frmMain has a button that kicks off a background worker
Private Sub btnProcessITN_Click(sender As Object, e As EventArgs) Handles btnProcessITN.Click
Me.frmMainProgressBar.Visible = True
Me.btnProcessITN.Text = "working..." & Me.frmMainProgressBar.Value & "%"
Me.btnProcessITN.Enabled = False
backgroundWorker2.WorkerReportsProgress = True
BackgroundWorker2.RunWorkerAsync()
End Sub
Private Sub backgroundWorker2_DoWork(ByVal sender As Object, ByVal e As System.ComponentModel.DoWorkEventArgs) Handles BackgroundWorker2.DoWork
ProcessITN()
End Sub
ProcessITN lives in modITN. This runs, does its thing, then PROBLEM
Public Sub ProcessITN()
...doing work here....
frmMain.updateProgress(current, Max)
End Sub
and back in form main I have a function that tries to update the progress of the background worker, and update a progress bar on the form
Public Function updateProgress(current As Integer, Max As Integer) As Boolean
BackgroundWorker2.ReportProgress((current / Max) * 100)
Return True
End Function
Private Sub backgroundWorker2_ProgressChanged( _
ByVal sender As Object, ByVal e As System.ComponentModel.ProgressChangedEventArgs) _ Handles BackgroundWorker2.ProgressChanged
Me.frmMainProgressBar.Value = e.ProgressPercentage
Me.btnProcessITN.Text = "working..." & Me.frmMainProgressBar.Value & "%"
'Me.txtProgress.Text = Me.txtProgress.Text & vbNewLine & strMessage
Me.txtProgress.AppendText(vbNewLine & strMessage)
End Sub
Now, the problem is, that although the code is running, and the values are being passed across correctly from modITN to frmMain, the form itself is not refreshing. the progress bar does not change. txtProgress does not change.
N.B this code was working perfectly when the stuff within modITN was within frmMain. I moved it to try and tidy my code.
You may still have a look here, I had the same question - and there are some more issues to it.
Multithreading for a progressbar and code locations (vb.net)?
VB.net's 'Default Instance' of Forms is a hideous trap in my opinion.
I've sorted the problem!
I moved the backgroundworker blocks to modITN, out frmMain. The whole thing runs in modITN now, and updates the progress bar from there. frmMain simply calls the sub in modITN to start the whole thing off.
Simple!
Related
I'm trying to "enhance" my reporting code by adding a loading screen while the Crystal Report is being prepared/loaded. Before I started trying to add the loading screen, all of my reports would come up just fine, but the cursor change just wasn't "enough" of an indication that the application was still working on pulling the report - some of them can take a while - so I wanted to provide a more "obvious" visual cue.
In order to accomplish this, I've put the report creation method calls into a BackgroundWorker that exists in the loading screen itself (I haven't gotten around to learning how to use Async/Await well enough yet to feel comfortable using that instead). The loading screen comes up correctly and everything appears to work as expected until it actually attempts to display the report on screen. At that point, the "Please wait while the document is processing." box comes up (in the CrystalReportViewer control in the form used to display reports), but it just sits there, not even spinning. Eventually, my IDE throws an error about receiving a ContextSwitchDeadlock and I pretty much just have to cancel execution.
Here's my dlgReportLoading "splash screen" with a PictureBox control that contains an animated GIF:
Imports System.Windows.Forms
Public Class dlgReportLoading
Private DisplayReport As Common.CRReport
Private WithEvents LoadReportWorker As System.ComponentModel.BackgroundWorker
Public Sub New(ByRef Report As Common.CRReport)
InitializeComponent()
DisplayReport = Report
End Sub
Private Sub dlgReportLoading_Load(sender As Object, e As EventArgs) Handles Me.Load
Me.Cursor = Cursors.WaitCursor
Me.TopMost = True
Me.TopMost = False
LoadReportWorker = New System.ComponentModel.BackgroundWorker
LoadReportWorker.RunWorkerAsync()
End Sub
Private Sub dlgReportLoading_FormClosed(sender As Object, e As FormClosedEventArgs) Handles Me.FormClosed
Me.Cursor = Cursors.Default
End Sub
Private Sub LoadReport_DoWork(ByVal sender As Object, ByVal e As System.ComponentModel.DoWorkEventArgs) Handles LoadReportWorker.DoWork
If Not DisplayReport.ReportOption = Common.CRReport.GenerateReportOption.None Then
Select Case DisplayReport.ReportOption
Case Common.CRReport.GenerateReportOption.DisplayOnScreen
'-- This is the method I'm currently testing
DisplayReport.ShowReport()
Case Common.CRReport.GenerateReportOption.SendToPrinter
DisplayReport.PrintReport()
Case Common.CRReport.GenerateReportOption.ExportToFile
DisplayReport.ExportReport()
End Select
End If
DisplayReport.ReportOption = Common.CRReport.GenerateReportOption.None
'--
'-- This code was in use before trying to generate the reports in the background
'If Not DisplayReport.CrystalReport Is Nothing Then
' DisplayReport.CrystalReport.Dispose()
'End If
'--
End Sub
Private Sub LoadReport_Complete(ByVal sender As Object, ByVal e As System.ComponentModel.RunWorkerCompletedEventArgs) Handles LoadReportWorker.RunWorkerCompleted
Me.DialogResult = DialogResult.OK
Me.Close()
End Sub
End Class
As noted in the code above, I'm currently testing the ShowReport() method as defined here:
Protected Friend Sub ShowReport()
Dim ReportViewer As frmReportPreview
Me.PrepareReport()
ReportViewer = New frmReportPreview(Me)
With ReportViewer
.WindowState = FormWindowState.Maximized
.Show()
End With
End Sub
And the frmReportPreview is this:
Imports System.ComponentModel
Public Class frmReportPreview
Private DisplayReport As Common.CRReport
Private ReportToDisplay As CrystalDecisions.CrystalReports.Engine.ReportDocument
Public Sub New(ByRef Report As Common.CRReport)
InitializeComponent()
DisplayReport = Report
PrepareReportForDisplay()
Me.rptViewer.ReportSource = Nothing
Me.rptViewer.ReportSource = ReportToDisplay
' SET ZOOM LEVEL FOR DISPLAY:
' 1 = Page Width
' 2 = Whole Page
' 25-100 = zoom %
Me.rptViewer.Zoom(1)
Me.rptViewer.Show()
End Sub
Private Sub frmReportPreview_Shown(sender As Object, e As EventArgs) Handles Me.Shown
'-- HANGS HERE
Me.rptViewer.RefreshReport()
End Sub
Private Sub frmReportPreview_Closing(sender As Object, e As CancelEventArgs) Handles Me.Closing
ReportToDisplay.Dispose()
Me.rptViewer.ReportSource = Nothing
End Sub
'...CODE FOR PREPARING THE REPORT TO BE DISPLAYED
End Class
The dlgReportLoading form pops up correctly and the animation plays until the frmReportPreview pops up in front of it (it doesn't close). The little box that has what is normally an animated spinning circle indicating the report data is being loaded appears, but almost immediately freezes in place.
I have a breakpoint in the LoadReport_DoWork() method of my dlgReportLoading form after the call to the ShowReport() method, but it never gets to that point. I also have one in the LoadReport_Complete() method of that form that it never hits either and that dialog never actually closes.
I put another breakpoint at the end of the frmReportPreview_Shown method, right after the Me.rptViewer.RefreshReport() call, but it never hits that either, so it seems clear that this is where things are getting stuck, but only when the report is being generated through the BackgroundWorker. If I just call the ShowReport() method without sending it through the "splash screen" and BackgroundWorker, everything generates and displays normally.
I've tried putting the RefreshReport() method into its own BackgroundWorker with no change in the behavior. I've tried making the frmReportPreview object display modally with ShowDialog() instead of just Show(). None of this seems to help the issue.
I have a feeling something is being disposed of too early somewhere, but I can't figure out what that would be. I can provide the rest of the report preparation code from frmReportPreview if required, but that all seems to be working without error, as far as I can tell. I'm not averse to trying alternate methods of accomplishing my goal of showing the user a loading screen while all the report preparation is taking place - e.g., Async/Await or other multi-threading methods - so any suggestions are welcome. Please let me know if any additional clarification is needed.
ENVIRONMENT
Microsoft Windows 10 Pro 21H1 (OS build 19043.1348)
Microsoft Visual Studio Community 2017 (v15.9.38)
Crystal Reports for .NET Framework v13.0.3500.0 (Runtime version 2.0.50727)
EDIT: I forgot to mention that this whole mess is being called from a GenerateReport() method in my CRReport class defined as:
Public Sub GenerateReport(ByVal ReportGeneration As GenerateReportOption)
Me.ReportOption = ReportGeneration
If Me.ReportOption = GenerateReportOption.None Then
'...CODE FOR REQUESTING A GENERATION OPTION FROM THE USER
End If
Dim ReportLoadingScreen As New dlgReportLoading(Me)
ReportLoadingScreen.ShowDialog()
End Sub
Which, in turn, is being called from my main form like this:
Private Sub PrintMyXMLReport(ByVal XMLFile As IO.FileInfo)
Dim MyXMLReport As New IO.FileInfo("\\SERVER\Applications\Reports\MyXMLReport.rpt")
Dim Report As New Common.CRReport(MyXMLReport, XMLFile)
Report.GenerateReport(Common.CRReport.GenerateReportOption.DisplayOnScreen)
End Sub
You should separate the heavy lifting and UI operations into distinct methods in order to put them into the appropriate BackgroundWorker events:
Protected Friend Sub PrepareReport()
' perform long-running background work
End Sub
Protected Friend Sub ShowReport()
Dim ReportViewer = New frmReportPreview(Me) With {.WindowState = FormWindowState.Maximized}
ReportViewer.Show()
End Sub
Private DisplayReport As Common.CRReport
Private Sub LoadReport_DoWork(ByVal sender As Object, ByVal e As System.ComponentModel.DoWorkEventArgs) Handles LoadReportWorker.DoWork
DisplayReport.PrepareReport()
End Sub
Private Sub LoadReport_Complete(ByVal sender As Object, ByVal e As System.ComponentModel.RunWorkerCompletedEventArgs) Handles LoadReportWorker.RunWorkerCompleted
DisplayReport.ShowReport()
Me.DialogResult = DialogResult.OK
Me.Close()
End Sub
because LoadReport_DoWork actually runs on a new non-UI thread, and LoadReport_Complete runs on the caller thread, which is a UI thread. Only there can you interact with the UI and show Forms etc.
I relise there is so many other questions out there regarding the progressbar, though I've looked through them "all" and can not find one that works.
I am trying to upload c:\screenshot.png to my ftp with a progress bar and a msgbox once finished.
Could someone provide a working example for me?
Thankyou
Edit heres the code I tried. Uploading works, though the progress bar dosent.
Sub UpdateProgressBar(ByVal sender As Object, ByVal e As UploadProgressChangedEventArgs)
If ProgressBar1.InvokeRequired Then
ProgressBar1.Invoke(New UploadProgressChangedEventHandler(AddressOf UpdateProgressBar), sender, e)
Exit Sub
End If
ProgressBar1.Value = CInt(ProgressBar1.Minimum + _
((ProgressBar1.Maximum - ProgressBar1.Minimum) * _
e.ProgressPercentage) / 100)
End Sub
Private Sub btnUpload_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button8.Click
Label16.Text = "Uploading now..."
Label16.Update()
Dim client As New System.Net.WebClient()
AddHandler client.UploadProgressChanged, AddressOf UpdateProgressBar
With client
.Credentials = New NetworkCredential( _
"damon#slimar.eu", "mine123!")
.UploadFile("ftp://slimar.eu/screenshot.png", "C:\screenshot.png")
End With
Label16.Text = "Done!"
Label16.Update()
End Sub
Progress bar has minValue,Max value, StepValue which is used to perform a step and Value to setup arbitray value.When you uploading a file or downloading you should be able to see via e paramenter total byte and actual byte trasmission.So you can setup Progress bar value and max value.
Also personally i invite you to use backgroundworker which :
Not Freeze GUI
Give you much controll on thread with no issue and no invoke needs
Make it more simple :)
Public Class Form1
Dim Iclick, submit
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Iclick.InvokeMember("click")
With WebBrowser1.Document
For l_index As Integer = 0 To ListBox1.Items.Count - 1
Dim l_text As String = CStr(ListBox1.Items(l_index))
.All("input").InnerText = l_text
System.Threading.Thread.Sleep(5000)
Next
'.All("input").InnerText = "http://wordpress.com"
End With
submit.InvokeMember("click")
End Sub
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
WebBrowser1.Navigate("http://whatwpthemeisthat.com")
End Sub
Private Sub WebBrowser1_DocumentCompleted(ByVal sender As System.Object, ByVal e As System.Windows.Forms.WebBrowserDocumentCompletedEventArgs) Handles WebBrowser1.DocumentCompleted
Iclick = WebBrowser1.Document.GetElementById("input")
submit = WebBrowser1.Document.GetElementById("check")
End Sub
End Class
This is my code so far I have a ListBox with URLs I want to check using web browser which theme are they running (if they are wordpress) but the program seems to be bugged when I click START it is NOT responding, until the last element. It has to do something with the system.threading.thread.sleep line but I don't know what am I doing wrong? Thanks.
That's excactly what the Thread.Sleep() method is for. It freezes for 5 seconds.
Also you are replacing the input each time the For loop repeats. So it replaces, waits 5 seconds, replaces, waits 5 sec... and so on.
I guess you are trying to click the submit button for each of the elements, but that's not what you are doing. You have to hit the submit button each time the text has changed. However you really can't be sure about the loading time of the page.
I'd suggest you to place the submit-part inside the loop, then wait, then go into the next iteration. Maybe you could even try to run the website multiple times, one for each listbox item and then apply the right text to the controls in the webpage, hit the button and receive your result.
EDIT: Your best bet for the Thread.Sleep() would be creating a new thread in which you place the loop. This thread can be paused for 5 seconds, and your application will still respond. This is how you create one:
Imports System.Threading.Thread
Dim myThread as Thread
'//..........
'//Button1 is clicked ->
myThread = new Thread (AddressOf myLoop)
myThread.start()
'//..........
Private Sub myLoop ()
'// Loop goes here...
'Sleeping here will only affect the thread that runs this sub. Your form will still be available
End Sub
Hey all i am in need of some help getting my code working correctly like i am needing it to. Below is my code that when the user click on the textbox, it pops up a keyboard where they can click on any letter and it will type that letter into the textbox. Problem being is i can not seem to get the name of the text box to return so that it knows where to send the letters to.
Order in firing is:
TextBox1_MouseDown
keyboardOrPad.runKeyboardOrPad
kbOrPad.keyboardPadType
ClickLetters
Form1.putIntoTextBox
Form1
Private Sub TextBox1_MouseDown(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles TextBox1.MouseDown
Call keyboardOrPad.runKeyboardOrPad("SHOW") 'Just shows the keyboard
Call kbOrPad.keyboardPadType("PAD", TextBox1)
End Sub
Public Sub putIntoTextBox(ByRef what2Put As String, ByRef whatBox As TextBox)
whatBox.Text = what2Put '<-- has error Object reference not set to an instance of an object. for the whatBox.text
End Sub
kbOrPad class
Dim theBoxName As TextBox = Nothing
Public Sub keyboardPadType(ByRef whatType As String, ByRef boxName As TextBox)
theBoxName = boxName '<-- shows nothing here
Dim intX As Short = 1
If whatType = "PAD" Then
Do Until intX = 30
Dim theButton() As Control = Controls.Find("Button" & intX, True)
theButton(0).Enabled = False
intX += 1
Loop
ElseIf whatType = "KEYB" Then
End If
End Sub
Private Sub ClickLetters(ByVal sender As System.Object, ByVal e As System.EventArgs)
Dim btn As Button = CType(sender, Button)
If btn.Text = "Backspace" Then
Else
Call Form1.putIntoTextBox(btn.Text, theBoxName) 'theBoxName taken from keyboardPadType
End If
End Sub
Some visuals for you:
Pastebin code: http://pastebin.com/4ReEnJB0
make sure that theBoxName is a Module scoped variable, then I would populate it like this giving you the flexibility of implementing a shared TextBox MouseDown Handler:
Private Sub TextBox1_MouseDown(sender As System.Object, e As System.Windows.Forms.MouseEventArgs) Handles TextBox1.MouseDown
Dim tb As TextBox = CType(sender, TextBox)
Call keyboardPadType("PAD", tb)
End Sub
Try something like this
Public Class Form1
Dim myKborPad As New kbOrPad
Private Sub TextBox1_MouseDown(sender As System.Object, e As System.Windows.Forms.MouseEventArgs) Handles TextBox1.MouseDown
Dim tb As TextBox = CType(sender, TextBox)
Call myKborPad.keyboardPadType("PAD", tb)
End Sub
Edit Based on your PasteBin code.
I noticed you already have an instance of your keyboardPadType declared in your Module, use that instead of what I said earlier. That code should look like:
remove:
Dim myKborPad As New kbOrPad
and use the theKbOrPad that you created in your module like this:
Private Sub TextBox1_MouseDown(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles TextBox1.MouseDown
Dim tb As TextBox = CType(sender, TextBox)
Call keyboardOrPad.runKeyboardOrPad("SHOW")
Call theKbOrPad.keyboardPadType("PAD", tb)
'Call kbOrPad.keyboardPadType("PAD", tb)
End Sub
Also about the current error your are getting, you are trying to use the default instance of your Form1 , it isn't the actual Form that you are running, you can code around this by making the method you are trying to use as shared. Like this:
Public Shared Sub putIntoTextBox(ByRef what2Put As String, ByRef whatBox As TextBox)
whatBox.Text = what2Put
End Sub
But however I would actually prefer to put it into your Module like this
Public Sub putIntoTextBox(ByRef what2Put As String, ByRef whatBox As TextBox)
whatBox.Text = what2Put
End Sub
and call it like this
Call putIntoTextBox(btn.Text, theBoxName)
after making above changes your code worked.
First, you should replace the ByRef with ByVal (anytime you don't know whether you should use one or the other, use ByVal).
Secondly, I believe you don't need the method, putIntoTextBox, I think you should be able to do that directly (might be threading problems that prevent it, but I don't think that's likely based on your description). You don't show where Form1 is set (or even if it is), and that's another potential problem.
Finally, the better way to call back into the other class is to use a delegate/lambada.
(I know, no code, but you don't provide enough context for a working response, so I'm just giving text).
I'm migrating an application from VB6 to VB.Net and I found a change in the behavior of the ListBox and I'm not sure of how to make it equal to VB6.
The problem is this:
In the VB6 app, when the ListBox is focused and I type into it, the list selects the element that matches what I type. e.g. If the list contains a list of countries and I type "ita", "Italy" will be selected in the listbox.
The problem is that with the .Net version of the control if I type "ita" it will select the first element that starts with i, then the first element that starts with "t" and finally the first element that starts with "a".
So, any idea on how to get the original behavior? (I'm thinking in some property that I'm not seeing by some reason or something like that)
I really don't want to write an event handler for this (which btw, wouldn't be trivial).
Thanks a lot!
I shared willw's frustration. This is what I came up with. Add a class called ListBoxTypeAhead to your project and include this code. Then use this class as a control on your form. It traps keyboard input and moves the selected item they way the old VB6 listbox did. You can take out the timer if you wish. It mimics the behavior of keyboard input in Windows explorer.
Public Class ListBoxTypeAhead
Inherits ListBox
Dim Buffer As String
Dim WithEvents Timer1 As New Timer
Private Sub ListBoxTypeAhead_KeyDown(sender As Object, _
e As System.Windows.Forms.KeyEventArgs) Handles Me.KeyDown
Select Case e.KeyCode
Case Keys.A To Keys.Z, Keys.NumPad0 To Keys.NumPad9
e.SuppressKeyPress = True
Buffer &= Chr(e.KeyValue)
Me.SelectedIndex = Me.FindString(Buffer)
Timer1.Start()
Case Else
Timer1.Stop()
Buffer = ""
End Select
End Sub
Private Sub ListBoxTypeAhead_LostFocus(ByVal sender As Object, _
ByVal e As System.EventArgs) Handles Me.LostFocus
Timer1.Stop()
Buffer = ""
End Sub
Public Sub New()
Timer1.Interval = 2000
End Sub
Private Sub Timer1_Tick(sender As Object, e As System.EventArgs) Handles Timer1.Tick
Timer1.Stop()
Buffer = ""
End Sub
End Class
As you probably know, this feature is called 'type ahead,' and it's not built into the Winform ListBox (so you're not missing a property).
You can get the type-ahead functionality on the ListView control if you set its View property to List.
Public Function CheckIfExistInCombo(ByVal objCombo As Object, ByVal TextToFind As String) As Boolean
Dim NumOfItems As Object 'The Number Of Items In ComboBox
Dim IndexNum As Integer 'Index
NumOfItems = objCombo.ListCount
For IndexNum = 0 To NumOfItems - 1
If objCombo.List(IndexNum) = TextToFind Then
CheckIfExistInCombo = True
Exit Function
End If
Next IndexNum
CheckIfExistInCombo = False
End Function