I'm struggling with the solution of passing the variables through different classes in VB.
The goal is to run a Form to present the progress and other info (I made a BackgroundWorker inside Form1), while a different vb thread is doing the job.
I finished with the MainClass and myWrapper, which does not do the job in the Form1 window. I set the class WorkerArgs between them, to pass the arguments, but I can only create 2 different objects of WorkerArgs.
I need to pass the same WorkerArgs.startProgress value to Form1 Class... How to do it?
Public Class MainClass
Shared Sub Main()
Dim form1 As Form = New Form1
Dim myWrapper As WorkerArgs = New WorkerArgs
form1.Show()
myWrapper.startProgress = "start"
End Sub
End Class
Public Class WorkerArgs
Public startProgress As String
Public passPercentage As String
End Class
Public Class Form1
Public Sub OnLoad(ByVal sender As Object, ByVal e As System.EventArgs) Handles MyBase.Load
Dim args As WorkerArgs
BackgroundWorker1.RunWorkerAsync(args)
End Sub
Public Sub bgw1_DoWork(ByVal sender As Object, ByVal e As DoWorkEventArgs) Handles BackgroundWorker1.DoWork
System.Threading.Thread.Sleep(1000)
' Access variables through e
Dim args As WorkerArgs = e.Argument
' Do something with args
Dim str As String = args.startProgress
If str = "start" Then
MessageBox.Show(str)
End If
End Sub
[...]
End Class
Related
I have three forms in total and i want to trigger one of the button on form 3 to be triggered automatically when form 1 loaded
Form 1
Public Class frmIOMain
' In This Form load I want to trigger the above mentioned button
Private Sub IOMain_Load(sender As Object, e As System.EventArgs) Handles Me.Load
' I want to Trigger the Above mentioned button here when my form is loaded
' But it is not working for me
frmUpdateDueDates.cmdUpdate_Click(Nothing, Nothing)
End Sub
End Class
Form 2
Public Class TestEquipmentManagement
Public EquipementTable As New DataTable("EquipmentTable")
Public EquiTypeSelection As String
Public EquiManufacturerSelection As String
Public EquiList_PK As New List(Of Integer)
Dim targetEquipmentList As New List(Of Model.equipment)
Private equipDB As Model.Entities = Nothing
Public Shared viewManager As ViewManager
Private equipment As New List(Of Model.equipment)
'Dim WithEvents excNewPFM As New VBACom
Public EquipCalTable As New DataTable("EquipCalTable")
Public Sub New()
Dim todayplusoneyear As Date
todayplusoneyear = Date.Today
todayplusoneyear = todayplusoneyear.AddYears(1)
'Assign current db
equipDB = frmIOMain.db
End Sub
End Class
Form 3
Public Class frmUpdateDueDates
Private EquipmentUpdates As UpdateCalibrationsViewModel
Private _success As Boolean = False
Public Sub New(db As Entities)
' Dieser Aufruf ist für den Designer erforderlich.
InitializeComponent()
EquipmentUpdates = New UpdateCalibrationsViewModel(db, New CAQ23(), False)
'Add Handlers
AddHandler EquipmentUpdates.OnProgressChanged, AddressOf progressChangedHandler
AddHandler EquipmentUpdates.OnInfotextChanged, AddressOf infoTextChangedHandler
prgUpdates.Maximum = EquipmentUpdates.intProgressMax
End Sub
Public Sub cmdUpdate_Click(sender As Object, e As EventArgs) Handles cmdUpdate.Click
cmdUpdate.Enabled = False
_success = EquipmentUpdates.startUpdating()
cmdCancel.Text = "Close"
End Sub
End Class
I want "cmdUpdate_Click" Button which is on form 3 to be triggered when my form 1 is loaded
Can Anyone tell me how i can do that?
Firstly, create an instance of the form, instead of using its default form instance. Calling a click handler across forms isn't a good idea. The handler may use the arguments sender As Object, e As EventArgs and from outside of the containing class, you can't assume you know that. Better practice would be to create a method which performs the click within the form, such as
Public Class frmUpdateDueDates
Public Sub cmdUpdateClick()
cmdUpdate.PerformClick()
End Sub
Private Sub cmdUpdate_Click(sender As Object, e As EventArgs) Handles cmdUpdate.Click
cmdUpdate.Enabled = False
_success = EquipmentUpdates.startUpdating()
cmdCancel.Text = "Close"
End Sub
End Class
Public Class frmIOMain
Private myFrmUpdateDueDates As frmUpdateDueDates
Private Sub IOMain_Load(sender As Object, e As System.EventArgs) Handles Me.Load
myFrmUpdateDueDates = New FrmUpdateDueDates()
myFrmUpdateDueDates.Show()
'myFrmUpdateDueDates.cmdUpdate_Click(Nothing, Nothing)
myFrmUpdateDueDates.cmdUpdateClick()
End Sub
End Class
And you can change the access modifier of the click handler back to Private
Even better would be to put the work into a different method which the click handler calls. Then the other form doesn't even need to know the button exists. Such as
Public Class frmUpdateDueDates
Public Sub DoUpdating()
cmdUpdate.Enabled = False
_success = EquipmentUpdates.startUpdating()
cmdCancel.Text = "Close"
End Sub
Private Sub cmdUpdate_Click(sender As Object, e As EventArgs) Handles cmdUpdate.Click
DoUpdating()
End Sub
End Class
Public Class frmIOMain
Private myFrmUpdateDueDates As frmUpdateDueDates
Private Sub IOMain_Load(sender As Object, e As System.EventArgs) Handles Me.Load
myFrmUpdateDueDates = New FrmUpdateDueDates()
myFrmUpdateDueDates.Show()
'myFrmUpdateDueDates.cmdUpdate_Click(Nothing, Nothing)
myFrmUpdateDueDates.DoUpdating()
End Sub
End Class
Have anyone idea why my code return "" inside my Textbox ? :-)
This i have in main Class
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button2.Click
Dim My_Thread as Threading.Thread
My_Thread = New Threading.Thread(AddressOf Module1.MyTest)
My_Thread.Start()
End Sub
And this in module1
Sub MyTest()
Dim TestingValue as string = "Test"
MainForm.Textbox1.Text = TestingValue
End sub
Invoke all time crash code and another try return "" inside texbox1 :-/
Create a Sub Class with public declarations to any object you want on MainForm, then pass the class as a parameter to the module. This would be a cleaner approach than passing the entire Form class instance. Then using the method that Jimi has suggested you can setyou textboxs without cross thread violation.
Public Class MainForm
Public Class PassToModule
Public TxBx1 As TextBox = MainForm.TextBox1
Public TxBx2 As TextBox = MainForm.TextBox2
End Class
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim PassToModule As New PassToModule
Dim My_Thread As Threading.Thread
My_Thread = New Threading.Thread(AddressOf MyTest)
My_Thread.Start(PassToModule)
End Sub
End Class
Module Module1
Dim FromMainForm As MainForm.PassToModule
Sub MyTest(PasToModule As MainForm.PassToModule)
FromMainForm = PasToModule
FromMainForm.TxBx1.BeginInvoke(New MethodInvoker(Sub()
FromMainForm.TxBx1.Text = "Test"
FromMainForm.TxBx2.Text = "Test"
End Sub))
End Sub
End Module
This question already has answers here:
Passing variables between windows forms in VS 2010
(3 answers)
How to pass value from Form1 to Form2
(2 answers)
Closed 5 years ago.
Is it possible to use a label? I'm planning to display a scoring system, like every correct answer the score will add 10pts.
Use an instance of a class within a form. The Form can call methods of the Class. The Class can raise events to the Form. Don't talk directly from a Class to a Form. Or from one Form to another.
Form1 with TextBox1:
Public Class Form1
Private myClass1 As Class1
Private myForm2 As Form2
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
myClass1 = New Class1()
myForm2 = New Form2(myClass1)
myForm2.Show()
End Sub
Private Sub TextBox1_TextChanged(sender As Object, e As EventArgs) Handles TextBox1.TextChanged
myClass1.SetText(TextBox1.Text)
End Sub
End Class
Form2 with Label1:
Public Class Form2
Private WithEvents myClass1 As Class1
Public Sub New(instance As Class1)
InitializeComponent()
myClass1 = instance
End Sub
Private Sub myClass1TextSet(value As String) Handles myClass1.TextSet
Me.Label1.Text = value
End Sub
End Class
Class1:
Public Class Class1
Private text As String = ""
Public Event TextSet(value As String)
Public Sub SetText(value As String)
Me.text = value
RaiseEvent TextSet(value)
End Sub
End Class
Form2.Label1 will update as you type in Form1.TextBox1. You may change it around as you need to fit your application, but try to keep this structure.
Form >> instance >> Class
Class >> events >> Form
The form instantiating the other form is for simplicity of this example. Larger scale projects could have a form loader factory responsible for making forms.
In your Form2 add a public shared integer
Public Shared score As Integer = 0
Private Sub Form2_Load(sender As Object, e As EventArgs) Handles MyBase.Load
End Sub
Then in Form1 increase it by adding to it
Form2.score += 50
for example
Add two forms to project
in Form2 define Label1 control
and in Form1
Public Class Form1
Private intScore As Integer = 0
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles Me.Load
Form2.Show()
End Sub
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Form2.Label1.Text = intScore.ToString
End Sub
End Class
I'm trying to pass form name and object as parameters of my public sub because I have 2 forms and they are almost identical to one another.
For example I have richtextbox1 in Form1 and I also have richtextbox1 in Form2, I would like to create a public sub something like this.
Public Sub Sub1(ByVal frm_name As form, Byval obj_name As object)
frm_name.obj_name.Lines.Length 'Get the length of lines of that richtextbox
End Sub
Then when I want to call it
'Form 1 Codes
Public Class Form1
Private Sub Tmr1_Tick(sender As Object, e As EventArgs) Handles Tmr1.Tick
Sub1(me, richtextbox1)
End Sub
End Class
'Form 2 Codes
Public Class Form2
Private Sub Tmr1_Tick(sender As Object, e As EventArgs) Handles Tmr1.Tick
Sub1(me, richtextbox1)
End Sub
End Class
It is not working the way I want it, is there anything I can do for it to work?
Think about it. You are saying that you're passing the names of things but you're not. You're not passing the name of a form; you're passing the form itself. You're not passing the name of an object; you're passing the object itself. What is the actual point of this? It's to get the number of lines in a RichTextBox, right? So, write a method that takes a RichTextBox as an argument and then call it passing a RichTextBox.
Public Sub Sub1(rtb As RichTextBox)
Dim lineCount = rtb.Lines.Length
'...
End Sub
'Form 1 Codes
Public Class Form1
Private Sub Tmr1_Tick(sender As Object, e As EventArgs) Handles Tmr1.Tick
Sub1(richtextbox1)
End Sub
End Class
'Form 2 Codes
Public Class Form2
Private Sub Tmr1_Tick(sender As Object, e As EventArgs) Handles Tmr1.Tick
Sub1(richtextbox1)
End Sub
End Class
Hi I get the error above when I ran this code. When I try to run a VBNet program that has 3 forms.
I'm just trying to pass list Items from one form to another, but I get an error before the program compiles.
Public Class frmCart
Dim frmComic As New comicBooks
Dim frmAudio As New audioBooks
Public decSubTotal As Decimal
Private Sub ShowToolStripMenuItem_Click(sender As Object, e As EventArgs) Handles ShowToolStripMenuItem.Click
frmComic.ShowDialog()
End Sub
Private Sub ShowDialogToolStripMenuItem_Click(sender As Object, e As EventArgs) Handles ShowDialogToolStripMenuItem.Click
frmAudio.ShowDialog()
End Sub
End Class
Now the frmComic is
Public Class comicBooks
Dim frmCartForm As New frmCart
Public decPrice1 As Decimal = 20.95D
Public decPrice2 As Decimal = 10.50D
Private Sub btnAdd_Click(sender As Object, e As EventArgs) Handles btnAdd.Click
Select Case lstComicBooks.SelectedItem
Case "Comic #1 (Print)"
frmCart.lstProductsSelected.Items.Add("Comic #1")
frmCart.decSubTotal += decPrice1
Case "The History of Scotland (Print)"
frmCart.lstProductsSelected.Items.Add("Comic #2")
frmCart.decSubTotal += decPrice2
Case Else
MessageBox.Show("Please select a Comic")
End Select
End Sub
End Class
I don't know why it's recursive if I call the Dialog only once.
Thanks
To avoid recursion, you should pass the current instance of frmCart into the comicBooks class in the constructor. Something like this:
Public Class frmCart
Dim frmComic As New comicBooks(Me) '<--- Pass current form into constructor
End Class
Public Class comicBooks
Dim frmCartForm As frmCart '<--- variable to hold passed in form instance
Public Sub New(cartForm As frmCart) '<--- Constructor to take instance of form
Me.frmCartForm = cartForm '<--- Assign passed in reference to our variable
End Sub
Private Sub btnAdd_Click(sender As Object, e As EventArgs) Handles btnAdd.Click
'Use frmCartForm here
End Sub
End Class
Class comicBooks instantiates a new frmCart.
frmCart instantiates a new comicBooks
Go back to 1
Remove the frmCartForm declaration in comicBooks