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Attempted to read or write protected memory. When I call showDialog method of openfileDialog
Not sure why. It was originally working just fine, then I made some changes to the code that should have had no effect on this.
The changes I made where to just change some properties of a checkbox when the file is selected:
Private Sub OpenFileDialog1_FileOk(ByVal sender As System.Object, ByVal e As System.ComponentModel.CancelEventArgs)
attachmentLabel.Text = OpenFileDialog1.FileName.ToString()
attachmentCheckBox.Visible = True
attachmentCheckBox.Checked = True
End Sub
Here's the event handler that calls OpenFileDialog1.ShowDialog()
Private Sub Button2_Click(sender As System.Object, e As System.EventArgs) Handles Button2.Click
OpenFileDialog1.Title = "Please Select a File"
OpenFileDialog1.InitialDirectory = "C:temp"
OpenFileDialog1.ShowDialog()
End Sub
Any help would be appreciated.
When the exception occurs, the values for e and sender say "unable to evaluate expression".
(This is really a comment, but it is too big.)
It is due to:
some of your code not shown here,
some filesystem or networking issue specific to your machine, or
a transient problem with VisualStudio (or the VB.NET compiler).
To rule out (3), (and (2) if the problem is transient) reboot your machine and rebuild your application (either clean and then build or at least just rebuild).
To confirm (2), try running your program on a different machine.
To help locate the issue if it is (1), search your code for references to OpenFileDialog1. If it appears anywhere other than in designer generated code and the two events you have shown in your question, include them in your question.
If the problem does still occur, confirm if it occurs with both Debug and Release builds or not, and include the designer generated code in the question as well.
Related
EDIT (Important!): This question din't make sense before, and even though I have the answer from a loong time ago I decided to update it with some acual code. Probably all comments will be irrelevant because the old post contained code that had nothing to do with the question.
I'm trying to get the URL off the current loading/loaded page in GeckoWebBrowser. I only have one idea on how I can get it:
Private Sub Browser_Navigated(ByVal sender As Object, ByVal e As System.Windows.Forms.WebBrowserNavigatedEventArgs) Handles Browser.Navigated
someLabel.Text = GeckoWebBrowser.DocumentTitle
End Sub
The error I am getting is that it is not updating.
Trying to use an access database with Visual studio 15. After failure I found a number of tutorials and followed them with a new project and new database.
The database is connecting but the data inside the database won't display (although no error) and even using the built in save function in VB results in a run time error.
If anyone can point me in the right direction I'd be grateful. Code below.
Public Class Form1
Private Sub CustomersBindingNavigatorSaveItem_Click(sender As Object, e As EventArgs) Handles CustomersBindingNavigatorSaveItem.Click
Me.Validate()
Me.CustomersBindingSource.EndEdit()
Me.TableAdapterManager.UpdateAll(Me.CustomersDataSet) 'Error is here****
End Sub
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
'TODO: This line of code loads data into the 'CustomersDataSet.Customers' table. You can move, or remove it, as needed.
Me.CustomersTableAdapter.Fill(Me.CustomersDataSet.Customers)
End Sub
Private Sub BindingNavigatorDeleteItem_Click(sender As Object, e As EventArgs) Handles BindingNavigatorDeleteItem.Click
End Sub
Private Sub BindingNavigatorAddNewItem_Click(sender As Object, e As EventArgs) Handles BindingNavigatorAddNewItem.Click
End Sub
End Class
The error message I get is An unhandled exception of type 'System.Data.OleDb.OleDbException' occurred in System.Data.dll
Additional information: Unspecified error.
Here is a video that I made a while ago that should be able to help you, If you have any questions about it, i can definitely help you out.
https://www.youtube.com/watch?v=vvzY0LsAUNE
Also do you definitely need to use Access? I would recommend using an SQL database because when you publish your program, the end user may have to have a link to your access database in the same spot as yours, which can be a pain.
Nevertheless here is a video i also made regarding setting up an SQL database via Visual Studio.
https://www.youtube.com/watch?v=NLs44hxV514
If you have any issue, leave a comment and i will be happy to help you out :)
Keep In Mind
Don't forget that you need to also have a Number/unique word/or something a like in the Primary key column even if you haven't added any details to the database. eg Name and so on. If not your program may crash, so you could use the Try statement to fix this issue if the Primary Key column is left empty.
I am creating an application for an Arma 3 server that directly launches the game and connects the user to a specific server. The problem that I am encountering, being the relatively new VB coder that I am, is that the Arma3battleye.exe directory (the .exe used to launch the game) may be installed in different directories depending on where the user originally installed it. I've developed the code to connect the user to the server if they've installed Arma in the normal location:
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Process.Start("C:\Program Files (x86)\Steam\steamapps\common\Arma 3\arma3battleye.exe", "2 1 -noSplash -skipIntro -useBE -noPause -world=empty -connect=192.99.36.80 -port=2505 -mod=#Exile;#AlRayak;#AllInArmaTerrainPack;#CUP Units;#CUP Vehicles;#CUP Weapons;#CBA_A3;#TRYK's Multi-Play Unifrom's pack")
End Sub
However, after researching for many hours, I cannot determine how to have the program automatically determine the install directory of the arma3batteye.exe and then execute it with all of the correct start parameters included. Any solutions or pointers to help solve this problem would be greatly appreciate.
TLDR: What is the easiest way to program an application to automatically find the install directory of a given .exe and then execute it with the given parameters as I've done above?
Edit: Another thread similar to mine asks a similar question (how to view/get to the steam folder without hard coding it. They arrive at the conclusion that if you do (for winx32):
Dim strSteamInstallPath as String = My.Computer.Registry.GetValue(
"HKEY_LOCAL_MACHINE\SOFTWARE\Valve\Steam", "InstallPath", Nothing)
Or using this registry location for winx64:
HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Valve\Steam
and then were to create a button using Process.Start that it would allow you to ultimately view the directory. At this point I haven't discovered a way for that to translate into being able to execute the battleyearma3.exe from within that steam directory with the proper parameters. While it seems this code may be useful in arriving at the solution I'm looking for, I can only get the program to view the general steam directory at this time.
edit: Solution posted at bottom. Thanks to #VisualVincent who was really the one that allowed me to complete this. It really should be you having posted the correct answer, not me.
I would use the registry...
You add a key like HKEY_LOCAL_MACHINE\Software\Arma3\ServerPath = "..." when you install the server.
And whenever you need to start the client, you check up the path from that registry key.
So with the comments and tips you gave me (especially #VisualVincent) I managed to piece enough stuff together to solve my issue. Thanks to everyone for the help:
First I declared 2 variables. The first one (BattleyePath) goes into the registry as far as I can get it to dig. Executing this variable on its own will open the users steam directory. I then declared a second variable (BattleyePath2) which uses IO.Path.Combine get to the directory the users Arma3.exe is installed in:
Dim BattleyePath As String = My.Computer.Registry.GetValue("HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Valve\Steam", "InstallPath", Nothing)
Dim BattleyePath2 As String = IO.Path.Combine(BattleyePath, "SteamApps", "common", "Arma 3", "arma3battleye.exe")
I added a couple buttons to close the program and mute the sound:
`Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
Me.Close()
End Sub
Private Sub Button3_Click(sender As Object, e As EventArgs) Handles Button3.Click
My.Computer.Audio.Stop()
End Sub`
Finally I created the button that actually launches the game:
`Private Sub Button4_Click_1(sender As Object, e As EventArgs) Handles Button4.Click
Process.Start(BattleyePath2, "2 1 -noSplash -skipIntro -useBE -noPause -world=empty -connect=192.99.36.80 -port=2505 -mod=#Exile;#AlRayak;#AllInArmaTerrainPack;#CUP Units;#CUP Vehicles;#CUP Weapons;#CBA_A3;#TRYK's Multi-Play Unifrom's pack")
End Sub`
On my form I have a menu with "file-save". When I click save I want to save particular settings to restore when the form is closed and re-opened. I've done this successfully for text in text-boxes and the checked states of check-boxes, but I'm failing when trying to loop through the items in a list-box. Please see below for what I've tried...
When I click save:
Private Sub SaveToolStripMenuItem_Click(sender As Object, e As EventArgs)
Handles SaveToolStripMenuItem.Click
For Each i In ListBox1.Items()
My.Settings.ListBox1.Add(i)
Next
My.Settings.Save()
End Sub
When my form loads:
Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs)
Handles Me.Load
For Each i In My.Settings.ListBox1()
ListBox1.Items.Add(i)
Next
End Sub
I've only been using VB for three days, so apologies if I am missing something simple ha! Thanks for any help!!!
There is one small glitch with the StringCollection in settings. If you do not seed it with a fake variable then it starts out as Nothing and you cannot add to Nothing. in your form load add this:
' if the collection has not been initialized, do so
If My.Settings.ListBox1 Is Nothing Then
My.Settings.ListBox1= New System.Collections.Specialized.StringCollection
End If
' now it is safe to use: load strings from Setting -> form listbox
For Each s As String In My.Settings.ListBox1()
ListBox1.Items.Add(s)
Next
The very first time it runs, there are likely no saved settings, so we have to create the container for them, basically.
Option Strict can be implemented by file, by adding this at the top:
Option Strict On
Or for the project: Project => Properties => Compile: Option Strict is likely to the right (I have 2012). You can also set it as a permanent option (recommended).
Among other things, this will prevent you from plucking variables out of the air and use them without declaring a type (which will lead to errors). For instance:
For Each i In My.Settings.ListBox1()
becomes
For Each s As String In My.Settings.ListBox1() ' tell the compiler the Type
I have translated some code from C# to VB.net for the purpose of getting Folder Browser functionality. The link to the code is here.....
http://www.codeproject.com/KB/aspnet/DirectoryBrowsing.aspx
My issue is that I have not been able to correcly translate these two lines of code to VB.net.
TreeView1.TreeNodeExpanded +=new TreeNodeEventHandler(TreeView1_TreeNodeExpanded);
TreeView1.SelectedNodeChanged += new EventHandler(TreeView1_SelectedNodeChanged);
Every translator I have used has simply dropped the semicolon from the end of each line. But the editor still does not like them.
I could some help with this as it seems this effects the refresh of the selected folder in the tree view control.
I don't get to see the C drive folder unless I type the path in the text box, and the folder will still not expand.
thank you,
Use this:
AddHandler TreeView1.TreeNodeExpanded, AddressOf TreeView1_TreeNodeExpanded
AddHandler TreeView1.SelectedNodeChanged, AddressOf TreeView1_SelectedNodeChanged
Edit:
A different way to do this would be to apply it at the method level:
Protected Sub TreeView1_TreeNodeExpanded(ByVal sender as Object, ByVal e as TreeNodeEventArgs) Handles TreeView1.TreeNodeExpanded
' Some code
End Sub
Protected Sub TreeView1_SelectedNodeChanged(ByVal sender as Object, ByVal e as EventArgs) Handles TreeView1.SelectedNodeChanged
' Some code
End Sub
You should run this in debug to find out what exactly is going on. I find a lot of times when events of this nature are run in asp.net, you have a conflicting event that "resets" the controls you are attempting to change.