I am relatively new to programming in VB, so please be patient with my frustration.
I am trying to declare a class using VB in Visual Studio 2010 Ultimate, and I'm following along with a tutorial, but Intellisense keeps messing with my code. Here's something along the lines of what I'm trying to write:
Import HYSYS
Dim myVar As Variant
...
Public Class MyClassVB1
Dim hyContainer As Object
Public Function Initialize(ByVal Container As Object, ByVal IsRecalling As Boolean) As Long
Set hyContainer = Container
End Function
However, Visual Studio turns my code into this:
Import HYSYS
Dim myVar As VariantType
...
Public Class MyClassVB1
Dim hyContainer As Object
Public Function Initialize(ByVal Container As Object, ByVal IsRecalling As Boolean) As Long
SetAttr() hyContainer = Container
End Function
After arguing with Visual Studio for a while, I finally have the message Let and Set assignment statements are no longer supported.
Is there a replacement that I'm supposed to use, or does Visual Studio just assume that I mean Variant if I don't explicitly specify a type?
Likewise, do I need to use a keyword or function for variable assignment, or can I treat it like I would in c++ and just write hyContainer = Container?
Set, as you're using it, is left over from the vb6/vbscript days.
It no longer works like that in VB.Net. You never ever use it for assignment.
You may be following an obsolete tutorial. In VB.Net, Set is only used as part of a LINQ query.
Variant is similar. It is no longer part of the VB language at all, and has not been for more than 10 years.
Related
Here is my function in .Net:
<Runtime.InteropServices.ComVisibleAttribute(True)>
Public Function Unhex(hex As String) As Double()
Dim GetArr As Double() = HexStringToDoubleArray(hex)
Return GetArr
End Function
Here is how I would like to use it in VBA:
Dim ret() As Double
ret = LinkToComLib.Unhex("EDC531...")
There are hundreds of examples of how to pass arrays into .Net (eg), but the only one I found showing the opposite is this MS page, and it doesn't show it being used on the VBA (or even COM) side. Perhaps I am using the wrong search terms. In any event:
Can I use the MarshalAs to export the Double() from .Net, or will I need to use Marshal.Copy or similar (as I suspect, as it is managed)?
If I do have to Copy, is the proper return type then IntPtr?
Am I correct in thinking that Dim ret() As Double is a pointer to a malloc'ed array or perhaps SAFEARRAY? Is that the proper type to use in VBA in this case?
Would creating the array with the proper size (it's always 492!) in VBA and then passing that to the function help in any way? Deallocing perhaps?
If anyone has a pointer to an example of this - a double (or int) array being passed out of .Net along with the corresponding VBA code, I can likely take it from there. But if someone has answers for the above, VB.Net or C# as they like, I'd appreciate it.
You need to decorate the return with <MarshalAs(UnmanagedType.SafeArray)> attribute.
VB.Net Example:
Imports System.Runtime.InteropServices
<ComClass(ArrayExample.ClassId, ArrayExample.InterfaceId)> _
Public Class ArrayExample
' These GUIDs provide the COM identity for this class and its COM interfaces.
Public Const ClassId As String = "e510d899-dad1-412b-94ea-6c726fe9f9da"
Public Const InterfaceId As String = "ef3498f0-22b4-4c2a-aeb1-22936c9757eb"
Public Function Unhex(hex As String) As <MarshalAs(UnmanagedType.SafeArray)> Double()
Dim GetArr As Double() = {2.0R, 5.0R}
Return GetArr
End Function
End Class
VBA Usage:
Sub t()
Dim c As ExampleComArrayReturn.ArrayExample
Set c = New ExampleComArrayReturn.ArrayExample
Dim arr() As Double
arr = c.Unhex("AABB")
End Sub
Edit: Forgot to mention that this uses the ComClassAttribute Class to have the compiler generate the interfaces for your class.
Edit 2 in response to follow-up question.
To debug your COM library project, go to the Debug tab of project properties. Select "Start External Program" and set it to run Excel. You can also specify the Workbook to open in the "Command line Arguments". Now when you click on the "Start" button, Excel will be launched and break points in your code will be triggered.
Edit 3:
To address the issue of targeting .Net 3.5, you can use a slightly less convenient method of attaching the debugger to the Excel process. If you are using VS2008, the method described above will work. New VS versions will need to attach to the process. There may be a way to specify this info in the vproj.user file, but I have not found the magic property type to allow direct launching using a specific framework version.
Depending on your VS version the "Attach To Process" item will either be under the Tools (VS2013) or the Debug (VS2017) menu or you can use the shortcut cntrl-alt-p.
Obviously start Excel and load your Workbook. Then in VS launch the Attach to Process dialog. Click the "Select" button and then click on the "Debug these type" radiobutton. Select the "Managed (v3.5, v3.0, v2.0) code" type and click the "OK" button. Then select the Excel process and click "Attach".
Compile Error:
Compile Error: Only user-defined types defined in public object
modules can be coerced to or from a variant or passed to a late-bound
functions.
I'm new to VBA and I was tasked with debugging some code for a custom screen in Dynamics SL. The first thing I did was to see if it compiled and I got the above message.
When I read the built-in help reference I found the following for the above error:
You attempted to use a public user defined type as a parameter or
return type for a public procedure of a class module, or as a field of
a public user defined type. Only public user defined types that are
defined in a public object module can be used in this manner.
I also went through these similar questions:
How to put user defined datatype into a Dictionary
Only user-defined type defined in public object modules can be coerced when trying to call an external VBA function
They have the same error but I don't see a collection object that the above two questions focused on.
If you may have any idea what may be causing this error please don't hesitate to suggest it.
Code:
Private Sub cpjt_entity_Chk(ChkStrg As String, retval As Integer)
Dim ldDate As Sdate
Dim xStrDailyPost As Sdate
ldDate.val = GetObjectValue("cpe_date")
'xStrDailyPost = DateToStr(ldDate)
'Call MsgBox("Daily Post Date: " & xStrDailyPost, vbOKOnly, "TEST")
serr1 = SetObjectValue("cld_id08", xStrDailyPost) <- Error highlights "xStrDailyPost"
End Sub
Definition for SetObjectValue:
Declare Function SetObjectValue Lib "swimapi.dll" Alias "VBA_SetObjectValue" (ByVal ctlname$, newval As Variant) As Integer
Thank you in advance!
You are probably working with code that was originally written with the Dynamics SL (actually it was Solomon IV at the time) Basic Script Language (BSL) macro language instead of VBA.
Regardless... the fix is, pass results of the "val" method of your xStrDailyPost instance of SDate. SO the code should look like:
serr1 = SetObjectValue("cld_id08", xStrDailyPost.val)
I've not actually tested this but I'm pretty sure this will address your issue.
If you want a little more background, "Sdate" is really just a very thin wrapper of an integer (actually I think it's a short, but I've never found I really needed to know for sure). the "Val" method returns the underlying integer in the SDate variable.
I'm building a program in VB whose purpose is to run in the background and automatically update other programs I've created. To do this, it has to check if those programs are still running and, if they are, wait for them to close.
Unfortunately, the program won't compile. The exception states: GetProcessesByName is not a member of String. (The string it refers to is the Process parameter shown in the code below.)
I can't understand why this is happening, because this method has always worked without problems. I'm using Visual Studio 2015. For your reference, here's the code block:
Private Function CheckIfRunning(Process As String) As Boolean
Dim MyProcess() As Process
MyProcess = Process.GetProcessesByName("ProcessName")
If MyProcess.Count > 0 Then
Return True
Else
Return False
End If
End Function
Try using System.Diagnostics.Process.GetProcessesByName("ProcessName")
Since you've declared Process as a string parameter, Process.GetProcessesByName refers to the string instead of the System.Diagnostics method. Alternatively, you can use a different name for the string parameter.
Does VB.NET have a direct equivalent to C# out function parameters, where the variable passed into a function does not need to be initialised?
No, there is no equivalent of the out keyword in VB.
However, VB does automatically initialise all local variables in a method, so you can use ByRef without needing to explicitly initialise the variable first.
Example:
Sub Main()
Dim y As Integer
Test(y)
End Sub
Sub Test(ByRef x As Integer)
x = 42
End Sub
(If you examine code in the framework (for example Double.TryParse), you may see the <OutAttribute> added to parameters, but that only makes a difference when the call is marshalled for COM interop or platform invoke.)
No, there is no equivalent construct that allows a non-initialised variable to be passed to a method without a warning, but, as mentioned in my question and answer specifying an <Out()> attribute on a ByRef parameter definition, although VB ignores it, is treated by C# as an out parameter.
So, I would pre-initialise reference variables to Nothing and specify <Out()> ByRef to signify the intention (that will work if C# users ever access your methods).
If you feel you know when you intend to access the default Nothing in otherwise unassigned reference variables you can set the "Warning configuration" "Use of variable prior to assignment" to "None" at the Project level (Project Properties > Compile, and you probably want to set Configuration to "All Configurations" before changing this setting), or, in VS2015 (VB.NET 14), you can use #Disable Warning BC42030.
C# version
void TestFunc(int x, ref int y, out int z) {
x++;
y++;
z = 5;
}
Vb.net version
Sub TestFunc(ByVal x As Integer, ByRef y As Integer, ByRef z As Integer)
x += 1
y += 1
z = 5
End Sub
Found the answer here
Update
As stated in the comment do not forget to initialze your parameter that will be used in the out slot
I had the problem in VB.NET that I called a function "by ref" that passed an array back.
Even though the compiler flagged it as a warning it was fine. The fix is super simple and probably good programming practice.
I changed
Dim m_arr_values() as Integer
fnRetArray(m_arr_values)
to
' Even though 'Nothing' is the default value, setting it
' stops the compiler complaining.
Dim m_arr_values() as Integer = Nothing
fnRetArray(m_arr_values)
It also helps when coding if variable names are descriptive...
Sub fnCreatePalette(ByRef arr_in_pal() As color, ByRef arr_out_pal() as uinteger)
...
End Sub
VB has the attribute which should be the same as C# out but today you still get a warning even if you use it. There are details about fixing it in vblang area of github. https://github.com/dotnet/vblang/issues/67.
You can use the pass by reference method in VB.NET.
You need the Out parameter mechanism in C#, because it doesn't let you use any variable without initializing it.
VB.NET doesn't need a special keyword as it automatically does it by itself.
Just use ByRef.
Use keyword ByRef before variable.
I am trying to create a custom vb.net Excel 2007 function (UDF) using VS 2010 and have gotten to this stage (borrowing heavily from Eric Carter's example at http://blogs.msdn.com/b/eric_carter/archive/2004/12/01/273127.aspx):
Namespace AutomationAddin
<Guid("1aeeb1b5-e099-4f7f-aeb0-3e9f19b64f62")>
<ClassInterface(ClassInterfaceType.AutoDual)>
<ComVisible(True)>
Public Class MyFunctions
Public MyFunctions()
Public Function MultiplyNTimes(ByVal number1 As Double, ByVal number2 As Double, ByVal timesToMultiply As Double) As Double
Dim result As Double = number1
For i As Integer = 0 To timesToMultiply - 1
result = result * number2
Next
Return result
End Function
<ComRegisterFunctionAttribute()>
Public Shared Sub RegisterFunction(ByVal type As Type)
Registry.ClassesRoot.CreateSubKey(GetSubKeyName(type, "Programmable"))
Dim key As RegistryKey = Registry.ClassesRoot.OpenSubKey(GetSubKeyName(type, "InprocServer32"), True)
key.SetValue("", (System.Environment.SystemDirectory + "\mscoree.dll"), RegistryValueKind.String)
End Sub
<ComUnregisterFunctionAttribute()>
Public Shared Sub UnregisterFunction(ByVal type As Type)
Registry.ClassesRoot.DeleteSubKey(GetSubKeyName(type, "Programmable"), False)
End Sub
Private Shared Function GetSubKeyName(ByVal type As Type, ByVal subKeyName As String) As String
Dim s As System.Text.StringBuilder = New System.Text.StringBuilder
s.Append("CLSID\{")
s.Append(type.GUID.ToString.ToUpper)
s.Append("}\")
s.Append(subKeyName)
Return s.ToString
End Function
End Class
End Namespace
However, when I build it using VS 2010 and try to load it in Excel 2007 using the Addin Manager>Automation I find it listed as AutomationAddin.AutomationAddin.MyFunctions and click OK only to get the error "AutomationAddin.AutomationAddin.MyFunctions is not a valid add-in." I have set the Build settings to Register for COM interop.
I've had a look online and tried following this article How to get COM Server for Excel written in VB.NET installed and registered in Automation Servers list? but to no avail. I checked my registry (after I built my project) and under CLSID/{myGuid}/InprocServer32/Default the data is set to C:\WINDOWS\system32\mscoree.dll and CLSID/{myGuid}/Programmable already exists.
I am not quite sure what I am doing wrong and would appreciate any guidance or suggestions on the topic.
Cheers,
Ben
You might want to check out this article (Build and Deploy a .NET COM Assembly) which might be helpful in your case.
I don't know if this is relevant to the question (especially after all this time) but I originally started with a COM add-in (created using Visual Studio 2010's Excel 2010 add-in project builder). I then added an automation add-in (for UDFs) by hand in the same project using the Eric Carter blog and other examples. The two worked fine independently. It was only after combining the two in the same namespace (for some obsessively tidy reason) that I started getting the "... is not a valid add-in" error. Spent a day tearing my hair out and then separated the namespaces again - problem went away.