I have two buttons Start button and Stop button .I run my program by clicking on start button. I want to stop the program during the start button . But the program will not responde until the start buttun finish its job. How i can do check the stop buttun during the start. i heard about threading but i do not know how i can do it.
Private Sub Button_Start (ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
//my code
//check always if the user push stop if no continue if yes go to this sub
//my code
end sub
Private Sub Button_Stop (ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
stopClick = True
Dim Response As Integer
Response = MessageBox.Show("Do you really want to exit?", "", MessageBoxButtons.YesNo, MessageBoxIcon.Question)
If Response = vbYes Then
Me.Close()
End If
End Sub
you can use threading put button1 code in a function and use the thread .
you can refer to this example
'Thread created to handle the Background process for start_function
Dim t As System.Threading.Thread
Private Sub start_function()
While True
'your code here for Eg:
Dim i As Integer
i = i + 1
End While
End Sub
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
t = New System.Threading.Thread(AddressOf Me.start_function)
t.Start()
End Sub
Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
t.Abort()
End Sub
Drag a backgroundworker component onto your form.
Imports System.ComponentModel
Public Class Form1
Private Sub btnStart_Click(sender As Object, e As EventArgs) Handles btnStart.Click
Me.Text = "Busy Doing Work"
BackgroundWorker1.WorkerSupportsCancellation = True
BackgroundWorker1.RunWorkerAsync()
End Sub
Private Sub btnStop_Click(sender As Object, e As EventArgs) Handles btnStop.Click
Me.Text = "Asking to Cancel"
BackgroundWorker1.CancelAsync()
End Sub
Private Sub BackgroundWorker1_DoWork(sender As Object, e As System.ComponentModel.DoWorkEventArgs) Handles BackgroundWorker1.DoWork
While Not BackgroundWorker1.CancellationPending
System.Threading.Thread.Sleep(1000)
End While
End Sub
Private Sub BackgroundWorker1_RunWorkerCompleted(sender As Object, e As System.ComponentModel.RunWorkerCompletedEventArgs) Handles BackgroundWorker1.RunWorkerCompleted
Me.Text = "Cancelled"
End Sub
End Class
Related
So i have a form as below:
Public Class IPADSOFT
Private Sub Button6_Click(sender As Object, e As EventArgs) Handles Button6.Click
IPADSOFTTS.Show()
End Sub
Private Sub Button8_Click(sender As Object, e As EventArgs) Handles Button8.Click
Me.Hide()
End Sub
Private Sub Button7_Click(sender As Object, e As EventArgs) Handles Button7.Click
HOME.Show()
Me.Hide()
End Sub
End Class
which has 3 checkboxes labeled IPADSOFTBOX1, IPADSOFTBOX2, IPADSOFTBOX3
So... i have another form as follows:
Public Class IPADSOFTTS
Private Sub onload()
If IPADSOFT.IPADSOFTBOX1.Checked Then
Button1.Visible = True
Button3.Visible = True
Button5.Visible = True
End If
End Sub
Private Sub Button8_Click(sender As Object, e As EventArgs) Handles Button8.Click
Me.Hide()
End Sub
Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
End Sub
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
End Sub
Private Sub Button7_Click(sender As Object, e As EventArgs) Handles Button7.Click
HOME.Show()
IPADSOFT.Hide()
Me.Hide()
End Sub
End Class
Now the idea is that all the buttons on that second form are set to visible-false and i want the page to check which checkboxes are checked on the last form and then make the required buttons on this form visible... but it isnt working
What am i doing wrong?? i apologise im very very new to vb.net
Open the second form with this
Dim newForm As New IPADSOFTTS With
{.MainForm = Me}
newForm .Show()
Set Public MainForm As IPADSOFT below the Public Class of second form
Then use in the Load event
if MainForm.IPADSOFTBOX1.Checked = true then
'Do whatever
End if
How can i make this code to loop urls continuously in Webbrowser1, after run trough these links one time.
This is the code i have so far, but when i run this, the Webbrowser stop with last url, wich is google.com. What i want to do is when the last url is reached i want it to start from top again, and run trough links again and again, until i exit the program.
Public Class Form1
Private WithEvents backgroundWorker1 As System.ComponentModel.BackgroundWorker
Dim l As New List(Of String)
Dim flagDC As Boolean = False
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Button1.Hide()
Button3.Show()
l = New List(Of String)
l.Add("http://bbc.com/sipeu/php/zq.php")
l.Add("http://google.com")
l.Add("http://DCWC.com/sipeu/us.php")
l.Add("http://google.com")
l.Add("http://example.com/sipeu/v.php")
l.Add("http://google.com")
backgroundWorker1 = New System.ComponentModel.BackgroundWorker
backgroundWorker1.RunWorkerAsync()
End Sub
Private Sub BackgroundWorker2_DoWork(ByVal sender As System.Object,
ByVal e As System.ComponentModel.DoWorkEventArgs) _
Handles backgroundWorker1.DoWork
For Each www In l
flagDC = False
WebBrowser1.Navigate(www)
Do
Loop While Not flagDC
Next
End Sub
Private Sub WebBrowser1_DocumentCompleted(ByVal sender As System.Object,
ByVal e As System.Windows.Forms.WebBrowserDocumentCompletedEventArgs) _
Handles WebBrowser1.DocumentCompleted
System.Threading.Thread.Sleep(1000)
flagDC = True
End Sub
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
Button3.Hide()
ChangeUserAgent("troll001_v2-agent34")
WebBrowser1.Navigate("http://example.com/welcome.php")
End Sub
Private Sub Button3_Click(sender As Object, e As EventArgs) Handles Button3.Click
Close()
End Sub
Private Sub Button2_Click(sender As Object, e As EventArgs)
End Sub
I use the below code to verify if the text into a TextBox was changed and ask for saving changes:
Private TBoxTxtBefore As String = String.Empty
Private Sub TextBox1_Enter(ByVal sender As Object, ByVal e As System.EventArgs) Handles TextBox1.Enter
Try
TBoxTxtBefore = CType(sender, TextBox).Text
Catch ex As Exception
MsgBox(ex.ToString)
End Try
End Sub
Private Sub TextBox1_Leave(ByVal sender As Object, ByVal e As System.EventArgs) Handles TextBox1.Leave
Try
If CType(sender, TextBox).Text <> TBoxTxtBefore Then
Dim SN As MsgBoxResult = MsgBox("Save changes?", vbYesNo, "Save Changes")
If SN = vbYes Then Btn_SaveChanges.PerformClick()
End If
Catch ex As Exception
MsgBox(ex.ToString)
End Try
End Sub
But when I click a button (for example button1) while the cursor is inside TextBox1, only TextBox1.Leave event was raised.
How can I have Button?.click event raise after TextBox1.Leave event?
How can I have button1.click event raise after TextBox1.Leave event?
If TextBox1 has the focus and you click a button the leave event will fire before the click event. To test click in Texbox1, then click Button1.
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Debug.WriteLine("B1C")
End Sub
Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
Debug.WriteLine("B2C")
End Sub
Private Sub TextBox1_Leave(sender As Object, e As EventArgs) Handles TextBox1.Leave
Debug.WriteLine("TBL")
Button2.PerformClick()
End Sub
Try to clarify your question please.
edit: This recreates the problem I think you are having,
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Debug.WriteLine("B1C")
End Sub
Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
Debug.WriteLine("B2C")
End Sub
Private Sub TextBox1_Leave(sender As Object, e As EventArgs) Handles TextBox1.Leave
MessageBox.Show("FOO")
Debug.WriteLine("TBL")
Button2.PerformClick()
End Sub
Did some searching and found that the Message box causes pending focus events to be lost.
Thanks to dbasnett's hints I was able to get the name of the control that fired the Leave event, so to call it (if it's a button) after the Message Box was showed:
Private Sub TextBox1_Leave(ByVal sender As Object, ByVal e As System.EventArgs) Handles TextBox1.Leave
Try
Dim FiringCtrl As Control = Me.Activecontrol
If CType(sender, TextBox).Text <> TBoxTxtBefore _
AndAlso FiringCtrl.Name <> "Btn_SaveChanges" Then
Dim SN As MsgBoxResult = MsgBox("Save changes?", vbYesNo, "Save Changes")
If SN = vbYes Then Btn_SaveChanges.PerformClick()
If TypeOf FiringCtrl Is Button Then
DirectCast(FiringCtrl, Button).PerformClick()
End If
End If
Catch ex As Exception
MsgBox(ex.ToString)
End Try
End Sub
Anyway Plutonix showed me a better solution here
You can call multiple events one after the another. Your TextBox1_Leave event could trigger Button1_click event.
Private Sub TextBox1_Leave(ByVal sender As Object, ByVal e As System.EventArgs) Handles TextBox1.Leave
'Take the control to another sub. Pass the sender control and the event details as arguments
Call Button1_Click(sender,e)
End Sub
Private Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click
'Do your stuff here
End Sub
Hope this helps.
I have a problem with my code. I keep getting Multiple thread Error with backgroundworker, because of the combobox item display. Please look at my code below its a very simple code which I am planning to use on big scale, all I want it to do is "If item "1" selected show item "1" in label1. I can only assume that problem exists because Combobox runs in different thread....
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
BackgroundWorker1.runworkerasync()
BackgroundWorker1.WorkerReportsProgress = True
Me.Cursor = Cursors.WaitCursor 'Cursor changes to wait
End Sub
Public Structure controlwithtext
Public controlname As Control
Public text As String
Public Sub New(ByVal ctrl As Control, ByVal text As String)
Me.controlname = ctrl
Me.text = text
End Sub
End Structure
Private Sub BackgroundWorker1_DoWork(ByVal sender As System.Object, ByVal e As DoWorkEventArgs) Handles BackgroundWorker1.DoWork
If comboBox1.SelectedItem = "1" then
BackgroundWorker1.ReportProgress(5, New controlwithtext(Label1, ComboBox1.SelectedItem))
End If
End Sub
Private Sub SetBackgroundWorker_ProgressChanged(ByVal sender As Object,
ByVal e As ProgressChangedEventArgs) Handles BackgroundWorker1.ProgressChanged
If TypeOf e.UserState Is controlwithtext Then
Dim cwt As controlwithtext = CType(e.UserState, controlwithtext)
cwt.controlname.Text = cwt.text
End If
End Sub
Here's an example of how to read from and write to controls from the BackgroundWorker thread:
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
BackgroundWorker1.RunWorkerAsync()
End Sub
Private Sub BackgroundWorker1_DoWork(sender As Object, e As DoWorkEventArgs) Handles BackgroundWorker1.DoWork
While True
System.Threading.Thread.Sleep(250)
Dim selection As String = Me.Invoke(Function()
If Not IsNothing(ComboBox1.SelectedItem) Then
Return ComboBox1.SelectedItem.ToString
Else
Return String.Empty
End If
End Function).ToString
If selection = "1" Then
Me.Invoke(Sub()
Label1.Text = ComboBox1.SelectedItem.ToString
End Sub)
Else
Me.Invoke(Sub()
Label1.Text = "something else"
End Sub)
End If
End While
End Sub
I'm looking for a way to detect if the user has been idle for 5 min then do something, and if and when he comes back that thing will stop, for example a timer.
This is what i have tried (but this will only detect if form1 has been inactive / not clicked or anything):
Public Class Form1
Private Sub form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
'You should have already set the interval in the designer...
Timer1.Start()
End Sub
Private Sub form1_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles Me.KeyPress
Timer1.Stop()
Timer1.Start()
End Sub
Private Sub form1_MouseMove(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles Me.MouseMove
Timer1.Stop()
Timer1.Start()
End Sub
Private Sub form1_MouseClick(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles Me.MouseClick
Timer1.Stop()
Timer1.Start()
End Sub
Private Sub Timer_Tick(ByVal sender As Object, ByVal e As System.EventArgs) Handles Timer1.Tick
MsgBox("Been idle for to long") 'I just have the program exiting, though you could have it do whatever you want.
End Sub
End Class
This is done easiest by implementing the IMessageFilter interface in your main form. It lets you sniff at input messages before they are dispatched. Restart a timer when you see the user operating the mouse or keyboard.
Drop a timer on the main form and set the Interval property to the timeout. Start with 2000 so you can see it work. Then make the code in your main form look like this:
Public Class Form1
Implements IMessageFilter
Public Sub New()
InitializeComponent()
Application.AddMessageFilter(Me)
Timer1.Enabled = True
End Sub
Public Function PreFilterMessage(ByRef m As Message) As Boolean Implements IMessageFilter.PreFilterMessage
'' Retrigger timer on keyboard and mouse messages
If (m.Msg >= &H100 And m.Msg <= &H109) Or (m.Msg >= &H200 And m.Msg <= &H20E) Then
Timer1.Stop()
Timer1.Start()
End If
End Function
Private Sub Timer1_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Timer1.Tick
Timer1.Stop()
MessageBox.Show("Time is up!")
End Sub
End Class
You may have to add code that disables the timer temporarily if you display any modal dialogs that are not implemented in .NET code.
This might work by setting it to just call the Reset idk i just want it work all over the program idk how to do it, i just created this code :
Public Class test
Dim IdleTimer As String
Dim testsave As String
Dim idle_TimerSet As String = 60 '<---- Here You choose The timer (1 per Sec)
Private Sub test_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
IdleTimer = idle_TimerSet
End Sub
Private Sub Idle_Tick(sender As Object, e As EventArgs) Handles Idle.Tick
If IdleTimer <= 1 Then
MsgBox("[ Idle Screen ]")
Else
IdleTimer = IdleTimer - 1 '<--- The Counter
IdleTracker.Text = IdleTimer
End If
End Sub
Private Sub test_MouseDown(sender As Object, e As MouseEventArgs) Handles Me.MouseDown
Call Reset_Idle() 'This is on the main Form
End Sub
Private Sub test_MouseMove(sender As Object, e As MouseEventArgs) Handles Me.MouseMove
Call Reset_Idle() 'This is on the main Form
End Sub
Public Sub Reset_Idle() '<-- The Reset Action
'Idle.Enabled = False
IdleTimer = idle_TimerSet
'Idle.Enabled = True
End Sub
End Class