Changing Controls of a form inside a panel - vb.net

Question

I am facing a weird problem
I have 3 forms: MainForm, Form1, Form2
MainForm has 1 Panel: Panel1
Form1 has 1 Label: NameLbl and Button: ChangeBtn
Form2 has 1 textbox: NameTxt and Button: SaveBtn
I used the following code to open form1 inside Panel1 in mainform
Panel1.Controls.Clear()
Dim FormInPanel As New Form1()
FormInPanel.TopLevel = False
Panel1.Controls.Add(FormInPanel)
FormInPanel.Show()
On ChangeBtn.Click Form2 opens as showdialog
I want NameLbl.text to change to NameLbl.text when SaveBtn is clicked But normal code doesnt work.
Private Sub SaveBtn_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles SaveBtn.Click
Form1.NameLbl.text=NameTxt.text
End Sub
What Should I do? Any suggestions? Given that i need to open the forms in panels for certain reasons.
Please keep in mind that this is just an example. I have multiple controls in Form1 which i want to change on form2.SaveBtn.click
I have also tried this but it does nothing
Private Sub SaveBtn_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles SaveBtn.Click
For Each c As Control In MainForm.Panel1.Controls(0).Controls
If c.Name="NameLbl" Then
c.Text = NameTxt.Text
End If
Next
End Sub
Please Somebody tell me how it do it!

Answer 1

Form2 doesn't seem to have any connection back to Form1 or MainForm. You'd need to raise an event from Form2 which MainForm handles or another class handles and can pass to MainForm
Edit:
Sorry, I've just seen how you're calling Form2. There are lots of ways to get a value back from Form2 after calling ShowDialog(). One is to create a property called Result and check Result if ShowDialog() == DialogResult.OK. Something like the following.
Public Class Form2
Inherits System.Windows.Forms.Form
Public Property Result() As String
Get
Return m_Result
End Get
Set
m_Result = Value
End Set
End Property
Private m_Result As String
End Class
Public Class Form1
Inherits System.Windows.Forms.Form
Public ChangeBtn As Button
Public NameLbl As Label
Public Sub New()
Me.ChangeBtn = New Button()
AddHandler Me.ChangeBtn.Click, AddressOf ChangeBtn_Click
Me.NameLbl = New Label()
End Sub
Private Sub ChangeBtn_Click(sender As Object, e As EventArgs)
Dim form As New Form2()
Dim dr = New form.ShowDialog()
If dr = DialogResult.OK Then
Me.NameLbl.Text = form.Result
End If
End Sub
End Class
I'd like to add that if you plan on growing this application much larger you'll run into issues with maintenance. Look into some patterns for dealing with UI logic like MVC, MVP, MVVM if you're interested.

Answer 2

you can try this code:
Private Sub SaveBtn_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles SaveBtn.Click
panel1.Controls(0).NameLbl.text=NameTxt.text '"0" is the index of forminpanel in panel1,maybe it need to change.
End Sub

Answer 3

Form1 is contained in Panel1, so you can not access it via
Form1.
Only MainForm is visible from Form2:
Private Sub SaveBtn_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles SaveBtn.Click
For Each c As Control In MainForm.Panel1.Controls(0).Controls
If TypeOf c Is TextBox Then
c.Text = NameTxt.Text
End If
Next
End Sub

Answer 4

Try this:
For Each form1 As Form1 In MainForm.OwnedForms.OfType(Of Form1)
Form1.NameLbl.text = NameTxt.text
Next

Answer 5

I've faced same issue and I've fixed with this
Dim f As FormInPanel
f = Form.Panel1.Controls(0)
f.transection = True
f.NameLbl.text=NameTxt.text