & Replace(str, "TTF_Button_", "")
panel.Controls.Add(CL_Button)
AddHandler CL_Button.Click, AddressOf TTF_Close_Button_Click
End Sub
Public Sub TTF_Close_Button_Click(sender As Object, e As EventArgs)
Dim ttf_tb As TextBox = Master_Panel.FindControl("ttf_tb")
ttf_tb.Text = "Test"
Dim panel As Panel = FindControl("TTF_Panel")
Master_Panel.Controls.Remove(panel)
End Sub
End Class
I think you need to re-create your controls in the Page_Init method. It's been a while since I've done web forms but I think it's something like:
When a user clicks the button a post back is fired. This re-creates a new instance of your class, creates the controls on the page, assigns any form values then calls your Page_Load event.
The problem is you are creating your controls too late, so the forms values are never assigned correctly.
You should create / recreate your dynamic controls in the Init event:
Protected Sub Page_Init(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Init
Controls_Load()
End Sub
This should allow you to maintain their state across PostBacks.
For more information about this topic, see the MSDN article on the ASP.NET Page Life Cycle.

Web Controls Not Talking to Each other in ASP.NET using VB.NET

I have an asp.net page that loads two controls, Control A and Control B. Control A has some generic form submit and clear buttons that trigger click events in its' own code behind which use reflection to call the update function in Control B which has a few input fields. I have debugged this and everything seems to be in order, however; when the update function in control B is called the input fields are not returning a value when using inputname.text or me.inputname.text. Does anyone have any ideas why this is not working? Any guidance would be appreciated.
This is the code in Control A's codebehind which calls the update method in Control B's code behind
Protected Sub btnSave_Click(ByVal sender As Object, ByVal e As EventArgs) Handles btnSave.Click
Try
Dim lctlControl = Session("SelectedQstnCtl")
Dim methodObj = lctlControl.GetType().GetMethod("UpdateGenInfo", BindingFlags.NonPublic Or BindingFlags.Instance)
' Execute UpdateGenInfo method to update the data
methodObj.Invoke(lctlControl, Nothing)
Catch ex As Exception
'TODO: check for concurrency error here
End Try
End Sub
This is the update function in Control B that is being called. The session values are being passed, but the form fields are not.
Protected Sub UpdateGenInfo()
Dim lclUtil As New clUtility
Dim genInfo As New clGenInfo
Try
Dim dt As Integer
'Update Data for 1-2
dt = genInfo.UpdateGenInfo_E1_01_02(Session("ConnStrEP"), Me.varLastUpdate, Session("AppNo"), Session("RevNo"), _
Me.txtPrName.Text, Me.txtPrAddr1.Text, Me.txtPrAddr2.Text, _
Me.txtPrCity.Text, Me.txtPrState.Text, Me.txtPrZip.Text)
Catch ex As Exception
'Display error
lclUtil.DisplayMsg(Me.lblErrMsg, String.Format("Error Location: Sub LoadGenInfo (ctlE1_01_02) {0}", ex.Message))
End Try
End Sub
The most likely cause is that the control instance stored in the session is not the control instance on the current page. For example, if you're storing the control instance in the session when the page is first loaded, and retrieving it on post-back, it will be a different instance.
If you can't give Control A a direct reference to Control B, then change your code to store the reference in the Page.Items collection:
Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)
Page.Items("SelectedQstnCtl") = TheSelectedQstnCtl
End Sub
Protected Sub btnSave_Click(ByVal sender As Object, ByVal e As EventArgs) Handles btnSave.Click
Dim lctlControl = DirectCast(Page.Items("SelectedQstnCtl"), YourControlClass)
lctlControl.UpdateGenInfo()
End Sub
I see you are using reflection which might be an overkill for that task.Try referencing the method in the control directly.Make then method UpdateGenInfo public and then reference it like this.
Protected Sub btnSave_Click(ByVal sender As Object, ByVal e As EventArgs) Handles btnSave.Click
Try
Dim lctlControl = CType(Session("SelectedQstnCtl"),YourControlClass)
lctlControl.UpdateGenInfo()
Catch ex As Exception
End Sub
Public Function UpdateGenInfo()
'your code here
Catch ex As Exception
End Try
End Function
This way you can easily trace where your values are getting lost.Let me know how it goes.
Try yet another simple approach working demo here
In control a
Protected Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim testb1 = CType(Me.NamingContainer.FindControl("testb1"), testb)
testb1.UpdateGenInfo()
End Sub
In control b
Public Function UpdateGenInfo()
Try
Dim a = Me.TextBox1.Text
Catch ex As Exception
End Try
End Function
Aspx Parent Page
<uc1:testa ID="testa1" runat="server" />
<uc2:testb ID="testb1" runat="server" />
The controls in testb are in an update panel.Try this and let me know if this works.

VB.Net ListView Select Item with Button

Note: There was not any question with this kind of problem here or anywhere...
Ok, so I made my listview, and it's delete and edit events are working properly, now I want to implement a possibility for user to mark an element as "default".
D, E and Def are buttons
Reference
----------------------------------------------------------------
- ref1 - somevalue - somevalue - somevalue - [D] - [E] - [Def]
----------------------------------------------------------------
so that would be a row from a table, I made delete and edit work by handling events from listview,
Private Sub lvMain_ItemDelete(ByVal sender As Object, ByVal e As ListViewDeleteEventArgs) Handles lvMain.ItemDeleting
Dim refFac As new ReferenceFactory
refFac.Delete(e.Keys(0))
EndSub
similar for Editing. But now when I try to get values from Default button, the button wont even do anything...
This is the code:
<asp:ImageButton ID="ibtDefault" runat="server" ImageUrl="~/Images/Default16.png" CommandName="Default" />
and for my logic:
Public Sub ibtDefault_Click(ByVal sender As Object, ByVal e As ImageClickEventArgs )
SelectedRef.Name = "Test"
End Sub
I just wanted to test it whether it will run or not by changing the value of my global string that will show which Reference is made default. But it wont even do that...
Then I tried with Commands.
Private Sub lvMain_ItemCommand(ByVal sender As Object, ByVal e As ListViewCommandEventArgs) Handles lvMain.ItemCommand
If e.CommandName = "Default" Then
'Dim refID As New Integer
'Dim refer As ListViewItem
'refer = e.Item
SelectedRef.Name = "Test"
End If
End Sub
But this wont run either... What am I doing wrong here :S
Basically what I want to is that on click i save Reference Name and ID in two global variables i prepared.
Thanks
Default is a reserved word and may be messing with your code. When you run through your ItemCommand event, you can rebind the data at the end of it and it should refresh your page.

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