How to change controls from another form in visual basic

Question

How to change controls from another form in visual basic

José Carlos 886

Hi friends,

I have a main form that has a panel with Dock = left and another panel in the same form with Dock = Fill.

On the left panel I have buttons as an options menu.

When I click on a button, I call another form within the Dock=fill panel of the main form.

What am I not able to do? When I click on the menu button I call a form, which is loading perfectly, and I would like to activate a textbox and a picturebox in the called form.

I've already made several attempts using ChatGpt, which has already provided me with two different codes, but none of them worked.

How to do this? Was I clear?

Anonymous

Hi

Here is an example of opening a second Form with control properties changed (.Text, .BackgroundImage) from the first Form.

Option Strict On
Option Explicit On
Public Class Form1
	Dim nf2 As New Form2

	' define an image just to show in nf2
	Dim TestImage As Image = Image.FromFile("C:\Users\lesha\Desktop\ABS.jpg")

	Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
		With nf2
			.PictureBox1.BackgroundImage = TestImage

			' set some example text in TextBox on nf2
			.TextBox1.Text = "First Open"

			.Show()
		End With
	End Sub
End Class

José Carlos 886 Reputation points

2023-10-08T16:49:22.4533333+00:00

Your example worked perfectly in a new project. In my project, it didn't work. When I click on the button to activate the controls on form2, form2 is already loaded on the screen within a panel on form1.

I used the same technique you showed me. There is no error, but the controls are not being activated.

Would the fact of loading form2 inside a Panel in form1 be the problem?

Tks

Anonymous

Hi

Ah, you are putting it into a Panel on Main Form.

Give this example a try and see if it helps. This example uses 2 random images and Buttons 1 & 2 swap the Form in the Panel and Buttons 3 & 4 set the Text in the TextBox of whichever Form is in the Panel.

The Project has a second Form named Form2 which has the TextBox1 and PictureBox1 on it via the Designer with their various properties set as needed.

111

' 2 random images used
Option Strict On
Option Explicit On
Public Class Form1
	Dim nf As New Form2
	Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
		Text = "THIS IS FORM1"
	End Sub
	Private Sub Button_Click(sender As Object, e As EventArgs) Handles Button1.Click, Button2.Click

		Panel1.Controls.Clear()
		Dim b As Button = DirectCast(sender, Button)

		Select Case b.Name
			Case "Button1"
				NewForm("THIS IS FORM 2", "C:\Users\lesha\Desktop\ABS.jpg")
			Case "Button2"
				NewForm("THIS IS FORM 3", "C:\Users\lesha\Desktop\PIC2.jpg")
		End Select
	End Sub
	Sub NewForm(s As String, img As String)
		With nf
			.Text = s
			.Dock = DockStyle.Fill
			.TopLevel = False
			.Parent = Panel1
			.TextBox1.Text = s
			.PictureBox1.BackgroundImage = Image.FromFile(img)
			.Show()
		End With
	End Sub
	Private Sub Button3_Click(sender As Object, e As EventArgs) Handles Button3.Click
		nf.TextBox1.Text = "Changed by Button 3"
	End Sub
	Private Sub Button4_Click(sender As Object, e As EventArgs) Handles Button4.Click
		nf.TextBox1.Text = "Changed by Button 4"
	End Sub
End Class

José Carlos 886 Reputation points

2023-10-08T19:37:35.35+00:00

Ok.

I will study your solution and try to adapt it in my program.

As soon as I have a solution, I'll post it here in the comments.

Thank you very much for now.
José Carlos 886 Reputation points

2023-10-08T21:50:36.0433333+00:00

I really can't do it. I will put an image of the screen and explain the objective.

When I click on Operações sobre Pastas, above the main form, the FormPasta form is loaded within a panel on the formPrincipal, which is this blue form. In this loaded form, there are 2 textBoxes and two disabled labels. Because it will depend on which ones will be enabled according to the buttons on the left.

The buttons are inside a panel on formPrincipal.

If I click the Criar button, I need the first textBox and the label next to the textbox, with the blue folder image, to be enabled. That's where I'm not succeeding.
Anonymous

2023-10-08T22:25:19.43+00:00

Hi

Post the code that is executed when the Criar button is clicked.

José Carlos 886

Dim nfp As New FormPastas             
With nfp                 
  .txtOrigem.Enabled = True                 
  .PicOrigem.Enabled = True                 
  .txtOrigem.Select()             
End With

FormPastas is the loaded form (in blue on the screen)

Anonymous

2023-10-09T11:03:28.4266667+00:00

Hi

Is ALL that inside the ButtonClick event handler? What I am trying to ascertain is where is the line Dim nfp As New FormPastas is it also in the ClickEvent (it needs to be declared at Class level)

José Carlos 886

Yes Les.

Inside the button's click event there is only this code.

Dim nfp As New FormPastas
With nfp                    
   .txtOrigem.Enabled = True                    
   .PicOrigem.Enabled = True                    
   .txtOrigem.Select()              
End With

Anonymous

2023-10-09T12:11:53.5466667+00:00
Hi

Well, now I am at a loss. If, as you say, the Form is already shown in the Panel, how did it get there - do you have localized versions of the Form in multiple places?

Depending on other things, you might need to define the 'nfp' as a variable at Class level so that references are applying to the same Form.

Without seeing the entire code, I would suggest:

Put a statement at Class level for 'nfp' i.e.

Public Class Form1 Dim nfp As New FormPastas Private Sub Form1_Load(sender ................

and comment out ALL other Declarations - such as the one in your ButtonClick event Handler. Then try to compile. Fix any exceptions thrown and see what happens.

The way you show means you are declaring another version of FormPastas, not even showing it, but then trying to refer to the ORIGINAL FormPastas that you say is already shown. This can not work as when you then try to access any Control on the OLD FormPastas, you are actually referring to Controls on the NEW FormPastas.

Hopefully that makes sense to you.

As a general question: why are you using Forms in the Panel instead of just adding Controls to the Panel and manipulating the data of those? If you check the code I posted, you will see that all I am doing is adding ONE version of the new Form in the Panel and from there, I just alter the data shown as needed.

I suspect that you really do not need to deal with other complexities arising from using new Forms in the Panel.
José Carlos 886 Reputation points

2023-10-09T12:34:43.2533333+00:00

Hi

I call the form by clicking on the Operações sobre Pastas link above. See image.

Once loaded I need to release the TextBox and the Label when I click on the Criar button.
Anonymous

2023-10-09T12:43:48.66+00:00

Hi

Sorry, but that makes no sense to me. Are you trying with any of the suggestions I made?
José Carlos 886 Reputation points

2023-10-09T12:49:14.2666667+00:00

OK.

I will follow your suggestion.

As soon as I have a solution I will let you know.

In reality, I wanted to learn different things.

It is not a professional application. It is a homemade application and a learning experience.

As soon as I have time, I will make the changes you suggested.

Thank you very much.

I'll comment again when I'm ready.
José Carlos 886 Reputation points

2023-10-09T13:20:40.77+00:00

Hi Les

I opened a new project and I'm doing it as per your suggestion.

It worked out.

I will adapt your solution.

Thank you very much.
José Carlos 886 Reputation points

2023-10-09T13:30:49.2666667+00:00

I can't find the button to accept your answer. Only from friend KO.
Anonymous

2023-10-09T14:06:22.3166667+00:00

Hi

I am glad it worked out. I have only been adding as Comment so no Answer.

Also, I would add, I think you may be developing a project by adding Forms to another Control as very much overkill and would suggest you choose another approach.
José Carlos 886 Reputation points

2023-10-09T14:11:33.5466667+00:00

Ok.

Very thanks.
José Carlos 886 Reputation points

2023-10-09T23:52:22.9233333+00:00

Hi Les.

I managed to adapt your suggestion into my program. All that was missing was Sub Newform. Everything worked. I got what I wanted.

Thank you again.
Anonymous

2023-10-10T00:30:11.2433333+00:00

Hi

Very good news. Good luck with developing further.

Answer accepted by question author

0 additional answers

Your answer

Anonymous

2023-10-08T15:26:52.45+00:00

Hi

Here is an example of opening a second Form with control properties changed (.Text, .BackgroundImage) from the first Form.

Option Strict On Option Explicit On Public Class Form1 Dim nf2 As New Form2 ' define an image just to show in nf2 Dim TestImage As Image = Image.FromFile("C:\Users\lesha\Desktop\ABS.jpg") Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click With nf2 .PictureBox1.BackgroundImage = TestImage ' set some example text in TextBox on nf2 .TextBox1.Text = "First Open" .Show() End With End Sub End Class
José Carlos 886 Reputation points

2023-10-08T16:49:22.4533333+00:00

Your example worked perfectly in a new project. In my project, it didn't work. When I click on the button to activate the controls on form2, form2 is already loaded on the screen within a panel on form1.

I used the same technique you showed me. There is no error, but the controls are not being activated.

Would the fact of loading form2 inside a Panel in form1 be the problem?

Tks
Anonymous

2023-10-08T18:50:48.5133333+00:00

Hi

Ah, you are putting it into a Panel on Main Form.

Give this example a try and see if it helps. This example uses 2 random images and Buttons 1 & 2 swap the Form in the Panel and Buttons 3 & 4 set the Text in the TextBox of whichever Form is in the Panel.

The Project has a second Form named Form2 which has the TextBox1 and PictureBox1 on it via the Designer with their various properties set as needed.

' 2 random images used Option Strict On Option Explicit On Public Class Form1 Dim nf As New Form2 Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load Text = "THIS IS FORM1" End Sub Private Sub Button_Click(sender As Object, e As EventArgs) Handles Button1.Click, Button2.Click Panel1.Controls.Clear() Dim b As Button = DirectCast(sender, Button) Select Case b.Name Case "Button1" NewForm("THIS IS FORM 2", "C:\Users\lesha\Desktop\ABS.jpg") Case "Button2" NewForm("THIS IS FORM 3", "C:\Users\lesha\Desktop\PIC2.jpg") End Select End Sub Sub NewForm(s As String, img As String) With nf .Text = s .Dock = DockStyle.Fill .TopLevel = False .Parent = Panel1 .TextBox1.Text = s .PictureBox1.BackgroundImage = Image.FromFile(img) .Show() End With End Sub Private Sub Button3_Click(sender As Object, e As EventArgs) Handles Button3.Click nf.TextBox1.Text = "Changed by Button 3" End Sub Private Sub Button4_Click(sender As Object, e As EventArgs) Handles Button4.Click nf.TextBox1.Text = "Changed by Button 4" End Sub End Class
José Carlos 886 Reputation points

2023-10-08T19:37:35.35+00:00

Ok.

I will study your solution and try to adapt it in my program.

As soon as I have a solution, I'll post it here in the comments.

Thank you very much for now.
José Carlos 886 Reputation points

2023-10-08T21:50:36.0433333+00:00

I really can't do it. I will put an image of the screen and explain the objective.

When I click on Operações sobre Pastas, above the main form, the FormPasta form is loaded within a panel on the formPrincipal, which is this blue form. In this loaded form, there are 2 textBoxes and two disabled labels. Because it will depend on which ones will be enabled according to the buttons on the left.

The buttons are inside a panel on formPrincipal.

If I click the Criar button, I need the first textBox and the label next to the textbox, with the blue folder image, to be enabled. That's where I'm not succeeding.
Anonymous

2023-10-08T22:25:19.43+00:00

Hi

Post the code that is executed when the Criar button is clicked.
José Carlos 886 Reputation points

2023-10-08T22:28:01.4133333+00:00

Dim nfp As New FormPastas With nfp .txtOrigem.Enabled = True .PicOrigem.Enabled = True .txtOrigem.Select() End With FormPastas is the loaded form (in blue on the screen)
Anonymous

2023-10-09T11:03:28.4266667+00:00

Hi

Is ALL that inside the ButtonClick event handler? What I am trying to ascertain is where is the line Dim nfp As New FormPastas is it also in the ClickEvent (it needs to be declared at Class level)
José Carlos 886 Reputation points

2023-10-09T11:12:27.99+00:00

Yes Les.

Inside the button's click event there is only this code.

Dim nfp As New FormPastas With nfp .txtOrigem.Enabled = True .PicOrigem.Enabled = True .txtOrigem.Select() End With
Anonymous

2023-10-09T12:11:53.5466667+00:00

Hi

Well, now I am at a loss. If, as you say, the Form is already shown in the Panel, how did it get there - do you have localized versions of the Form in multiple places?

Depending on other things, you might need to define the 'nfp' as a variable at Class level so that references are applying to the same Form.

Without seeing the entire code, I would suggest:

Put a statement at Class level for 'nfp' i.e.

Public Class Form1 Dim nfp As New FormPastas Private Sub Form1_Load(sender ................

and comment out ALL other Declarations - such as the one in your ButtonClick event Handler. Then try to compile. Fix any exceptions thrown and see what happens.

The way you show means you are declaring another version of FormPastas, not even showing it, but then trying to refer to the ORIGINAL FormPastas that you say is already shown. This can not work as when you then try to access any Control on the OLD FormPastas, you are actually referring to Controls on the NEW FormPastas.

Hopefully that makes sense to you.

As a general question: why are you using Forms in the Panel instead of just adding Controls to the Panel and manipulating the data of those? If you check the code I posted, you will see that all I am doing is adding ONE version of the new Form in the Panel and from there, I just alter the data shown as needed.

I suspect that you really do not need to deal with other complexities arising from using new Forms in the Panel.
José Carlos 886 Reputation points

2023-10-09T12:34:43.2533333+00:00

Hi

I call the form by clicking on the Operações sobre Pastas link above. See image.

Once loaded I need to release the TextBox and the Label when I click on the Criar button.
Anonymous

2023-10-09T12:43:48.66+00:00

Hi

Sorry, but that makes no sense to me. Are you trying with any of the suggestions I made?
José Carlos 886 Reputation points

2023-10-09T12:49:14.2666667+00:00

OK.

I will follow your suggestion.

As soon as I have a solution I will let you know.

In reality, I wanted to learn different things.

It is not a professional application. It is a homemade application and a learning experience.

As soon as I have time, I will make the changes you suggested.

Thank you very much.

I'll comment again when I'm ready.
José Carlos 886 Reputation points

2023-10-09T13:20:40.77+00:00

Hi Les

I opened a new project and I'm doing it as per your suggestion.

It worked out.

I will adapt your solution.

Thank you very much.
José Carlos 886 Reputation points

2023-10-09T13:30:49.2666667+00:00

I can't find the button to accept your answer. Only from friend KO.
Anonymous

2023-10-09T14:06:22.3166667+00:00

Hi

I am glad it worked out. I have only been adding as Comment so no Answer.

Also, I would add, I think you may be developing a project by adding Forms to another Control as very much overkill and would suggest you choose another approach.
José Carlos 886 Reputation points

2023-10-09T14:11:33.5466667+00:00

Ok.

Very thanks.
José Carlos 886 Reputation points

2023-10-09T23:52:22.9233333+00:00

Hi Les.

I managed to adapt your suggestion into my program. All that was missing was Sub Newform. Everything worked. I got what I wanted.

Thank you again.
Anonymous

2023-10-10T00:30:11.2433333+00:00

Hi

Very good news. Good luck with developing further.

Answer 1

KOZ6.0 6,735

Is this what you want to do?

Public Class MainForm

    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        Dim f As New SubForm()
        'Required
        f.TopLevel = False

        'if necessary
        f.Dock = DockStyle.Fill
        f.Text = String.Empty
        f.ControlBox = False

        ' Add form to panel
        FillPanel.Controls.Add(f)
        f.Show()
        f.TextBox1.Focus()
    End Sub

End Class

José Carlos 886 Reputation points

2023-10-08T18:07:16.27+00:00

Hi KO

Yes. I call form2 like that.

After form2 is loaded, I need to click on a button that is on form1 and activate 2 textboxes and 2 pictureboxes that are on form2.

I'm not able to activate these controls on form2 by clicking on the button on form1.

Did you understand?

José Carlos 886

I'm doing it like this when clicking the button:
             Dim nfp As New Form2
             With nfp
                 .txtOrigem.Enabled = True
                 .PicOrigem.Enabled = True
                 .txtOrigem.Select()
             End With

KOZ6.0 6,735

Probably the scope of the variable nfp is wrong. That must be make a field variable.

Public Class Form1

    Private nfp As New Form2()  ' Here

    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        nfp.TopLevel = False
        nfp.Dock = DockStyle.Fill
        nfp.Text = String.Empty
        nfp.ControlBox = False
        FillPanel.Controls.Add(nfp)
        nfp.Show()
        nfp.txtOrigem.Focus()
    End Sub

    Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
        With nfp
            .txtOrigem.Enabled = True
            .PicOrigem.Enabled = True
            .txtOrigem.Select()
        End With
    End Sub

End Class

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How to change controls from another form in visual basic

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