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I am trying to write a simple WPF application in VB using Vs2010 and SQLExpress 2012, although i am not using any databinding.
The problem is that although i have found lots of examples of how to write code to read data from the database, some of it seems very complex and others real simple.
Now i want to update my DB and add (transaction log) records to it, i cannot find an example that works with my current setup. It can't be that difficult can it?
Class MainWindow
Dim dataEntities As MaxGateEntities = New MaxGateEntities
Dim passno As String
Dim passcnt As Integer
Dim inout As String
Private Sub Enter_Button_Click(sender As System.Object, e As System.Windows.RoutedEventArgs)
Dim Passes As ObjectQuery(Of Pass) = dataEntities.Passes
Dim PassTransactions As ObjectQuery(Of Transaction) = dataEntities.Transactions
passno = Me.PassNumber.Text
Dim passQry = From pass In Passes Where pass.PassID = passno Select pass.InOut
passcnt = passQry.Count
For Each item In passQry
inout = item.ToString
Next
End Sub
End Class
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Gerald Connolly wrote: It can't be that difficult can it?
Depends on what you consider to be difficult. There are examples on MSDN that use adapters, but most of the time you'll see UPDATE or INSERT statements. The example for LINQ can be found here[^].
Bastard Programmer from Hell 
if you can't read my code, try converting it here[^]
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Eddy,
I have seen that page, but the examples have this line?
Dim db As New Northwnd("…\Northwnd.mdf")
and i don't have one of those. I added a data source using ADO entities and included the appropriate statement as in my code.
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Gerald Connolly wrote: I added a data source using ADO entities and included the appropriate statement as in my code.
That's a wizard that generates code, and I have not worked with the ADO.NET Entities; the documentation is not very helpful either. That's the reason why I'm still using old-fashioned Sql and simple IDbCommands.
I found an example that matches your code here[^], but I haven't succeeded yet in creating a simple console-application that performs an insert.
Bastard Programmer from Hell
if you can't read my code, try converting it here[^]
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I'm a novice programmer. I am having problem in connecting a printer "DATECS DPP-250" in my code. I tried to add "PrintDriver.dll"
but it output's like there is some kind of error that THE memory is being corrupted. I've searched a lot forums but still I can't solve it. Please I really need all of your help.
THIS IS THE PROBLEM:
_________________________________________________________
See the end of this message for details on invoking
just-in-time (JIT) debugging instead of this dialog box.
************** Exception Text **************
System.AccessViolationException: Attempted to read or write protected memory. This is often an indication that other memory is corrupt.
at PrintDriverNet.Printer.PDSDK_OpenPrinter(Int32 nKernelMode, String strPrinterName)
at PrintDriverNet.Printer.OpenPrinter() in d:\Sources\Projects\Datecs\PrinterUtility\PrintDriverNet\PrintDriverNet.cs:line 471
at Testing.MainForm.buttonRead_Click(Object sender, EventArgs e) in D:\Works\Testing\Testing\MainForm.vb:line 44
at System.Windows.Forms.Control.OnClick(EventArgs e)
at System.Windows.Forms.Button.OnClick(EventArgs e)
at System.Windows.Forms.Button.OnMouseUp(MouseEventArgs mevent)
at System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks)
at System.Windows.Forms.Control.WndProc(Message& m)
at System.Windows.Forms.ButtonBase.WndProc(Message& m)
at System.Windows.Forms.Button.WndProc(Message& m)
at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)
************** Loaded Assemblies **************
mscorlib
Assembly Version: 2.0.0.0
Win32 Version: 2.0.50727.4927 (NetFXspW7.050727-4900)
CodeBase: file:///C:/Windows/Microsoft.NET/Framework/v2.0.50727/mscorlib.dll
----------------------------------------
Testing
Assembly Version: 1.0.0.0
Win32 Version: 1.0.0.0
CodeBase: file:///D:/Works/Testing/Testing/bin/Debug/Testing.exe
----------------------------------------
Microsoft.VisualBasic
Assembly Version: 8.0.0.0
Win32 Version: 8.0.50727.4927 (NetFXspW7.050727-4900)
CodeBase: file:///C:/Windows/assembly/GAC_MSIL/Microsoft.VisualBasic/8.0.0.0__b03f5f7f11d50a3a/Microsoft.VisualBasic.dll
----------------------------------------
System
Assembly Version: 2.0.0.0
Win32 Version: 2.0.50727.4927 (NetFXspW7.050727-4900)
CodeBase: file:///C:/Windows/assembly/GAC_MSIL/System/2.0.0.0__b77a5c561934e089/System.dll
----------------------------------------
System.Windows.Forms
Assembly Version: 2.0.0.0
Win32 Version: 2.0.50727.4927 (NetFXspW7.050727-4900)
CodeBase: file:///C:/Windows/assembly/GAC_MSIL/System.Windows.Forms/2.0.0.0__b77a5c561934e089/System.Windows.Forms.dll
----------------------------------------
System.Drawing
Assembly Version: 2.0.0.0
Win32 Version: 2.0.50727.4927 (NetFXspW7.050727-4900)
CodeBase: file:///C:/Windows/assembly/GAC_MSIL/System.Drawing/2.0.0.0__b03f5f7f11d50a3a/System.Drawing.dll
----------------------------------------
System.Configuration
Assembly Version: 2.0.0.0
Win32 Version: 2.0.50727.4927 (NetFXspW7.050727-4900)
CodeBase: file:///C:/Windows/assembly/GAC_MSIL/System.Configuration/2.0.0.0__b03f5f7f11d50a3a/System.Configuration.dll
----------------------------------------
System.Xml
Assembly Version: 2.0.0.0
Win32 Version: 2.0.50727.4927 (NetFXspW7.050727-4900)
CodeBase: file:///C:/Windows/assembly/GAC_MSIL/System.Xml/2.0.0.0__b77a5c561934e089/System.Xml.dll
----------------------------------------
System.Runtime.Remoting
Assembly Version: 2.0.0.0
Win32 Version: 2.0.50727.4927 (NetFXspW7.050727-4900)
CodeBase: file:///C:/Windows/assembly/GAC_MSIL/System.Runtime.Remoting/2.0.0.0__b77a5c561934e089/System.Runtime.Remoting.dll
----------------------------------------
PrintDriverNet
Assembly Version: 1.0.4652.23888
Win32 Version: 1.0.4652.23888
CodeBase: file:///D:/Works/Testing/Testing/bin/Debug/PrintDriverNet.DLL
----------------------------------------
************** JIT Debugging **************
To enable just-in-time (JIT) debugging, the .config file for this
application or computer (machine.config) must have the
jitDebugging value set in the system.windows.forms section.
The application must also be compiled with debugging
enabled.
For example:
<configuration>
<system.windows.forms jitdebugging="true">
When JIT debugging is enabled, any unhandled exception
will be sent to the JIT debugger registered on the computer
rather than be handled by this dialog box.
___________________________________________________________
AND HERE IS MY CODE:
__________________________________________________________
Imports PrintDriverNet
Public Class Form1
Private Sub buttonRead_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles buttonRead.Click
Dim printer__1 As New Printer()
Dim msr_params As Integer = Printer.MRPARAM_PREFIX
Dim buffer As Byte() = New Byte(256 * 3 - 1) {}
Dim res As Integer
textBoxTrack1.Text = String.Empty
textBoxTrack1.Update()
textBoxTrack2.Text = String.Empty
textBoxTrack2.Update()
textBoxTrack3.Text = String.Empty
textBoxTrack3.Update()
Try
textBoxTrack1.Text = "Connecting ..."
textBoxTrack1.Update()
textBoxTrack2.Text = "Connecting ..."
textBoxTrack2.Update()
textBoxTrack3.Text = "Connecting ..."
textBoxTrack3.Update()
''-----I can't connect to my printer here in this statement,it crashes
*--> If printer__1.OpenPrinter() < 0 Then
Throw New ApplicationException("Failed to open connection with printer.")
End If
.------''
textBoxTrack1.Text = "Swipe a magnetic card ..."
textBoxTrack1.Update()
textBoxTrack2.Text = "Swipe a magnetic card ..."
textBoxTrack2.Update()
textBoxTrack3.Text = "Swipe a magnetic card ..."
textBoxTrack3.Update()
If checkBoxTrack1.Checked Then
msr_params = msr_params Or Printer.MRPARAM_TRACK1
End If
If checkBoxTrack2.Checked Then
msr_params = msr_params Or Printer.MRPARAM_TRACK2
End If
If checkBoxTrack3.Checked Then
msr_params = msr_params Or Printer.MRPARAM_TRACK3
End If
If (InlineAssignHelper(res, printer__1.ReadMagstripe(10000, msr_params, buffer, buffer.Length))) < 0 Then
Throw New ApplicationException("Failed to read magstripe data.")
End If
textBoxTrack1.Text = "No track selected or available data."
textBoxTrack2.Text = "No track selected or available data."
textBoxTrack3.Text = "No track selected or available data."
Dim i As Integer = 0, j As Integer = -1
While i < res
Select Case buffer(i)
Case &HF1
j = buffer(i)
textBoxTrack1.Text = String.Empty
Exit Select
Case &HF2
j = buffer(i)
textBoxTrack2.Text = String.Empty
Exit Select
Case &HF3
j = buffer(i)
textBoxTrack3.Text = String.Empty
Exit Select
Case Else
Select Case j
Case &HF1
textBoxTrack1.Text += Convert.ToChar(buffer(i))
Exit Select
Case &HF2
textBoxTrack2.Text += Convert.ToChar(buffer(i))
Exit Select
Case &HF3
textBoxTrack3.Text += Convert.ToChar(buffer(i))
Exit Select
End Select
Exit Select
End Select
i += 1
End While
If checkBoxOnPaper.Checked Then
Dim receipt As String = String.Empty
receipt += vbLf
receipt += "Track1: " & textBoxTrack1.Text & vbLf
receipt += "Track2: " & textBoxTrack2.Text & vbLf
receipt += "Track3: " & textBoxTrack3.Text & vbLf
receipt += vbLf & vbLf & vbLf
Dim printBuff As Byte() = System.Text.Encoding.ASCII.GetBytes(receipt)
If printer__1.WritePrinterDirect(printBuff, printBuff.Length) < 0 Then
Throw New ApplicationException("Failed to print data.")
End If
End If
If printer__1.ClosePrinter() < 0 Then
Throw New ApplicationException("Failed to close connection with printer.")
End If
Catch ae As ApplicationException
textBoxTrack1.Text = ae.Message
textBoxTrack2.Text = ae.Message
textBoxTrack3.Text = ae.Message
Finally
printer__1.Dispose()
End Try
End Sub
Private Shared Function InlineAssignHelper(Of T)(ByRef target As T, ByVal value As T) As T
target = value
Return value
End Function
End Class
__________________________________________________________
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What exactly do you mean by "connecting a printer"??
What version of Windows are you running this app on? 32 or 64 bit? Is your app compiled to target AnyCPU, or x86 or x64?? What bitness is the library you're using?
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I mean it's opening port so my code can pass through.
My problem when it goes through this statement, It says that the memory is corrupt because of the "PrintDriver.dll."
___________________________________________________________
If printer__1.OpenPrinter() < 0 Then
Throw New ApplicationException("Failed to open connection with printer.")
End If
___________________________________________________________
Im using 32bit and x86 compilation. Please,If you have an email, I can pass it to you about my program because I can't explain briefly here. So you can see what I mean sir. 
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You don't need my email.
You also need to contact whoever wrote that .DLL you're using. I've never used it and never heard of it. You've got a specific problem with a third party product. You're best source of information on that problem is whoever wrote the product.
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I see sir..You've got a point. Thank you for your advice sir Dave..
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How is that PrintDriver.dll used - are there COM objects, or do you need DllImport/Declare statements? In the latter case, I'd say that the Marshalling of some types was not correct.
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Hi,
I am accessing App.Major App.Minor in my VB6 application. And my O.S is Windows 7. When i am running this application from "administrator" user application is working fine and these variables are getting accessed. However, when logging to local limited rights user we are getting the error:
Run –time error “326”, Resource with identifier “VERSION” not found”.
So kindly suggest what should we need to do on our Win 7 systems to fix this?
Regards,
Dipesh
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Member 4512356 wrote: So kindly suggest what should we need to do on our Win 7 systems to fix this?
It's not the Win7 system that is "broken", but your programming platform. VB6-support is non-existing.
If you wanna use a modern OS, then the best idea is to do so using a modern language.
Bastard Programmer from Hell
if you can't read my code, try converting it here[^]
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Locate the executable in Windows Explorer, open the Properties window, then the Compatibilty tab. There, select an appropriate version in the "Run with compatibilty mode" combobox. Do not forget the "Change for all users" button.
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Hi,
Thanks for your reply. It did half of the work. After doing these settings i was able to execute my application from normal user account. But as soon as i log into "administrator" user and then try to log back to normal user the error again occurs. That is the problem re occurs after switching to administrator and back. The settings were there but it just stopped working! And even if i redo these settings the problem persists. So, can you suggest some other settings.
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Hi All,
I finally got solution of this issue myself. My application was having a code where I was impersonating a admin user and then doing some stuff. On debugging more i found that my application was not running beyond the point where i was passing token of impersonation to next command. Then i changed the security policy of my Win 7 system and added my user in following security policy "create token" something.. and this resolved my issue. 
Hope it will be useful for somebody.
Regards,
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I have following problem in my VB6 project:
I have an array of 44 bytes, aTZI(), which is a result of WMI objRegistry.GetBinaryValue call.
I also have defined a user types and a variable:
Public Type SYSTEMTIME
wYear As Integer
wMonth As Integer
wDayOfWeek As Integer
wDay As Integer
wHour As Integer
wMinute As Integer
wSecond As Integer
wMilliseconds As Integer
End Type
Public Type TIME_ZONE_INFORMATION
Bias As Long
StandardName(0 To 63) As Byte
StandardDate As SYSTEMTIME
StandardBias As Long
DaylightName(0 To 63) As Byte
DaylightDate As SYSTEMTIME
DaylightBias As Long
End Type
Public zoneTZI As TIME_ZONE_INFORMATION
How can I get aTZI into zoneTZI, so that I can read each element of the TIME_ZONE_INFORMATION?
Whatever I try to do gets me an error "Only user-defined in public object modues can be coerced to or from a variant pr passed to late-bound functions"
Every suggestion will be appreciated.
Thanks!
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Member 9539647 wrote: Every suggestion will be appreciated.
Use .NET to implement the functionality, and call it from your VB6 application.
It's not recommended to write new functionality in a deprecated language; as you already found out, support is growing thinner and will eventually disappear. You can use the VB6 Interop Toolkit to slowly migrate parts of your code to the new platform.
Bastard Programmer from Hell
if you can't read my code, try converting it here[^]
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Hello all , i'm learining VB.NET and have some questions. will you please helping me by answer them. 1- what the syntax can be used to query Entity framwork collections? is it Lambda function or LINQ expressions. 2- which vb concept is used to add extra methods that can applied to a class without use of inheritance? is it Anonymous classes or implicit typing or Nullable types or Extension methods.3- in ASP.NET ther is data-access layer created how to write a method that returns several objects to used in UI layer.
I apprecitate any help
Thank you so much and best regards
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Smells like homework, since the answers are included in the question. The value of the question is in your research, not the correct answers; the idea is that you'd spend time on researching each of the unknowns in the question and get exposed to new knowledge.
khalid333 wrote: 1- what the syntax can be used to query Entity framwork collections? is it Lambda function or LINQ expressions.
After Googeling for "syntax ef framework", I'd vote for a LINQ expression.
khalid333 wrote: 2- which vb concept is used to add extra methods that can applied to a class without use of inheritance? is it Anonymous classes or implicit typing or Nullable types or Extension methods.
Extension methods.
Again, the answer is a bit useless - the idea is that you learn to differentiate between those items (and get to know them) so you can answer the question once your confronted with it during work: should you use an Nullable Type? Implicit Typing? What should you code when a coworker says that you'll need an "extension method"?
khalid333 wrote: <layer>.3- in ASP.NET ther is data-access layer created how to write a method that returns several objects to used in UI layer.
Same way as we pass EventArgs; you'd create a base-class that encapsulates the result-objects and return that. If you'd rather use a struct, that's possible too - but then I'd additionally recommend to make it a immutable struct.
Bastard Programmer from Hell
if you can't read my code, try converting it here[^]
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Thank you so much Eddy for your kind help .
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Hi everyone out there
I have a problem (in the VERY beginning state) of writing a VB.NET DLL that will be used as a plugin for a C++ Program.
I try to outline what the goal is...
There is a videochat program called CamFrog. For this a Bot (for managing the chatroom) is available that uses plugins. The Bot comes with a C++ sample for a simple plugin. What i want to do is to "translate" that into a VB.NET Version (because C++ is really not my thing... i hardly figured out how the sample might work).
Now... I know that a .NET DLL is not the same as the C++ DLLs that are used by the bot but i guess it should be possible to achieve the same with COM Interop... I hope I'm right.
Now I looked on the sample plugin with dependency walker and it exports a few functions that will be called by the bot-program.
My first step now is to try to build a dll in VB.NET (2010 express) that ecports one simple function... i just want to see the function in dependency walker for now.
What i did so far:
I followed the guide from MS (Walkthrough: Creating COM Objects with Visual Basic[^]) using the part "Creating COM Objects without the COM Class Template
" (and some other hints from different pages i found). All settings are ok as far as i can see and my "code" is as follows:
Imports System.Runtime.InteropServices
<ComClass(ComClass1.ClassId, ComClass1.InterfaceId, ComClass1.EventsId)> _
Public Class ComClass1
Public Const ClassId As String = "C4889882-ECC6-4BBE-9B65-A9DCC30B90F8"
Public Const InterfaceId As String = "6420CC9C-2B69-4DFD-A149-C694895D80BD"
Public Const EventsId As String = "0A0ACD71-7651-4BE5-9128-FE8AECCAE623"
Public Sub New()
MyBase.New()
End Sub
<ComVisible(True)> _
Public Function testfunction() As Boolean
Return True
End Function
End Class
As far as I understood "testfunction" should now be visible as an exported function of the DLL in dependency walker...
But... it doesn't appear (list of exported functions is empty).
The whole thing with COM-Interop and that stuff is completely new for me and I barely understood all the things I read during the last 5 or 6 hours googling... so I'm sure that I miss something on it.
I hope someone can kick me in the right direction.
Thanks in advance
-obi-
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Does the example provided by the manufacturer use COM? Well, then your idea of COM interop will be feasable.
Otherwise you should know that C++ does not mean COM! If the interface is defined with C++ header files (*.h), then you'll have to write a mixed mode (managed + unmanaged) dll in C++ which in turn can call your VB.Net dll. That is possible, but not at all easy when you do not yet understand the concepts.
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Bernhard Hiller wrote: Otherwise you should know that C++ does not mean COM!
I knew it sounded to easy to me...
Bernhard Hiller wrote: If the interface is defined with C++ header files (*.h), then you'll have to write a mixed mode (managed + unmanaged) dll in C++ which in turn can call your VB.Net dll
There is a bunch of header files... but I have no idea how to do this "wrapper dll" in c++... also it's neccessary that my dll in turn calls functions of the c++ program (or it's dlls).
Would it be possible to do what i want using VB6 instead of vb.net? In the documentation they mentioned (in one sentence) Visual Basic and Delphi as possible languages.
I never used VB6 before (stopped using VB at VB3 and restarted with VB.NET 2010) but i think that will be much easier for me than learning C++ from scratch.
Anyway thanks for your answer Bernhard... even if I'm not really happy with my new knowledge 
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hello -
am trying to open and/or read a large csv file in VB, then write it to a txt file, starting with the 2nd line. i can open the csv, but cant seem to read (getting "past end of file" error) or write it. can manually open it in notepad and save it, then open/read THAT file, but defeats the purpose.... ideas, suggestions? thnx!
dubscat
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Post some code and the folks here will be able to help you out.
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