Multiple Child Forms behaving strangely - vb.net

I have created a Form that dynamically loads buttons into a panel on the left hand side of an MDI Parent Form. Once loaded, a user can click one of the buttons, and a Child form will load into the right hand side, docked at the top and containing a datagridview with the results of some query. Each child form that is added sits directly below the previous one, due to the docking top property.
All this seems to work fine, however when more than one child forms is open the behaviour of the forms is unexpected. If I click on any child form other than the bottom form, it immediately moves its position to the bottom, rather than staying in place. Is there a way to deal with this - or is there something I am doing in my code that means this is happening - such as trying to dock a window?
My code is below.
Private Sub TableLookupForm_Load(sender As Object, e As EventArgs) Handles MyBase.Load
Dim mySQLString As String = "Button SQL Query"
Dim i As Integer = 0
myVector.mySQLString = mySQLString
For Each row In myVector.myIngresDataset.Tables(0).Rows
Dim myBtn As New Button
i = i + 1
myBtn.Text = row("table_name")
myBtn.Name = "Btn" & i
myBtn.Dock = DockStyle.Top
AddHandler myBtn.Click, AddressOf Me.Button_Click
Me.Panel1.Controls.Add(myBtn)
Me.Panel1.Controls.SetChildIndex(myBtn, 0)
Next
End Sub
Private Sub Button_Click(ByVal sender As System.Object, ByVal e As System.EventArgs)
Dim myTableForm As New TableChildForm
myTableForm.MdiParent = Me
myTableForm.Dock = DockStyle.Top
myTableForm.Tag = sender.text
myTableForm.Text = sender.text
Dim mySQLString As String = "Form SQL Query"
myVector.mySQLString = mySQLString
myTableForm.myTableData.DataSource = myVector.myIngresDataset.Tables(0)
myTableForm.Show()
End Sub
Thanks,
Paul.

Related

Button Array - how to pass a parameter to shared handler

I have a bit of code where i have a dynamically created array or buttons with staff pictures on them, as well as the staff's name. I've added one handler to handle any button click from any of the buttons. where i am stuck is, if you look at the code below, it all works fine, and if you click any of the buttons you get the "aha" test message. but i want the name of the staff clicked on (so btnArray(i).Text) to be passed to the handler for further processing. I tried adding a ByVal parameter to the handler but that caused an error. what's the correct way to do this? As i said, the code below works for me, i just am at a loss as to how to add the extra functionality.
Dim btnArray(staffcount) As System.Windows.Forms.Button
For i As Integer = 1 To staffcount - 1
btnArray(i) = New System.Windows.Forms.Button
btnArray(i).Visible = True
btnArray(i).Width = 80
btnArray(i).Height = 101
btnArray(i).BackgroundImage = Image.FromFile(picloc(i))
btnArray(i).BackgroundImageLayout = ImageLayout.Stretch
btnArray(i).Text = staffname(i)
Dim who As String
who = btnArray(i).Text
AddHandler btnArray(i).Click, AddressOf Me.theButton_Click
btnArray(i).ForeColor = Color.White
btnArray(i).TextAlign = ContentAlignment.BottomCenter
Dim fnt As Font
fnt = btnArray(i).Font
btnArray(i).Font = New Font(fnt.Name, 10, FontStyle.Bold)
FlowLayoutPanel1.Controls.Add(btnArray(i))
Next i
End Sub
Private Sub theButton_Click()
MsgBox("aha")
End Sub
First, correct the signature of your shared handler.
Private Sub theButton_Click(sender As Object, e As EventArgs)
End Sub
Once that is done getting the text of the button clicked is a simple matter.
Private Sub theButton_Click(sender As Object, e As EventArgs)
Dim textOfButtonClicked As String = DirectCast(sender, Button).Text
MessageBox.Show(textOfButtonClicked)
End Sub
The sender is the button that was clicked. Since signatures use objects for the sender the DirectCast 'changes' it to button and you then can access the .Text property of the button.
If there are more manipulations you want to perform on the clicked button you could do it this way
Private Sub theButton_Click(sender As Object, e As EventArgs)
Dim whBtn As Button = DirectCast(sender, Button) ' get reference to button clicked
Dim textOfButtonClicked As String = whBtn.Text
MessageBox.Show(textOfButtonClicked)
'e.g. change the color
whBtn.BackColor = Color.LightYellow
End Sub

Update text in dynamically created label

I'm working on a proof of concept type situation that will eventually be tied to a scheduling database. As a Test I created this:
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
'AddButton("test")
addLots()
End Sub
Private Sub AddLots()
Dim x As Integer
For x = 0 To 10
Dim b As New Button
Dim newLabel As New Label
newLabel.Location = New Point(100, x * 20)
newLabel.Name = x
newLabel.BorderStyle = BorderStyle.Fixed3D
newLabel.Text = newLabel.Name
Me.Controls.Add(newLabel)
Me.Controls.Add(b)
b.Location = New Point(20, x * 20)
b.Text = x
b.Tag = x
b.Name = x
AddHandler b.Click, AddressOf Button_Click
Next
End Sub
Private Sub Button_Click(ByVal sender As Object, ByVal e As System.EventArgs)
Dim B As Button = sender
MsgBox(B.Name)
End Sub
For this proof of concept, I simply want label 1 text to be updated when I press button 1 seems like a simple process but it's kicking my butt.
As for any object, to affect a Label you will need a reference to it. As it stands, the only reference you have is via the Controls collection of the parent control you added the Label to, i.e. the form itself. You could loop through the Controls of the form and as soon as you find a Label then you know you have the first one, or you could call OfType and First or FirstOrDefault. That assumes that there are no other Label controls on the form.
You might also consider using a dedicated parent control so that you know it will only contain the Label controls you created at run time. The obvious choice would be a TableLayoutPanel because it will handle the layout for you too.
If accessing the dynamic controls via a Controls collection is an issue then keep your own collection. Declare a member variable of type List(Of Label) and add each Label you create to it. You can then access your control from that collection and know that there are no other controls in there to get mixed up with.
By the way, if you're creating those controls at run time then they won't be automatically disposed when the form is. Make sure that you dispose them yourself and also use RemoveHandler for each AddHandler you used.
Actually, looking closer at your code, I just realised that there's a 1:1 correspondence between the Button and Label controls. It would make sense to use that. Two options are to assign the corresponding Label to the Tag of each Button or else use a Dictionary(Of Button, Label) assigned to a member variable to store the relationships. That way, you can then use the sender in the event handler, which will be the Button that was clicked, to get the corresponding Label.
Option 1.
Creating the Label:
Dim btn As New Button
Dim lbl As New Label
btn.Tag = lbl
In the event handler:
Dim btn = DirectCast(sender, Button)
Dim lbl = DirectCast(btn.Tag, Label)
Option 2.
At class level:
Private labelsByButton As New Dictionary(Of Button, Label)
Creating the Label:
Dim btn As New Button
Dim lbl As New Label
Me.labelsByButton.Add(btn, lbl)
In the event handler:
Dim btn = DirectCast(sender, Button)
Dim lbl = Me.labelsByButton(btn)
I added this to the button click event. Doesn't seem very efficient as I will eventually have 30-40 buttons and controls on the form but it works.
Private Sub Button_Click(ByVal sender As Object, ByVal e As System.EventArgs)
Dim B As Button = sender
Dim lblToChange As Integer = B.Name
For Each objCtrl As Control In Me.Controls
If TypeOf objCtrl Is Label Then
Dim Lbl As Label = DirectCast(objCtrl, Label)
If Lbl.Name = lblToChange Then
Lbl.Text = "This ONe"
End If
End If
Next
End Sub

Open Tabs Control

I'm using MDI container to run my bussiness application I created for my client.
Since using MDI means that when I open several forms they will still run in background all the time untill I close them manualy.
What I need is to make User Control or anything else that could preview all opened forms in Tab Form so my client can easily close all or some of opened forms without closing a form he is curently viewing.
For now I have used this code, so for now only first clicked item from menu appears as button, but not others clicked menu items.
Private Sub MenuStrip1_ItemClicked(ByVal sender As System.Object, ByVal e As System.Windows.Forms.ToolStripItemClickedEventArgs) Handles MenuStrip1.ItemClicked
Dim Button As New Button
Me.Panel5.Controls.Add(Button)
Button.Text = e.ClickedItem.Name
Button.Width = 50
Button.Height = 25
End Sub
Now I need to write a code to add more buttons bellow, also should add a code for adding buttons only when I click on SubMenu item (The one when is clicked new Form appear).
And also, I should now add a little Close button into previewed User-Button-Control.
From your comments, I understand that your ideas regarding adding buttons at runtime are not too clear and thus I am including a small code which hopefully will help you on this front. Start a new project and put a Panel (Panel5) and a Button (AddButtons) on it, and write this code:
Dim lastButtonIndex, lastLeft, lastTop As Integer
Private Sub Button_Click(sender As System.Object, e As System.EventArgs)
Dim curButton As Button = DirectCast(sender, Button)
If (curButton.Name = "Button1") Then
'do Button1 stuff
End If
'etc.
End Sub
Private Sub addNewButton()
lastButtonIndex = lastButtonIndex + 1
lastLeft = lastLeft + 5
lastTop = lastTop + 5
Dim Button As New Button
With Button
.Name = "Button" + lastButtonIndex.ToString()
.Text = "Button" + lastButtonIndex.ToString()
.Width = 50
.Height = 25
.Left = lastLeft
.Top = lastTop
AddHandler .Click, AddressOf Button_Click
End With
Me.Panel5.Controls.Add(Button)
End Sub
Private Sub ButtonAddButtons_Click(sender As System.Object, e As System.EventArgs) Handles AddButtons.Click
addNewButton()
End Sub
This code will add a new button to the panel every time you click on AddButtons. All the buttons will have an associated Click Event (the same one for all of them): Button_Click. The way to know which button is the current one inside this method is via sender, as shown in the code (you can put as many conditions as buttons. The names are given sequentially starting from 1; but you can take any other property as reference, curButton is the given Button Control).
Bear in mind that one of the problems you have to take care of is the location of the buttons. The code above has a very simplistic X/Y values (Left/Top properties) auto-increase which, logically, will not deliver what you want.

Programmatically setting properties of controls on tab pages of a tabcontrol

I am working with a tabcontrol on which I create page one with the designer. I am creating new tab pages with controls on the pages programmatically. On each page is a several panels, each with two radiobuttons (one yes,another no). There is a panel nested inside the first panel with its visible property set to false. If the user selects yes, I want the nested panel's visible property set to true which will reveal several more radiobuttons from which they must make more choices.
My problem is in changing the nested panel's property on any page other than page one.. I can detect the radiobuttons, but I can't seem to find a way to make the nested panel visible.
Public Class ControlProgram
Dim pageindx as integer
Private Sub btnAddPrgm1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnAddPrgm1.Click
Dim newTab As New TabPage()
pageindx = (TabControl1.TabPages.Count + 1)
newTab.Text = "Step " & pageindx
'define fill panel controls
Dim newpnlFill As New Panel
Dim newlblFill As New Label
Dim newFillY As New RadioButton
AddHandler newFillY.CheckedChanged, AddressOf CheckforCheckedChanged
Dim newFillN As New RadioButton
AddHandler newFillN.CheckedChanged, AddressOf CheckforCheckedChanged
'add fill panel controls
With newTab.Controls
.Add(newpnlFill)
With newpnlFill
.Location = New System.Drawing.Point(6, 6)
.Size = New System.Drawing.Size(171, 137)
.BorderStyle = BorderStyle.FixedSingle
.Controls.Add(newlblFill)
With newlblFill
.Name = "Fill"
.Text = "Fill ?"
.Font = New Font(newlblFill.Font, FontStyle.Bold)
.Location = New Drawing.Point(5, 3)
End With
.Controls.Add(newFillY)
With newFillY
.Name = "FillY"
.Text = "Yes"
.Location = New Drawing.Point(23, 28)
.Size = New System.Drawing.Size(43, 17)
End With
.Controls.Add(newFillN)
With newFillN
.Name = "FillN"
.Text = "No"
.Location = New Drawing.Point(88, 28)
.Size = New System.Drawing.Size(39, 17)
End With
.Controls.Add(newpnlFill2)
With newpnlFill2
.Location = New System.Drawing.Point(2, 60)
.Size = New System.Drawing.Size(164, 68)
.BorderStyle = BorderStyle.FixedSingle
.Visible = False
End With
End With
End With
Private Sub CheckforCheckedChanged(ByVal sender As Object, ByVal e As System.EventArgs)
If TypeOf sender Is RadioButton Then
bEvent = CType(sender, RadioButton).Name
End If
End Sub
End Class
I have since figured out a solution to my delima, using your suggestions as a starting point.
I added a few varribles:
Dim rb as Control
Dim bEvent as String
Dim booFillY as Boolean
Dim booFillN as Boolean
I also added the TabControl
TabControl1.TabPages.Add(newTab)
I also made these changes :
Private Sub CheckforCheckedChanged(ByVal sender As Object, ByVal e As System.EventArgs)
If TypeOf sender Is RadioButton Then
rb = sender
bEvent = CType(sender, RadioButton).Name
If bEvent = "FillY" Then
Dim newpnlFill2 As Panel = rb.Parent.Controls(3)
newpnlFill2.Visible = True
End If
If bEvent = "FillN" Then
Dim newpnlFill2 As Panel = rb.Parent.Controls(3)
newpnlFill2.Visible = False
End If
End If
End Sub
Now I can make the nested panel(newpnlFill2) visible or not visible by cicking the Yes or No radiobuttons on any of the tab pages created.
thanks for your help. I doubt I would have ever gotten there on my own.
Might not be quite what you were looking for, but should be helpful get you where you need to go.
When I create an application, I like to build a list of all the controls for a given page in the load event so I can access them at any point. This is helpful because WinForms can be very picky about showing you child controls within a tabpage or groupbox, etc.
'Declare this variable within the class for your form (whatever)
Public arrControlsRecursive As New List(Of Control)
'method to recursively check all controls and build to array
Private Sub BuildControlsArrayRecursive(ByVal InControl As Control)
For Each con As Control In InControl.Controls
If con.Controls.Count > 0 Then
BuildControlsArrayRecursive(con)
End If
If TypeOf con Is Control Then
arrControlsRecursive.Add(con)
End If
Next
End Sub
'Call from MyBase.Load Event
BuildControlsArrayRecursive(Form1)
You can also just assemble a list of all tabs, for example, by changing the If statement to Is TypeOf con Is TabPage
Now you can loop through this collection or query it with LINQ. Find a single control by calling the first or single method. Cast to the type you want and do anything to any control anywhere within your form.
I don't really understand what you want to access, you first talk about
changing the nested panel's property on any page other than page one
So I assume you want to access to the other tabs, then, you talk about:
I can't seem to find a way to make the panel visible
Anyway, here's the two solutions:
Access other panels:
Private Sub CheckforCheckedChanged(ByVal sender As Object, ByVal e As System.EventArgs)
If TypeOf sender Is RadioButton Then
bEvent = CType(sender, RadioButton).Name '**Where is "bEvent" declared??**
Dim newpnlFill2 as Panel = bEvent.Parent.Controls(3), Panel)
newpnlFill2.Visible = bEvent.Checked
End If
End Sub
You access to Parent that will be newpnlFill, then access to Controls(3) that it should be newpnlFill2.
Access other tabs:
Private Sub CheckforCheckedChanged(ByVal sender As Object, ByVal e As System.EventArgs)
If TypeOf sender Is RadioButton Then
bEvent = CType(sender, RadioButton).Name '**Where is "bEvent" declared??**
Dim TabControl as TabControl = bEvent.Parent.Parent.Parent, TabControl)
'Then, you can access all of the other tabs with:
'TabControl.TabPages(n)
End If
End Sub
This assume that somewhere you add your newTab to a TabControl.
I see that you never add newTab to any TabControl, so you'll never see it..
The first Parent will be newpnlFill, the second one will reference to newTab and the last one is the TabControl that hold the Tab.
Anyway, it's something really gross, cause it assumes that your Tab is always created in this manner. For example, if you will add another panel before newpnlFill, it will not be the 4th Control in the Panel anymore, so you need to change you access code.
My advice is to create your own UserControl that inherit from TabPage, in this way you can create private variables that will always reference to the Panels you want to change. Moreover, the btnAddPrgm1_Click event will be much more clear, moving the build of the page in your class constructor.
Something like:
Private Sub btnAddPrgm1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnAddPrgm1.Click
Dim newTab As New MyTabPage()
pageindx = (TabControl1.TabPages.Count + 1)
newTab.Text = "Step " & pageindx
TabControl1.TabPages.Add(newTab)
End Sub

How to add event handler to a dynamically created control in VB.NET?

I have searched and seen countless samples here in this forum and in other sites but I'm still stuck with this problem;
I want to add a Click Handler for dynamically created PictureBox-es and pas an argument on it so I know which one of picture boxes was clicked).
Here is my current code:
Public Class frmMbarimAbonimi
Private Sub frmMbarimAbonimi_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
'TODO: This line of code loads data into the 'FitnessdbDataSet.clients' table. You can move, or remove it, as needed.
'Me.ClientsTableAdapter.Fill(Me.FitnessdbDataSet.clients)
'===============
Dim dt As DataTable = PaPaguar()
Dim i As Integer = 0
Dim gr(dt.Rows.Count) As GroupBox
Dim pp(dt.Rows.Count) As PictureBox
Dim lb(dt.Rows.Count) As Label
For Each row As DataRow In dt.Rows
gr(i) = New GroupBox
gr(i).Width = 200
gr(i).Height = 180
pp(i) = New PictureBox
pp(i).SizeMode = PictureBoxSizeMode.StretchImage
lb(i) = New Label
'-------------------------
Try
Using str As Stream = File.OpenRead("C:\Fotot\" + dt.Rows(i).Item("Foto"))
pp(i).Image = Image.FromStream(str)
End Using
lb(i).Text = dt.Rows(i).Item("Emer")
Catch ex As Exception
MsgBox("Fotoja nuk mund te ngarkohet, ju lutem realizoheni nje foto tjeter!!!")
End Try
'-------------------------
pp(i).Visible = True
pp(i).Width = 200
pp(i).Height = 150
AddHandler pp(i).Click, AddressOf testini
gr(i).Controls.Add(pp(i))
lb(i).Visible = True
lb(i).Width = 200
lb(i).Height = 30
lb(i).Left = pp(i).Left
lb(i).Top = pp(i).Top + 150
lb(i).BackColor = Color.WhiteSmoke
lb(i).BringToFront()
gr(i).Controls.Add(lb(i))
flpanel.Controls.Add(gr(i))
i = i + 1
Next row
End Sub
End Class
So I was trying to use AddHandler pp(i).Click, AddressOf testini but obviously this does not allow me to call "testini" with a parameter to identify which picture box was clicked.
Can someone point me in the right direction or give some advice? Greatly appreciated.
You need to add something to your created PictureBox to identify them in the event handler because you can't change the signature of the click event handler adding a 'parameter'
For example, you could set the Name property
pp(i) = New GroupBox
pp(i).Name = "PictureBox" + i.ToString
then in the event handler you could recognize your picture box casting the sender object to a picturebox and grabbing the Name property.
Remember, sender is always the control that triggers the event. In your case is always one of your dinamically created PictureBoxes
Private Sub testini(sender As Object, e As System.EventArgs)
Dim pb As PictureBox = DirectCast(sender, PictureBox)
Dim pbIdentity As String = pb.Name
.....
End Sub