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Miscellaneous

   Easy Can I send keystokes to a dos app?

   Easy Can I compile 16 bit apps in VB5?

   Medium How can I check to see if a certain switch has been passed on the command line?

   Medium What does an "Out of Stack space" error message mean?

   Medium I have a VB application that loads improperly. Some of the controls and text boxes are white when the application loads until the form_load procedure is complete.

   Medium I process customer orders, and they come in batches of tens. I need to round a number to the closest 10, but I can only round up. Otherwise, the user won't have sufficent product. How can I do this? Plus, is there anyway to round down?

Can I send keystokes to a dos app?

Compatibility:VB3 VB4 VB5

It is possible to use DOS redirection commands to do that with some apps. For instance, to format your diskdrive, print "Y"(no quotes) to a file name "myfile.txt". Then do this:

shell "format a: < myfile.txt"

Tada!

Can I compile 16 bit apps in VB5?

Compatibility:VB3 VB4 VB5

No.

How can I check to see if a certain switch has been passed on the command line?

Compatibility:VB3 VB4 VB5

Use this function:

Function GetCommandLine(iMaxArgs As Integer, iArgCnt As Integer)

    Dim i As Integer
    Dim iCmdLnLen As Integer
    Dim iNumArgs As Integer

    Dim fInArg As Boolean

    Dim cArg As Variant
    Dim CmdLine As Variant

    If IsMissing(iMaxArgs) Then iMaxArgs = 10

    ReDim ArgArray(iMaxArgs)

    iNumArgs = 0: fInArg = False

    CmdLine = Command()
    iCmdLnLen = Len(CmdLine)

    For i = 1 To iCmdLnLen
        cArg = Mid(CmdLine, i, 1)
        If (cArg <> " " And cArg <> vbTab) Then
            'Neither space nor tab.
            'Test if already in argument.
            If Not bInArg Then
            'New argument begins.
            'Test for too many arguments.
                If iNumArgs >= iMaxArgs Then Exit For
                iNumArgs = iNumArgs + 1
                fInArg = True
            End If
            'Concatenate character to current argument.
            ArgArray(iNumArgs) = ArgArray(iNumArgs) & cArg
        Else
            'Found a space or tab.
            bInArg = False
        End If
    Next i

    'Resize array just enough to hold arguments.
    ReDim Preserve ArgArray(iNumArgs)

    iArgCnt = iNumArgs
    GetCommandLine = ArgArray()

End Function 
 

What does an "Out of Stack space" error message mean?

Compatibility:VB3
 VB4
 VB5
That means your code in stuck in a infinite loop. For instance, this code will produce that error: 

sub badSub()
	badSub
end sub


Another, somewhat more subtle example, is if you put this code in a text boxes change event:

text1 = reverse(text1)


(Assuming, of course, you wrote a function to reverse a string named reverse.) When you assign the reverse of text1 to text1, you cause text1_change to fire again. And again. And again. 
 
 

 I have a VB application that loads improperly.  Some of the
  controls and text boxes are white when the application loads until the
  form_load procedure is complete. 



Compatibility:VB3
 VB4
 VB5
You need to put some DoEvents statements in your code. Your Form_Load procedure is usurping the CPU time, and DoEvents give Windows a chance to repaint and process window messages.
 
 

I process customer orders, and they come
in batches of tens. I need to round a number to the closest
10, but I can only round up. Otherwise,
the user won't have sufficent product. How can I do this? Plus, is there anyway to round down?

Compatibility:VB3
 VB4
 VB5
Use these functions:

Function RoundUp(byVal Value as long, Round as long)
       RoundUp = ((Value \ Round) + Sgn(Value Mod Round)) * 5
End Function

Function RoundDown(byVal Value as long, Round as long)
       RoundUp = Value  -  (Value mod Round)
End Function
 
 









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