Logic Flow Problem, Please help tearing my hair out!

[jlegan]

This is a flow issue.

Ok, going try to explain this as best I can.

Right now what my program does is takes items that are checked in a Checked List Box and compares them to a specific registry key. Currently everything is working great however there are times that a driver might be installed on a system and there are no printer objects associated with it in which case I want to state so in the txtLog. However if you follow the logic below you will see what I am running into (Yes I am a beginner VB programmer). What happens is in the For Each statement is that the txtLog is overrun with the text from the Else statement because it is doing it For Each.

IE: In otherwords if I have 1 item selected in the listbox it checks all 3 of the printers installed against the currently installed drivers and comes back with:

Not in Use
Not in Use
Found It!

If I take out the else statement then all is well however there are times when someone might select an item in the listbox that does not have a printer associated with it in which case I would like for them to know what is going on.
Thanks.

Jim

Dim prnCount As Integer
        Dim strPrinter As String
        Dim strlbText
        Dim strDriver
        envstrOS = Shell.ExpandEnvironmentStrings("%COMPUTERNAME%")
        ' LISTS ALL OF THE PRINTER OBJECTS INSTALLED ON THE SYSTEM.
        Dim RegKey As RegistryKey = Registry.LocalMachine.CreateSubKey( _
        "SYSTEM\CurrentControlSet\Control\Print\Printers")
        Dim SubKeys() As String = RegKey.GetSubKeyNames()
        ' GOES THROUGH THE LIST OF PRINTERS ONE AT A TIME
        If SubKeys.Length > 0 Then
            For prnCount = 0 To SubKeys.Length - 1
                strPrinter = (SubKeys(prnCount))
                ' QUERIES THE REGISTRY KEY "PRINTER DRIVER" TO DETERMINE WHAT DRIVER A PRINTER OBJECT USERS.
                Dim DrvRegKey As RegistryKey = Registry.LocalMachine.OpenSubKey( _
                "SYSTEM\CurrentControlSet\Control\Print\Printers\" & strPrinter)
                Dim objPrinterDriver As Object = DrvRegKey.GetValue("Printer Driver")
                ' CHECKS AGAINST A CHECKED LISTBOX TO SEE IF ANY OF THE ITEMS CHECKED MATCH THE PRINTER DRIVER FOUND ABOVE
                For Each strDriver In lbDrivers.CheckedItems
                    If strDriver = objPrinterDriver Then
                        txtLog.AppendText(strPrinter & " uses " & strDriver)
                        txtCombined.AppendText("\\" & envstrOS & "\" & strPrinter & "," & "\\" _
                        & envstrOS & "\" & strPrinter & ControlChars.CrLf)
                    Else
                        ' --- HERE IS THE PROBLEM, WITH THE ELSE STATEMENT ---
                        txtLog.AppendText("Driver " & strDriver & " is not in use by any printer object")
                    End If
                Next
            Next prnCount
 
        End If

[hellswraith]

You can use an ArrayList, then just add items to it as it is going. Then when you are done, write the contents of the array list to the log.

[jlegan]

I hate to as but could you help with out with the syntax of that, I am actually learning through writting these utilities.

Thanks,

Jim

[hellswraith]

I am sorry, my first post was under a different assumption. I thought you were writing to a log file. You are only writing to a text box, is this correct? I don't understand what is going on. There shouldn't be a problem adding more text to the text box, whether it is in the first part of an if, or the else clause.

If it is a small project, you can zip it and post it here, I will look at the whole thing. I am having problems understanding exactly what it is supposed to do.

[jlegan]

I attached the project in the next post:

The situation is:

The code as listed above works great, however.....

Right Here:

For Each strDriver In lbDrivers.CheckedItems
                    If strDriver = objPrinterDriver Then
                        txtLog.AppendText(strPrinter & " uses " & strDriver)
                        txtCombined.AppendText("\\" & envstrOS & "\" & strPrinter & "," & "\\" _
                        & envstrOS & "\" & strPrinter & ControlChars.CrLf)
                    Else
                        ' --- HERE IS THE PROBLEM, WITH THE ELSE STATEMENT ---
                        txtLog.AppendText("Driver " & strDriver & " is not in use by any printer object")
                    End If
                Next

Where it says --- HERE IS THE PROBLEM, WITH THE ELSE STATEMENT --- here is what happens.

In the:

If strDriver = objPrinterDriver Then

It goes through the For Each items checked in the CheckedListBox section and if there is a match it outputs to the two text boxes. This works great. However what I wanted to do was put a little bit of information in there If what they had selected in the CheckListBox did not have a match the just to append that to the text box. However what I am running into is that if the For Each (there are two "FOR" statements if you look at the code above) loop runs 50 times and there is only 1 match then I am getting that one match in the text box and 49 Not Matched.

So if for example if Jim is the only item checked in the CheckListBox and there are a list of 100 names in the For Each loop then I would get 99 NOT Matched and 1 matched all appened to the text file.

I want it so it only appends if it is not matched and only once, not each time the loop runs.

I hope that made it more clear. If you still need to post it let me know and I will put it up there.

Thanks,

Jim

[jlegan]

Attached is the project.

[hellswraith]

Try this... This is what I think you are trying to do:

Private Sub GenerateFiles()
        Dim prnCount As Integer
        Dim strPrinter As String
        Dim strlbText
        Dim strDriver
 
        envstrOS = Shell.ExpandEnvironmentStrings("%COMPUTERNAME%")
 
        ' LISTS ALL OF THE PRINTER OBJECTS INSTALLED ON THE SYSTEM.
        Dim RegKey As RegistryKey = Registry.LocalMachine.CreateSubKey( _
                "SYSTEM\CurrentControlSet\Control\Print\Printers")
 
        Dim SubKeys() As String = RegKey.GetSubKeyNames()
 
        ' GOES THROUGH THE LIST OF PRINTERS ONE AT A TIME
        If SubKeys.Length > 0 Then
 
            For prnCount = 0 To SubKeys.Length - 1
                strPrinter = (SubKeys(prnCount))
 
                ' QUERIES THE REGISTRY KEY "PRINTER DRIVER" TO DETERMINE WHAT DRIVER A PRINTER OBJECT USERS.
                Dim DrvRegKey As RegistryKey = Registry.LocalMachine.OpenSubKey( _
                                "SYSTEM\CurrentControlSet\Control\Print\Printers\" & strPrinter)
                Dim objPrinterDriver As Object = DrvRegKey.GetValue("Printer Driver")
 
                ' This will hold the value to tell if the driver was found in the checked items.
                Dim foundOne As Boolean = False
 
                ' CHECKS AGAINST A CHECKED LISTBOX TO SEE IF ANY OF THE ITEMS CHECKED MATCH THE PRINTER DRIVER FOUND ABOVE
                For Each strDriver In lbDrivers.CheckedItems
 
                    If strDriver = objPrinterDriver Then
                        txtLog.AppendText(strPrinter & " uses " & strDriver & ControlChars.CrLf)
                        txtCombined.AppendText("\\" & envstrOS & "\" & strPrinter & "," & "\\" _
                        & envstrOS & "\" & strPrinter & ControlChars.CrLf)
 
                        ' We found one, now we set the variable to true.
                        foundOne = True
                    End If
                Next
 
                'Check after that loop if one was found.  If none were found
                'The foundOne variable will still be false.  So if it is false,
                'need to append a message saying it isn't in there.
                If foundOne = False Then
                    txtLog.AppendText("Driver " & objPrinterDriver & " is not in use by any printer object" & ControlChars.CrLf)
                End If
 
            Next prnCount
        End If
    End Sub

[jlegan]

If you have at least two printers installed on your system run the program and hit Generate List. Once you see all of the printer drivers installed on your system select one of them and click Generate List File.

You will see output that looks like this:

Driver "Xerox DocuPrint P1210" is not in use by any printer object
"P1210" uses "Xerox DocuPrint P1210"

In this case P1210 is the name of the Printer Object in the Printers Windows (Start > Settings > Printers) and "Xerox DocuPrint P1210" is the name of the driver installed for it. However since it goes thru a "For" statement for each driver on the system (ie why you need more than one printer installed to see the issue) then you will get the syntax listed above which inaccurately says that the driver is not in use by any printer object and then while doing the For loop it finally reaches and match and writes the proper data, stating which printer object uses that driver.

What I am trying to do is only get the "Driver XXXXXXX is not in use by any printer object" in the txtLog if there are no matches, somehow delaying that Append to that box until after the For loop completes that round of searching and before moving onto the next.

The code you provided is what I came up with today after a few hours of toying around but still ran into the problem above.

If you could offer a little more guidence I would appreciate it, I know I was close earlier but I am just missing that final piece.

Thanks as always,

Jim

[hellswraith]

I will have to look at it tomorrow, my mind is becoming shot right now, and I still have some stuff to solve in my own app. I will take a look at it tomorrow when I have fresh eyes.

Also, I am working from a laptop that doesn't have any printers or drivers installed, so it is kind of hard to test it. Talk to you later about it, k.

[jlegan]

Anyone have any other thoughts on this?

[jlegan]

This is the last time I will write in on this issue. If anyone has any advice I would appreciate it. This is the only thing that is preventing me from finishing this program.

Thanks,

Jim