VB6 to VBNET Structure Problem

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tcomputerchip

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Ok this one may be difficault for some of you.


This is the problem. I have a converter program that converts binary data to text formated data. The class was written in VB6. I would like to convert the class to VBNET.

The problem is I don't know anything about Structures except that it replaces Type declerations.

Now, when I convert the Type over to structure I have many errors still in my dimentioned varialbles.

Example: VB6
Visual Basic: 
Type bLineData
    ByteOfData      As String * 1       '1 Char only
    LotsOfData(25)      As Byte         '25 bytes only
End Type

Change to VBNET:

Visual Basic: 
Structure bLineData
    Dim ByteOfData      As String * 1       'Not Working 
    Dim LotsOfData(25)    as Byte           'Not Working
End Structure



If someone could modify the code below, or parts of it and give me example of how I should convert the code to VBNET that would be great.

Code Working On:

Visual Basic: 
Module modConvert

Type LabelArea
    DateTimeValue(5) As Byte
    FileName            As String * 8   ' Redundent but here
    DeviceName          As String * 10  ' Name of part or part number
    Operator            As String * 10  ' Person that ran/collected test data
    TestingMode As Byte                 ' first bit 0 = TBB, 1 = TBS
    StationName         As String * 1   ' Station A,B,C,D and F
    LotName             As String * 10  ' Lot for device that were tested
    Comment             As String * 50  ' Comments of test
    TimePoint As Integer                ' Test number mostly for HiRel applications\
    SetQuantity As Integer              ' Number of device that were tested
    LoggingRate As Integer              ' Results sorted after N test 1 in 5, 2 in 10
    TestMax As Integer                  ' Number of test used to collect data
    DataBlockNum As Integer             ' Not used currently
    LoggedQuantity As Integer           ' Actual Logged quantity
    IndexMax As Integer                 ' Device Index
    Reserved(17) As Byte                ' Future use
End Type

Type TestItemArea
    TestNumber          As Byte         'Test Number
    ItemGroupCode       As Byte         'Item Group Code
    ItemCode            As Integer      'Item Code
    BEConditionFlag     As Byte         'BE Condition & Flag
    ResultBiasFlag      As Byte         'Result as BIAS Flag
    LimitItemName       As String * 6   'Limit Item Name
    LimitUnit           As Integer      'Limit Unit, second byte not used
    LimitValue          As Single       'Limit Value
    LimitMax            As Single       'Limit Min
    LimitMin            As Single       'Limit Max
    bias1Name           As String * 4   'Bias 1 Name
    bias1Unit           As String * 2   'Bias 1 Unit
    bias1Value          As Single       'Bias 1 Value
    bias2Name           As String * 4   'Bias 2 Name
    bias2Unit           As String * 2   'Bias 2 Unit
    bias2Value          As Single       'Bias 2 Value
    TimeCondition       As String * 4   'Time Condition Name
    TimeUnit(1)         As Byte         'Time Unit
    TimeValue           As Single       'Time Value
    DLIFlags            As Byte         'DL Inhibit Flags
    Reserved(6)         As Byte         'Reserved
End Type

Type WafferData
    wafferID         As Byte            'Always 'W'
    wafferNumber     As Byte            'Waffer Number
    NumberOfDevices  As Integer         'Number of devices
    Reserved         As Integer         'Reserved
End Type

Type DeviceData
    deviceID         As Byte            'Always 'D'
    ZeroZero         As Byte            'Always '00'
    SerialNumber     As Integer         'Number of devices
    BinNumber        As Integer         'Reserved
End Type

Type TestData
    TestNumber      As Byte             'TestNumber
    Flags           As Byte             'Flags
    TestValue       As Single           'Test Resualt Value
End Type

Type bLineData
    ByteOfData      As String * 1       'Extract data for check
End Type






End Module
 
All arrays dimensioned in VB.NET begin their indexes at zero, so
Dim LotsOfData(25) As Byte actually declares an array with a
length of 26.

Fixed-length strings are not supported in VB.NET, as you've
noticed. One way I could think of recreating this effect is an
array of Char variables, so LimitItemName As String * 6 would
change to LimitItemName(5) As Char, although I don't think it's
very efficient to convert between a Char array and a string when
you're changing the value of this variable. There may be another
way around this. If you stuck all these variables in a class, you
could trim the string in the Property accessor subs to ensure its
size does not exceed the maximum you want.

It's also worth noting that an Integer in VB6 is 16-bit, but an
Integer in VB.NET is 32-bit. In VB.NET, the 16-bit number variable
is Short. Bytes remain the same old 8 bits.

For more info, read the article "Upgrade Recommendation: Avoid
Arrays and Fixed-Length Strings in User-Defined Types" in the
help files.
 
Thanks for the reply. I know about the Integer problem, I have delt with that with several of the classes I have worked on.

The "LotsOfData(25) As Byte" does not work at all.
 
Ok, this is starting to get very frustrating. VB.NET is not VB6 at all. If you someone tells you different kick them in the shins!

This is the problem:

I need to read binary data from a file. In VB6 this is what it looked like:
Visual Basic: 
        Dim getLabelArea As LabelArea 'This is my Structure Code in VB6

'Open file code for binary omitted
            Get(FileInNum, getLabelArea, FileIndex)
            'This would take the Type and store the values read in binary mode into the Type Structure

This is VBNET
Visual Basic: 
            Seek(FileInNum, FileIndex)
            Input(FileInNum, getLabelArea) 'I need for getLabelArea to extract the data in the dimentioned order and store the data in the Difined Structure.

There maybe another way to read the data binary other than using the FileGet function. If there is where can I get some information or code on this?
 
Why not try serialization of classes? You can do that with XML or binary methods, to name two. The days of opening files, loading and parsing are gone, and so are the ones of relying on structures with fixed-length members, let the framework do the work for you.

I suggest XML Serialization as a great way to persist classes. It's saved me a boatload of work.
 
There is not too much documentation on the XML serialization. I only found 1 document that shows a sample. And it does not look like what I am trying to do.

If you could explain, or give sample code of this XML method, please do so.
 
I can't get fixed length arrays to work either, but you can get a fixed length string with this:

<vbfixedstring(x)> public StringName as string

where x is the number of letters

UPDATE:

Try using <vbfixedarray(x)> public ArrayName as whatever.
 
Last edited:
Update:

I have had no problem with the Top structure. The <VBFixedArray(6)> I knew about and was using.

To help in your troubleshooting, the section of the file that I am reading and having problems with is the LimitItemName; its stored as ASCII and is 6 char's long.

My problem is on the second Stucture when calling it through the file reader:

Visual Basic: 
'Module:
    Public Structure LabelArea
        Public DateYearTested As Byte
        Public DateMonthTested As Byte
        Public DateDayTested As Byte
        Public DateHourTested As Byte
        Public DateMinuteTested As Byte
        Public DateSecondTested As Byte
        <VBFixedString(8)> Public FileName As String            ' Redundent but here (8)
        <VBFixedString(10)> Public DeviceName As String         ' Name of part or part number (10)
        <VBFixedString(10)> Public Operator As String           ' Person that ran/collected test data (10)
        Public TestingMode As Byte                              ' first bit 0 = TBB, 1 = TBS (1)
        Public StationName As Char                              ' Station A,B,C,D and F (1)
        <VBFixedString(10)> Public LotName As String            ' Lot for device that were tested (10)
        <VBFixedString(50)> Public Comment As String            ' Comments of test (50)           
        Public TimePoint As Short ' Test number mostly for HiRel applications\
        Public SetQuantity As Short                            ' Number of device that were tested
        Public LoggingRate As Short                            ' Results sorted after N test 1 in 5, 2 in 10
        Public TestMax As Short                                ' Number of test used to collect data
        Public DataBlockNum As Short                          ' Not used currently
        Public LoggedQuantity As Short                         ' Actual Logged quantity
        Public IndexMax As Short                              ' Device Index
        <VBFixedArray(18)> Public Reserved As Byte              ' Future use (18)
    End Structure

    Public Structure TestItemArea
        Public TestNumber As Byte                               'Test Number
        Public ItemGroupCode As Byte                            'Item Group Code
        <VBFixedArray(2)> Public ItemCode As Byte                                'Item Code
        Public BEConditionFlag As Byte                          'BE Condition & Flag
        Public ResultBiasFlag As Byte                           'Result as BIAS Flag
        <VBFixedString(6)> Public LimitItemName As String       'Limit Item Name
        Public LimitUnit As Short                               'Limit Unit, second byte not used
        Public LimitValue As Single                             'Limit Value
        Public LimitMax As Single                               'Limit Min
        Public LimitMin As Single                               'Limit Max
        <VBFixedString(4)> Public bias1Name As String           'Bias 1 Name
        <VBFixedString(2)> Public bias1Unit As String           'Bias 1 Unit
        Public bias1Value As Single                             'Bias 1 Value
        <VBFixedString(4)> Public bias2Name As String            'Bias 2 Name
        <VBFixedString(2)> Public bias2Unit As String            'Bias 2 Unit
        Public bias2Value As Single                             'Bias 2 Value
        <VBFixedString(4)> Public TimeCondition As String       'Time Condition Name (4)
        <VBFixedString(2)> Public TimeUnit As Byte               'Time Unit (2)
        Public TimeValue As Single                              'Time Value
        Public DLIFlags As Byte                                 'DL Inhibit Flags
        <VBFixedArray(7)> Public Reserved As Byte               'Reserved
    End Structure


This is a stripped down version of what I am doing, the section of code that I am having problems with is noteded below.
Visual Basic: 
Function ConvertFile() As Boolean

'...Inside class function

                FileIndex = 1
                FileGet(FileNum, getLabelArea, FileIndex) ', FileIndex)
                FileIndex = FileIndex + 127

'...Removed Company code...

'...Continue Public code...

                    For i = 1 To getLabelArea.TestMax
                        FileGet(FileNum, getTestItemArea, FileIndex)


                        TestItemL1 = TestItemArea.LimitItemName.ToString  'Always returns 0, not wanted, should return String of Text (6 chr's long)
                        FileIndex = (i * 64) + 128
                    Next i
'...End Public code...
End Function
 
Hi, I am having problems with using VBFixedArray's.

I am declaring it like so:

<VBFixedArray(MaxSize)> Dim myArray() as String

but when I go to initialize all the indices like so:

For i=0 to MaxSize-1
Template.myArray(i) = ""
Next i

I get an error "Object reference not set to an instance of an object"

My template is set up as follows:

<code>

Structure TemplateType
...
<VBFixedArray(MaxSize)> Dim myArray() as String
...
Public Sub Initialize()
ReDim myArray(MaxSize)
End Sub
End Structure

Public Template As TemplateType

Public Function InitializeTemplate() as Object
...
For i = 0 to MaxSize-1
Template.myArray(i) = ""
'The line above fails
Next i
...
End Function

</code>

Please help as I have sadly been trying to figure this out for a good 10+ hours.

Thank you
ip
 
Forget it, problem solved.

This was originally a vb6 that i upgraded to .net and it created a initialize function that redim'd myArray, but the initialize function was never actually called, so i just through a call to it in my initialize template function before i started setting myarray(i) equal to anything.

Arg, the relief of finding such a simple solution after ragging my brains out for 10+ hours.
 
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