I'm new to VB but recently created my first working app :) Anyway it just compresses files and little bit more. The latest thing that I added was a marquee style progress bar to animate while the operation was in progress and stop when it ends and the user can do the next zip operation. The progress bar wasn't updating, so I used a background worker to do the actual task while the button click just did the animation. Since then I've notcied serious degredation in the app. It struggles to load. I even got an out of memory error. Not sure if the background worker is related, but I thought I'd mention as it was the last update. Has anyone experienced anything similar? If I can provide and specific info, please ask me for it! Many thanks.
UPDATE: So I understand that I'm not using the BGWorker correctly. I will change that. But I found even with that removed, I still had issues. So I created a new form and started adding in bits of my code one by one. Anyway, I fell at the first hurdle with my form load sub. So I added that in slowly. I found that when ever I have any statements that load a variable from settings for persistent settings that the app falls over. Below is my code. Can anyone see what's up?????
UPDATE: I've found that if I load from settings the memory useage shoots up. I tried this too with saving settins on form closed. Below is the error received. The same out of memory occurs when trying to load settings too. I never experienced this on the first form I created. So perhaps I have missed some settings on the second, because the implementation in the code hasn't changed.
System.Configuration.ConfigurationErrorsException: Failed to save settings: An error occurred executing the configuration section handler for userSettings/Backup_Tool.My.MySettings. ---> System.Configuration.ConfigurationErrorsException: An error occurred executing the configuration section handler for userSettings/Backup_Tool.My.MySettings. ---> System.OutOfMemoryException: Exception of type 'System.OutOfMemoryException' was thrown
This is when I added in the code below:
Private Sub Form1_Closed(sender As Object, e As EventArgs) Handles MyBase.FormClosed
' TAB PAGE 1.
' Save controls to settings.
My.Settings.StartPathTextBox1 = StartPathTextBox1.Text
My.Settings.ZipPathTextBox1 = ZipPathTextBox1.Text
My.Settings.CopyPathTextBox1 = CopyPathTextBox1.Text
My.Settings.ZipSelectCheckBox1 = ZipSelectCheckBox1.Checked
My.Settings.CopySelectCheckBox1 = CopySelectCheckBox1.Checked
For Each s As String In StartNameListBox1.Items()
My.Settings.StartNameListBoxItems1.Add(s)
Next
For Each s As String In StartNameListBox1.SelectedItems()
My.Settings.StartNameListBoxSelectedItems1.Add(s)
Next
End Sub
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
' FORM 1.
' Initialise specialised string collections.
If My.Settings.StartNameListBoxItems1 Is Nothing Then
My.Settings.StartNameListBoxItems1 = _
New System.Collections.Specialized.StringCollection
End If
If My.Settings.StartNameListBoxSelectedItems1 Is Nothing Then
My.Settings.StartNameListBoxSelectedItems1 = _
New System.Collections.Specialized.StringCollection
End If
' TAB PAGE 1.
' Restore controls from saved settings.
StartPathTextBox1.Text() = My.Settings.StartPathTextBox1
ZipPathTextBox1.Text() = My.Settings.ZipPathTextBox1
CopyPathTextBox1.Text() = My.Settings.CopyPathTextBox1
ZipSelectCheckBox1.Checked = My.Settings.ZipSelectCheckBox1
CopySelectCheckBox1.Checked = My.Settings.CopySelectCheckBox1
For Each s As String In My.Settings.StartNameListBoxItems1()
StartNameListBox1.Items.Add(s)
Next
For Each s As String In My.Settings.StartNameListBoxSelectedItems1()
StartNameListBox1.SelectedItems.Add(s)
Next
' Decide controls initial states.
If StartNameListBox1.SelectedItems.Count = 0 Then
ZipSelectCheckBox1.Enabled = False
RunButton1.Enabled = False
End If
If ZipSelectCheckBox1.Checked = False Then
ZipPathTextBox1.Enabled = False
ZipBrowseButton1.Enabled = False
End If
If ZipPathTextBox1.Text = String.Empty Then
CopySelectCheckBox1.Enabled = False
End If
If CopySelectCheckBox1.Checked = False Then
CopyPathTextBox1.Enabled = False
CopyBrowseButton1.Enabled = False
End If
End Sub
It appears to be that you are only ever adding the current selections to the Settings collections. You might well clear the ListBox when they make new selections, but you do not do the same thing with the Settings Collections like My.Settings.StartNameListBoxItems1:
For Each s As String In StartNameListBox1.Items()
My.Settings.StartNameListBoxItems1.Add(s)
Next
The collection will have all the items in it from all the other times it has ever run already and you are now going to add more to it. Eventually you will have many, many, many items in it.
My.Settings.StartNameListBoxItems1.Clear ' REMOVE ALL OLD ITEMS
' Save just the current items to the collection
For Each s As String In StartNameListBox1.Items()
My.Settings.StartNameListBoxItems1.Add(s)
Next
use .Clear on both Collections
Related
I'm running the following loop successfully when the number of items is low. However, when run against a larger list on the ListView, it seems to be taking way too long. I tested it with a list of 8,700 files and it took about two hours to complete. Is there something I can do to speed this up? I guess that removing the check for the Cancel button would help but I would like to keep that there for usability. As I've mentioned in earlier posts, I'm pretty new to Visual Basic so please provide lots of explanation with your suggestions. Thanks. Here's the code:
For i As Integer = 0 To m_CountTo
' Has the background worker be told to stop?
If BackgroundWorker1.CancellationPending Then
' Set Cancel to True
e.Cancel = True
Exit For
End If
'Select the row from the LVFiles ListView, then move the first column (0) into strSourceFilePath and the last
' column (3) into strDestFilePath. Execute the CopyFile method to copy the file.
LVFiles.Items(i).Selected = True
strSourceFilePath = LVFiles.SelectedItems(i).SubItems(0).Text
strDestFilePath = LVFiles.SelectedItems(i).SubItems(3).Text
My.Computer.FileSystem.CopyFile(strSourceFilePath, strDestFilePath, overwrite:=False)
' Report The progress of the Background Worker.
BackgroundWorker1.ReportProgress(CInt((i / m_CountTo) * 100))
' Me.LabelStatus.Text = FormatPercent((i + 1) / (intLVIndex + 1), 2) ' Show Percentage in Label
SetLabelText_ThreadSafe(Me.LabelStatus, FormatPercent(i / m_CountTo, 2))
Next
The Backgroundworker encapsulates a new thread. You cannot directly access controls that are created in another thread. If you do you will get an InvalidOperationException because of a cross-thread operation. The Backgroundworker however offers some functionality to share data (or access to controls) between threads. You should use them.
Private Sub StartBGW_Click(sender As Object, e As EventArgs) Handles StartBGW.Click
Dim dict As New Dictionary(Of String, String)
For i As Integer = 0 To m_CountTo
dict.Add(Me.LVFiles.Items(i).SubItems(0).Text,
Me.LVFiles.Items(i).SubItems(3).Text)
Next
Me.BackgroundWorker1.RunWorkerAsync(dict)
End Sub
First we prepare a dictionary that contains the source as Key and the target as Value. This object is given to the BackgroundWorker as a parameter.
Now comes the essential part:
Private Sub BackgroundWorker1_DoWork(sender As Object, e As System.ComponentModel.DoWorkEventArgs) Handles BackgroundWorker1.DoWork
Dim counter As Integer = -1
Dim dict = DirectCast(e.Argument, Dictionary(Of String, String))
For Each kvp In dict
counter += 1
' Has the background worker be told to stop?
If Me.BackgroundWorker1.CancellationPending Then
' Set Cancel to True
e.Cancel = True
Exit For
End If
'Select the row from the LVFiles ListView, then move the first column (0) into strSourceFilePath and the last
' column (3) into strDestFilePath. Execute the CopyFile method to copy the file.
My.Computer.FileSystem.CopyFile(kvp.Key, kvp.Value, overwrite:=False)
' Report The progress of the Background Worker.
Me.BackgroundWorker1.ReportProgress(CInt((counter / m_CountTo) * 100), counter)
Next
End Sub
We don't access the ListView anymore. Instead we use the dictionary that is given to us as a parameter through e.Argument. Theres also a slight difference in the BackgroundWorker1.ReportsProgress line. There's a second parameter I have used to pass the current index to the ProgressChanged event which can be obtained via e.UserState.
Private Sub BackgroundWorker1_ProgressChanged(sender As Object, e As System.ComponentModel.ProgressChangedEventArgs) Handles BackgroundWorker1.ProgressChanged
Me.LVFiles.Items(Convert.ToInt32(e.UserState)).Selected = True
Me.LabelStatus.Text = e.ProgressPercentage.ToString
End Sub
This event is designed to be raised with a SynchronizationContext of the calling thread, in this case the UI thread. Here we can safely access any control and update them. The index is passed as e.UserState, so we can access the relevant item and set their Selected property to true.
The biggest improvement comes from the change of Me.LVFiles.SelectedItems(i).SubItems(0).Text to Me.LVFiles.Items(i).SubItems(0).Text. I'm not a professional, but it seems that SelectedItems isn't a real list. Instead it iterates through every item using the SendMessage API until the desired index is reached. This is why it takes longer the higher your index is. Everytime it starts with the first item and iterates through them. Lot of operations.
The second improvement is the separation of code that access UI controls. It's all done in one method now. More clear and readable.
Update: #Enigmativity mentioned that SelectedListViewItemCollection implements IList and therefore is a real list. Even though it has no underlying list containing all selected items like you have in ListViewItemCollection. My point was to say, that accessing a single element is more complicated.
I'm trying to copy Files from a local Computer to a Network device. I'm trying to get a Progress Bar working for the File copy, and got it working for a Single Directory with no Subdirectory:
Private Sub CopyPictures()
Try
If Not Directory.Exists(DestinationPath) Then
My.Computer.FileSystem.CreateDirectory(DestinationPath)
End If
Dim counterLocalFiles = My.Computer.FileSystem.GetFiles(SourcePath)
UpdateProgressBarMaximum1(CInt(counterLocalFiles.Count))
UpdateLabelText2(CStr(counterLocalFiles.Count)) 'is a label which shows copied X files of Label2 Files
fsw1 = New IO.FileSystemWatcher(DestinationPath)
fsw1.EnableRaisingEvents = True
My.Computer.FileSystem.CopyDirectory(SourcePath, DestinationPath)
GetSettingsFromFile()
Catch Exec As System.IO.IOException
Dim dr As DialogResult = MessageBox.Show("Some Random Error Code", "Exception Title", MessageBoxButtons.OKCancel)
If (Not DialogResult.OK = dr) Then
Exit Sub
Return
End If
End Try
End Sub
Private Sub fsw1_Created(sender As Object, e As FileSystemEventArgs) Handles fsw1.Created
Dim counterRemoteFiles = My.Computer.FileSystem.GetFiles(DestinationPath)
UpdateProgressBar1(CInt(counterRemoteFiles.Count))
UpdateLabelText1(CStr(counterRemoteFiles.Count))
End Sub
The Update ObjectX Subs are just invoke Functions since the CopyPictures is raised by a backgroundworker as well looking all like this one for example
Private Sub UpdateProgressBar1(Value As Int32)
If ProgressBar1.InvokeRequired Then
ProgressBar1.Invoke(New Action(Of Integer)(AddressOf UpdateProgressBar1), Value)
Else
'We are on the UI thread so update the control.
ProgressBar1.Value = Value
End If
End Sub
This code works perfectly fine for me, but I have to deal with SubDirectories which contain the Images, and the names of the subs are random so i cant predetermine them so I came up with slight changes:
The Counter is looking now like this:
Dim counterLocalFiles = System.IO.Directory.GetFiles(SourcePath, "*.jpg*", SearchOption.AllDirectories).Length
UpdateProgressBarMaximum1(CInt(counterLocalFiles))
UpdateLabelText2(CStr(counterLocalFiles))
And this:
Dim counterRemoteFiles = IO.Directory.GetFiles(DestinationPath, "*.jpg", SearchOption.AllDirectories).Length
UpdateProgressBar1(CInt(counterRemoteFiles))
UpdateLabelText1(CStr(counterRemoteFiles))
And I added:
fsw1.IncludeSubdirectories = True
Now the weired Problems started: It would properly count the file in the source Directory setting label2 to the correct amount of files in all subdirectories and then start copying. It would NOT update the Progressbar though in real time. It just updated it once when it was done with the first directory and just adding the amount of files to it which it contained. After that it completly stoppedd nored the second directory and didn't add that at all to the progressbar. What am I doing wrong here? I hope my english is fine, If you have any question or If I was not clear enough, please let me know. Thank you
You don't have an event consumer that triggers your progressbar update routine - you call it once when your filesystemwatcher is instantiated.
You need to declare an event that handles the copy event and fires off your progress update code. Because Filesystemwatcher cannot monitor network drives, you may want to declare an event that fires off your progress update method when the counterRemoteFiles count increments.
Turns out I just made a mistake with correctly putting the
fsw1.IncludeSubdirectories = True
I was setting it to true in the Form Editor instead of doing it in the code. Once i actually put that in the code after initialising the fsw, it would work just fine
Currently, I am utilizing ActiveReports to implement a dynamic image via pathname into a report that is generating.
The Images are being automatically generated as .jpg to a server folder. The Active Reports module imports the files using this code.
Sub ActiveReport_ReportStart
Picture1.Image = System.Drawing.Image.FromFile("path\filename.jpg")
End Sub
The problem I am running into is that this report locks out the jpgs from being overwritten.
I am unsure what could be going wrong, but it seems that the report is still using the image files after the report has been generated.
Am I missing a "disconnect" code piece to ensure that an import doesn't allow for continued contact to the file?
I apologize if this is simple, but I can't find anything for this specific instance.
Thank you.
EDIT:
I attempted to get around the lockout by copying them into their own variable. But this didn't work either.
Sub ActiveReport_ReportStart
dim TempImage as Image = Image.FromFile("path\filename")
Picture1.Image = TempImage
End Sub
You can use "Using" block to make sure that the object of the image is disposed as soon as its usage is completed.
Using statement basically marks a boundary for the objects specified in the statement. So when code block using Using – End Using is exited either after normal execution or some exception cause, the framework invokes the Dispose method of these objects automatically.
Here is the suggested code which can be helpful for you in resolving the issue:
Private Sub SectionReport1_ReportStart(sender As Object, e As EventArgs) Handles MyBase.ReportStart
Dim img As Image
Using bmpTemp = New Bitmap("path\filename.jpg")
img = New Bitmap(bmpTemp)
End Using
Picture1.Image = img
End Sub
I was able to get this to work by creating a function that used the Graphics.FromImage method and disposed the original file.
Public Function GetImageFile(ByVal pathfn As String) As Image
Dim tempImg As Image = Image.FromFile(pathfn)
Dim tempBtm As New Bitmap(Width:=img.Width*CorrectFactor, Height:=img.Height*CorrectFactor, Format:=tempImg.PixelFormat)
Using g As Graphics = Graphics.FromImage(bm)
g.DrawImage(tempImg, Point.Empty)
End Using
tempImg.Dispose()
Return tempBtm
End Function
The item that would be placed in the report would be as follows.
Sub ActiveReport_ReportStart
Picture1.Image = GetImageFile("Path\Filename")
End Sub
My goal is to create a VB application that reads and writes information to various webpages loaded in Internet explorer.
I have created a program that works exactly as I intend in VBA. I am now trying to re-implement the same programming in VB.
I have a function that looks for and returns an Internet Explorer Object where the input matches the LocationName.
Assuming the target page is loaded, I can work with it. Methods such as getElementByID() work perfectly. If the browser window is closed and reopened, and the code is run again, the results are very inconsistent. The getIE function seems to work, but when trying to use methods like document.getElementByID() a NullReferenceException is thrown.
Does anyone know if there is anything I am missing that I need to include to get the document property to update?
EDIT: I have looked over the NullReferenceException article. It hasn't helped me unfortunately. In case I was unclear in my wording, I would like to reiterate that the same bit of code yields a different result when executed the 2nd time under the same conditions (same webpage open in Internet Explorer).
On the second execution IE.locationName is retrievable but IE.Document.title is not. The problem is definitely with the Document property as far as I can tell. I am truly stumped.
Many thanks
Public Function getIE(targetTitle As String) As SHDocVw.InternetExplorer
' Create the shell application and Collection of open windows
Dim shellObj As Object = CreateObject("Shell.Application")
Dim shellWindows As SHDocVw.ShellWindows = shellObj.Windows()
getIE = Nothing
' Scan through the Collection
For I = (shellObj.Windows.Count - 1) To 0 Step -1
' If found, assign this to the function output and exit early
If InStr(shellWindows(I).LocationName, targetTitle) Then
getIE = shellWindows(I)
Debug.Print("Found: " & shellWindows(I).LocationName)
Exit For
End If
Next I
End Function
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim IE As SHDocVw.InternetExplorer
IE = getIE("my site title")
If IE Is Nothing Then
Debug.Print("Site not open")
Exit Sub
End If
' The code always gets this far, and despite the page being found, starts throwing exceptions from here on if the window has been closed and reopened whilst my application has stayed running.
' Sample form data insertion code
IE.Document.getElementById("textbox1").value = "my value"
' Click the submit button
IE.Document.getElementById("submit").click()
' Wait for page to load
While IE.Busy
End While
IE.Document.getElementById("textbox2").value = "my 2nd value"
' done
IE = Nothing
End sub
I have created a chart in Access forms and exported it in Image Format. It's easily done, but the problem comes when after it, when I close the Form, It Shows a Pop-up message.
"The operation on the Chart object failed.
The OLE server may not be registered.
To register the OLE server, reinstall it. "
Then I have done some change and the Code looks Like:
Private Sub Command1_Click()
Dim grpApp As Graph.Chart
Set grpApp = Me.Graph1.Object
grpApp.Export "C:\Graph1.jpg", "JPEG"
Me.Graph1.Enabled = True
Me.Graph1.Locked = False
Set grpApp = Nothing
Me.Graph1.Action = acOLEClose
End Sub
Now the problem is that after the export is done, the chart becomes bad, the fonts were big
and condensed and the bars looked short...
I'm really stuck..
After trying various workarounds, I found pretty much the same question and a proper fix for the problem:
Try unlocking the graph before the export, and restore the lock afterwards
'Unlock the control...
Me!YourOLEChart.Locked = False
Me!YourOLEChart.Enabled = True
'Do the actual export...
Set oleGrf = Me!YourOLEChart.Object
oleGrf.Export filename, "JPEG"
Set oleGrf = Nothing
Me!YourOLEChart.Action = acOLEClose
'Restore the lock...
Me!YourOLEChart.Locked = True
Me!YourOLEChart.Enabled = False
Important: remember to set the Action acOLEClose to avoid the OLE server from crashing.
You are not alone—I had the same problem. On several runs of the form, after the export execution, the chart/graph/OLEFrame became wrong (on the form View), its format got changed and I hadn't known why.