I'm learning for vb.net step by step. I have two forms and I would like to make a code that is, when I click Button1 which is in the other form, then my main sub exit. I have already searched in google, but I didn't find anything. How can I solve that line?
Public Class Form1
Public Sub Main()
Form2.ShowDialog()
If Form2.Button1_Click = True then '**This line is what I stucked**
Exit Sub
End if
End Sub
End Class
Public Class Form2
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Me.Close()
End Sub
End Class
An example using DialogResult.
In Form1:
If Form2.ShowDialog = DialogResult.OK Then
' ... do something in here ...
End If
In Form2:
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Me.DialogResult = DialogResult.OK
End Sub
Note that if the user cancels the Form2 dialog without hitting the button then you'll get a result of Cancel back instead.
Related
I am a volunteer for the National Park Service trying to convert an interactive display originally created 20 years ago in a language called ToolBook into Visual Basic. The program consists of several projects under a single solution. The starting project, called "MainMenu", can be thought of as a library, with buttons that bring up “books.” The project called Geology is an example “book” and GeologyMenu can be thought of as the index of a book. The buttons on GeologyMenu connect to “chapters” that explain and show examples of geologic processes in the park. The “chapters” are within the project “Geology” and work fine within the project. All forms used in the program have timers that allow the program to re-set itself to MainMenu when not in use.
In a previous post, with the help of Idle Mind (thank you again), the following code for works fine for going from MainMenu to GeologyMenu and in the reverse direction as long as no button is pushed on GeologyMenu. However, if I go to a “chapter” I can no longer get back to the MainMenu from the GeologyMenu. Here is the relevant code:
MainMenu
Public Class frmMainMenu
Private Sub BtnGeology_Click(sender As Object, e As EventArgs) Handles btnGeology.Click
Dim formNew As New Geology.frmGeologyMenu
AddHandler formNew.FormClosed, AddressOf formNew_FormClosed
TimerMain.Stop()
formNew.Show()
Me.Hide()
End Sub
Private Sub formNew_FormClosed(Sender As Object, e As FormClosedEventArgs)
lblTime.Text = 8
TimerMain.Start()
Me.Show()
End Sub
GeologyMenu
Public Class frmGeologyMenu
Public Sub frmGeologyMenu_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
lblTime.Text = 6
TimerGeologyMenu.Enabled = True
Me.Show()
End Sub
Private Sub BtnErosion_Click(sender As Object, e As EventArgs) Handles btnErosion.Click
TimerGeologyMenu.Stop()
frmErosionP01.Show()
Me.Hide()
End Sub
The code below for takes the viewer to the Erosion “chapter”
Private Sub BtnErosion_Click(sender As Object, e As EventArgs) Handles btnErosion.Click
TimerGeologyMenu.Stop()
frmErosionP01.Show()
Me.Hide()
End Sub
Erosion “Chapter” . This is the code for the button on every form in Erosion that takes the program back to GeologyMenu
Public Class frmErosionP02
Private Sub BtnGeologyMenu_Click(sender As Object, e As EventArgs) Handles btnGeologyMenu.Click
My.Computer.Audio.Stop()
frmGeologyMenu.lblTime.Text = 10
frmGeologyMenu.TimerGeologyMenu.Enabled = True
frmGeologyMenu.Show()
Me.Close()
End Sub
The code for forms within Erosion takes me back to GeologyMenu, but then MainMenu won’t show when I close GeologyMenu and I don’t understand why or how to fix it. Thank you in advance for your help!
Simply, pass the previous menu/Form to the new one in a parameterized constructor and keep it in a class variable, then handle the Form.Closed event of the new menu to show the previous one.
Example for the relevant code:
Public Class frmMainMenu
Inherits Form
Private Sub BtnGeology_Click(sender As Object, e As EventArgs) Handles btnGeology.Click
Dim formNew As New frmGeologyMenu(Me)
Me.Hide()
formNew.Show()
End Sub
End Class
Public Class frmGeologyMenu
Inherits Form
Private PreviousMenu As Form
Private Sub New()
InitializeComponent()
'...
End Sub
Sub New(prevMenu As Form)
Me.New()
PreviousMenu = prevMenu
AddHandler FormClosed,
Sub(s, e)
PreviousMenu.Show()
End Sub
End Sub
Private Sub BtnErosion_Click(sender As Object, e As EventArgs) Handles btnErosion.Click
Dim frmErosion As New frmErosionP02(Me)
Me.Hide()
frmErosion.Show()
End Sub
End Class
Public Class frmErosionP02
Inherits Form
Private PreviousMenu As Form
Private Sub New()
InitializeComponent()
'...
End Sub
Public Sub New(prevMenu As Form)
Me.New()
PreviousMenu = prevMenu
AddHandler FormClosed,
Sub(s, e)
PreviousMenu.Show()
End Sub
End Sub
End Class
This is pretty rudimentary, but I can't figure it out.
I want to programmatically close form1 when form2 closes, if form1 is still open. Form2 was opened by a command button on form1.
The code on Form1 that opens Form2 is:
Dim frm As New form2
frm.Show()
What's the best way when Form2 closes to close any open copies of Form1 that are open, also?
If you want to handle your two forms independently, you need to watch over them from a third form or class. So my suggestion would be to create both of them in this third class, and pass a reference of the second form to the first form so it can then open it. This way:
Public Class MyHelper
Public Sub CreateForms()
Dim form2 as New Form2()
AddHandler form2.Closed, AddressOf Form2_OnClosed
‘ Create as many copies as you need
Dim form1 as New Form1(form2)
form1.Show()
End Sub
Protected Sub Form2_OnClosed(sender as object, e as EventArgs)
‘ Same code for each form1 that has been created and opened.
If (form1.IsOpen) Then form1.Close()
End Sub
End Class
Public Class Form1
Private _form2 as Form2
Public Property IsOpen as Boolean = false
Public Sub New(form2 as Form2)
_form2 = form2
End Sub
Protected Sub MyButton_Click(sender as object, e as EventArgs) handles MyButton.Click
‘ You open your form here or wherever you want (even on the constructor)
_form2.Show()
End Sub
Protected Sub Me_OnClosed(sender as object, e as EventArgs) handles Me.Closed
Me.IsOpen = false
End Sub
Protected Sub Me_OnShown(sender as object, e as EventArgs) handles Me.Shown
Me.IsOpen = true
End Sub
End Class
Add this reference to make it work.
Imports System.Linq
If Application.OpenForms().OfType(Of Form1).Any Then
MsgBox("Form1 is open")
End If
Supposing you have 3 forms and want to close the other two on button click
Private Sub EMPLEADOToolStripMenuItem_Click(sender As Object, e As EventArgs) Handles EMPLEADOToolStripMenuItem.Click
If Application.OpenForms().OfType(Of BUSCAR_INDEX).Any Then
BUSCAR_INDEX.Close()
ElseIf Application.OpenForms().OfType(Of MIEMBROS_INDEX).Any Then
MIEMBROS_INDEX.Close()
End If
EMP_INDEX.Show()
EMP_INDEX.EmpIDTextBox.Text = EmpIDTextBox.Text
End Sub
My program was opening a different form to what I wanted it to. The answers solved it.
Basically I wanted to stop a form opening when the program started, but when it opened manually (on a button press), it updated the data. The second part of the problem has not been solved, but the first part has been.
You can try something like this:
Public Class HomeForm
Private WithEvents m_DataChangeForm As DataChangeForm
Private Sub HomeForm_Load(sender As Object, e As EventArgs) Handles MyBase.Load
m_DataChangeForm = New DataChangeForm()
m_DataChangeForm.Show()
End Sub
Private Sub OnDataSourceChanged(sender As Object, args As EventArgs) Handles m_DataChangeForm.OnDataSourceChanged
MessageBox.Show("Data source changed!")
End Sub
End Class
Public Class DataChangeForm
Inherits Form
Public Event OnDataSourceChanged(sender As Object, args As EventArgs)
Private WithEvents m_Button As Button
Public Sub New()
m_Button = New Button()
m_Button.Text = "Change"
m_Button.Parent = Me
End Sub
Public Sub buttonClick(sender As Object, args As EventArgs) Handles m_Button.Click
RaiseEvent OnDataSourceChanged(sender, args)
Me.Close()
End Sub
End Class
Reason your form is displayed before HomeForm is becaouse you call ShowDialog, it blocks until DataChangeForm is closed.
You should move your code from "Load" to "Shown" Event.
Private Sub Homefrm_Shown(sender As Object, e As EventArgs) Handles Me.Shown
Using fp = New dataChangefrm(m_database)
If fp.ShowDialog() = DialogResult.OK Then
uwgHome.DataSource = Nothing
loadData()
End If
End Using
Me.Location = New Point(0, 0)
loadData()
End Sub
Please have a look on the Handle in the first line. It depends on your Project.
I am just starting out with Visual basic .Net.
I can't seem to figure what's the scope of button properties like button.text. Can they be used outside the button_click event sub? And if so, how?
How can I modify button properties from a module in real time when a certain condition is met?
I'd surely appreciate some guidance and an example, if possible. Thanks.
Just as quick sample, I don't suggest doing something like this
I have 2 forms open, Form2 and Form3. Each form has a button on it.
I also have a Module, called MyModule
Public Class Form2
Public Sub ChangeButtonText(ByVal s As String)
Button1.Text = s
End Sub
End Class
.
Public Module MyModule
Sub ChangeForm2Btn()
Form2.ChangeButtonText("LOL")
End Sub
End Module
From my Form3 I click the button and call the module function to change Form2 button's text
Public Class Form3
Private Sub Form3_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
Form2.Show()
End Sub
Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
MyModule.ChangeForm2Btn()
End Sub
End Class
You could pass a reference to the button to a sub in the module, and then call that sub from the form.
i.e.
Public Class Form1
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
ChangeButtonText(Me.Button1, "Changed")
End Sub
End Class
Module modButton
Public Sub ChangeButtonText(ByRef Button As Button, ByVal Text As String)
Button.Text = Text
End Sub
End Module
So putting it as simply as possible, I have one class which opens a form from inside sub like so:
Public Sub LoadExtension()
'various code...
Dim form as new frmMain
frmMain.ShowDialog()
'various code...
End Sub
And inside this form I have two buttons, one will just close the form, so the LoadExtension() sub will continue. The other button I want to use to 'exit' the LoadExtension() sub inside the main class so that loading stops completely. The button event inside the form module is like so:
Private Sub btnStopLoad_click(sender as object, e as eventargs) handles btnStopLoad.click
'exit the LoadExtension sub somehow
End sub
What is the simplest way to achieve this? I thought I could do something like this in the LoadExtension() sub (after the .ShowDialog):
If frmMain.btnStopLoad.clicked then
Exit Sub
End If
But it won't let me do that from the class module, apparently I need to use 'raise event' or something? I'm not very familiar with the way that events work. Can someone offer me an easy solution? I'd be very grateful. I've been looking around the web for a solution but haven't had any success. Thanks for your time.
You can achieve this by setting the DialogResult of the frmMain.
Public Class frmMain
Inherits Form
Private Sub _ButtonContinueClick(sender As Object, e As EventArgs) Handles ButtonContinue.Click
Me.DialogResult = Windows.Forms.DialogResult.OK
Me.Close()
End Sub
Private Sub ButtonExitClick(sender As Object, e As EventArgs) Handles ButtonExit.Click
Me.DialogResult = Windows.Forms.DialogResult.Cancel
Me.Close()
End Sub
End Class
Then change the LoadExtension method to something like this:
Public Sub LoadExtension()
'various code...
Using form As New frmMain()
If (form.ShowDialog() <> Windows.Forms.DialogResult.OK) Then
Exit Sub
End If
End Using
'various code...
End Sub
The simplest way is to use dialogresult to let the LoadExtension function know which button was pressed.
DialogResult is what you are looking for - the standard way to do it.
You can, however, subscribe to events of another form's controls, like this:
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
Dim frm As New Form2
AddHandler frm.Button1.Click, AddressOf OtherFormButton_Click
frm.ShowDialog()
End Sub
Private Sub OtherFormButton_Click(sender As System.Object, e As System.EventArgs)
MessageBox.Show("hello")
End Sub
This is assuming Form2 has a button named Button1.