Meaning of the code - visual basic 6 class file - vb6

What's the meaning of below line of code?
Public Sub Update( _
Optional ByVal astrJDE_SUPPLIER_ID As String = MISSING_STRING, _
)
What is the meaning of 'MISSING_STRING'? OR is this user-defined variable?

MISSING_STRING is user defined constant

Related

Declaring VB6 DLL Functions with two Dimensional Array

I have these arrays:
Dim sInp(10) As String
Dim dInp(90) As Double
Dim sOut(500, 10) As String
Dim dOut(500, 100) As Double
Now I have to declare the following function:
Integer MyFunction(sInp, dInp, dOut, sOut)
How do I do that?
So far I have this Code:
Declare Function MyFunction Lib "C:\Path\To\My\dll.dll" (ByRef sInp() As String, ByRef dInp() As Double, ByRef dOut() As Double, ByRef sOut() As String): Integer
How do I make the last two params to multidimensional arrays?
I already did register the library and the IDE can find the function but I can't use it so I thought I have to declare it like this.
This is all of the documentation I got from the company:
Integer MyFunction(sInp, dInp, dOut, sOut )
sInp[10] (string type)
dInp[90] (double type)
sOut[500, 10] (string type) (The String are initialized as “”)
dOut[500, 100] (double type) (The value are initialized as -9999.99 )
If you say you registered the DLL with "regsvr32" and got a success message then it is an ActiveX DLL (a COM object) and as such you need to instantiate it as you do with any object. First you need to click Project -> References, look for the name of your DLL in the list and click the checkmark beside it. Then you can declare instances from it:
Dim ObjDLL as New WhateverTheDLLClassIsCalled
Then it should expose the "MyFunction" method and you should see its parameters:
Call ObjDll.MyFunction()
The "Declare Function MyFunction Lib" syntax is for regular DLLs that do not need to be registered.

Using Nim to Creating a vb6 dll that Returns String

Nim Compiler Version 1.6.6 [Windows: i386]
Compiled at 2022-05-05
Copyright (c) 2006-2021 by Andreas Rumpf
active boot switches: -d:release
Cmd Compile
nim c --cpu:i386 -d:release --app:lib --nomain mydll.nim
Hi there, I was able to return a Long value, now I'm trying to get string values.
I googled to find some exemples and find out here:
https://my.oschina.net/yuekcc/blog/775990
I'm getting this error:
VB6:
Private Declare Function MyStr Lib "mydll.dll" (ByVal s As String) As String
Private Declare Function return_multiply Lib "mydll.dll" Alias "return_multiply#8" (ByVal a As Long, ByVal b As Long) As Long
Private Sub Form_Click()
MsgBox MyStr("?") 'error
MsgBox return_multiply(5, 4) 'ok
End Sub
Another question, why the Alias has #8 at the end? return_multiply#8
Nim:
import encodings
const
vbCodePage = "GB2312"
vbTrue* = 1
vbFalse* = 0
type
VBString* = cstring
VBBoolean* = int32
proc MyStr*(): cstring {.stdcall, exportc, dynlib.} =
result = $"teste"
proc fromVBString*(a: VBString): string =
return encodings.convert($a, "UTF-8", vbCodePage)
proc toVBString*(a: string): VBString =
return VBString(encodings.convert(a, vbCodePage, "UTF-8"))
proc return_multiply*(a, b: int): int {.stdcall, exportc, dynlib.} =
a * b
Since you want to export toVBString in the dynamic library, you have to add the exportc, dynlib pragmas to it as to others:
proc toVBString*(a: string): VBString {.exportc, dynlib, stdcall.} =
return VBString(encodings.convert(a, vbCodePage, "UTF-8"))
But the definition is wrong anyway - I don't know what type VB's String is, but it certainly is different from the Nim string, and I'm not sure why you are importing it in your VB program.
Also, I don't think it's correct to just convert the Nim string to cstring to pass it to VB - Nim's cstring doesn't actually "own" the string data, so when the Nim runtime frees the Nim string, the cstring of it will point to invalid data. I don't know if VB has specific APIs for that or not though.
I know nothing about Nim, but the way to create a VB string is to make an OLE BSTR. SysAllocStringLen() would probably be your best bet. Others in that family might be better depending on what your string data looks like and where it comes from. Check out the MS docs.

Calling CryptCATCatalogInfoFromContext Throw errors

I want to call the function CryptCATCatalogInfoFromContext available in wintrust.dll. But when I do that I receive an error saying Specified array was not of the expected type.
I am using the following code to invoke method. It seems some data type I'm using is mismatching with the required data type.
'import wintrust.dll
<DllImport("Wintrust.dll", PreserveSig:=True, SetLastError:=False)> _
Private Shared Function CryptCATCatalogInfoFromContext(ByVal catalogContext As IntPtr, ByVal hash As CATALOG_INFO_, ByVal dwFlags As Integer) As Boolean
End Function
'create structure CATALOG_INFO
<StructLayout(LayoutKind.Sequential)> _
Public Structure CATALOG_INFO_
Public cbStruct As UInteger
<MarshalAs(UnmanagedType.SafeArray)> _
Public wszCatalogFile() As Char
End Structure
I have already obtained CatalogContext.
Dim infoStruct As New CATALOG_INFO_()
infoStruct.cbStruct = 256
Dim c(255) As Char
infoStruct.wszCatalogFile = c
CryptCATCatalogInfoFromContext(CatalogContext, infoStruct, 0)
the last line throws the error Specified array was not of the expected type.
Have I used a wrong data type for the array?
Yes, wrong declaration. It is not a SafeArray, it is a Unicode string. The proper declaration is:
<StructLayout(LayoutKind.Sequential, CharSet:=CharSet.Unicode)> _
Public Structure CATALOG_INFO
Public cbStruct As UInteger
<MarshalAs(UnmanagedType.ByValTStr, SizeConst:=260)> _
Public wszCatalogFile As String
End Structure

VB6: How to pass temporary to a function in Visual Basic 6

In C++ it is possible to pass a temporary object argument to a function:
struct Foo
{
Foo(int arg);
// ...
}
void PrintFoo(const Foo& f);
PrintFoo(Foo(10))
I am trying to implement something similar in Visual Basic 6:
'# Scroll bar params
Public Type ScrollParams
sbPos As Long
sbMin As Long
sbMax As Long
End Type
Public Function MakeScrollParams(pos As Long, min As Long, max As Long)
Dim params As ScrollParams
With params
.sbPos = pos
.sbMin = min
.sbMax = max
End With
Set MakeScrollParams = params
End Function
'# Set Scroll bar parameters
Public Sub SetScrollParams(sbType As Long, sbParams As ScrollParams)
Dim hWnd As Long
' ...
End Sub
However, Call SetScrollParams(sbHorizontal, MakeScrollParams(3, 0, 10)) raises an error: ByRef argument type mismatch. Why?
A couple of things need to change from your existing code:
You need to strongly-type the declaration of the MakeScrollParams function.
It returns an instance of the ScrollParams type, so you should specify that explicitly in the declaration. Like so:
Public Function MakeScrollParams(pos As Long, min As Long, max As Long) As ScrollParams
You need to remove the Set keyword from the last line in that function in order to avoid an "Object Required" compilation error. You can only use Set with objects, such as instances of classes. For regular value types, you omit it altogether:
MakeScrollParams = params
So the full function declaration would look like this:
Public Function MakeScrollParams(pos As Long, min As Long, max As Long) As ScrollParams
Dim params As ScrollParams
With params
.sbPos = pos
.sbMin = min
.sbMax = max
End With
MakeScrollParams = params
End Function
And calling it like this:
Call SetScrollParams(sbHorizontal, MakeScrollParams(3, 0, 10))
now works perfectly.
Maybe?
Public Function MakeScrollParams(pos As Long, min As Long, max As Long) As ScrollParams

String to Function Name in Visual Studio

I saw in a screencast a while ago (since forgotten which, probably a Kata) where a person was writing out a unit test but wrote something like this:
public "return zero for an all gutter game"
Then they magically turned it into
public returnZeroForAnAllGutterGame
Is there a plugin for this or just a simple way to do a template that gets fired off on a key stroke?
I googled around and just couldn't think of a good way to type in a search to get what I wanted.
I couldn't find the plugin or macro you refer to, but I did create a macro that will work nicely!
First, to install do the following:
Press Alt+F11
Expand MyMacros
Open the EnvironmentEvents module
Past the code into the module (code is found at the end of this post)
Close the macro editor
To use the macro:
Press ` (grave key).
Next press "
Type the words you desire
End by typing "`
Watch the magic happen!
NOTE: You could just start typing a sting value then latter add the grave symbols before and after and it will still work.
The macro will remove spaces and then PascalCase the entire set of words. It also strips out single and double quotes. Lastly, it will convert commas to underscores if you want to use the naming convention suggested by Roy Osherove (The Art of Unit Testing, p. 211):
MethodUnderTest_Scenario_Behavior()
Examples:
public void `"return zero for an all gutter game"`
public void `"LoadMainParts, when materials files are valid, will return a list of parts sorted by sequential item number ascending"`
...will turn into this (after the second ` press):
public void ReturnZeroForAnAllGutterGame
public void LoadMainParts_WhenMaterialsFilesAreValid_WillReturnAListOfPartsSortedBySequentialItemNumberAscending
The Macro:
...
Imports System.Text.RegularExpressions
...
Private isPascalCaseAndSpaceRemovalEnabled As Boolean
Private Function ConvertToPascalCase(ByVal value As String) As String
'apply ToUpper on letters preceeded by a space, double quotes, or a comma'
Dim pattern As String = "[ ,"",\,][a-z]"
value = Regex.Replace(value, _
pattern, _
Function(m) m.Value.ToUpper, _
RegexOptions.Singleline)
'replace commas with underscores'
value = value.Replace(",", "_")
'remove spaces, graves, double quotes, and single qoutes'
Dim removalCharacters As String() = {" ", "`", """", "'"}
For Each character In removalCharacters
value = value.Replace(character, "")
Next
Return value
End Function
Private Sub TextDocumentKeyPressEvents_AfterKeyPress(ByVal Keypress As String, _
ByVal Selection As EnvDTE.TextSelection, _
ByVal InStatementCompletion As Boolean) _
Handles TextDocumentKeyPressEvents.AfterKeyPress
If isPascalCaseAndSpaceRemovalEnabled AndAlso Keypress = "`" Then
Selection.SelectLine()
Dim pattern As String = "`""(.*)""`"
Dim substringToReplace As String = Regex.Match(Selection.Text, _
pattern, _
RegexOptions.Singleline).Value
Selection.ReplacePattern(pattern, _
ConvertToPascalCase(substringToReplace), _
vsFindOptions.vsFindOptionsRegularExpression)
Selection.MoveToPoint(Selection.BottomPoint)
isPascalCaseAndSpaceRemovalEnabled = False
CancelKeyPress = True
ElseIf Keypress = "`" Then
isPascalCaseAndSpaceRemovalEnabled = True
End If
End Sub
Feel free to tailor the code to your needs.

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