The description
I am writing a couple of Excel UDFs in COM Servers. I'd like to get the standard help (Insert Function dialog) that you get when you press fx. Yes, I can see my COM Server listed in among the Category drop down, but
I also see Equals, GetHashCode, GetType, and ToString (which are fairly undesirable to expose to the Excel user),
selecting my COM Server brings up the *Function Arguments*[1] dialog with no argument information and no description of the function.
Here is the lameness that I get:
Insert Function dialog http://www.iwebthereforeiam.com/files/Insert%20function%20dialog.gif
Excel Function Arguments dialog http://www.iwebthereforeiam.com/files/Function%20Arguments%20dialog.gif
The question
Are there .NET attributes I could put on the methods to pass this through to Excel?
Can I provide a description of the function?
Can I provide a description of the parameters?
Can I provide a category name for my functions, so that I get something better than just the ProgID?
(I see that it looks sadly easy to do in ExcelDNA, but I am not going that route. Emulating govert's code [custom attributes, a loader of some sort, etc.] looks like it would be pretty hard.)
Additional background
If you have not done work with Excel + COM Servers before, here are some useful resources to get up to speed:
Previous StackOverflow questions:
How to get COM Server for Excel written in VB.NET installed and registered in Automation Servers list?
How Add a COM-Exposed .NET Project to the VB6 (or VBA) References Dialog?
Other resources:
Writing user defined functions for Excel in .NET
Build and Deploy a .NET COM Assembly
Writing Custom Excel Worksheet Functions in C#
Edit 2009-10-20 14:10
I tried out calling Application.MacroOptions in a Sub New().
No Sub New()
Semi-acceptable: Function is listed under category ProgID.
Shared Sub New()
Not acceptable: build-time error.Cannot register assembly "...\Foo.dll".
Exception has been thrown by the target of an invocation.
Sub New()
Not acceptable: category is not listed in Insert Function dialog.
I suspect this is a problem both for MacroOptions and for the more involved route recommended by Charles.
Edit 2009-10-20 14:55
On the plus side, Mike's recommendation to create an interface to implement did kill off the annoying extra methods that were exposed.
Edit 2009-10-20 15:00
This Microsoft article from early 2007 (via Mike's link) seems a rather complete answer on the topic:
Automation Add-ins and the Function
Wizard
Each Automation Add-in has its own
category in the Excel Function Wizard.
The category name is the ProgID for
the Add-in; you cannot specify a
different category name for Automation
Add-in functions. Additionally, there
is no way to specify function
descriptions, argument descriptions,
or help for Automation Add-in
functions in the Function Wizard.
1 Huh, a StackOverFlow bug. It looks like you cannot italicize a string inside an explicit HTML ul-list?
Some of this is easy to correct, other parts of it is rather hard. All of it is do-able, though, if you are willing to put the time in.
You wrote:
I also see Equals, GetHashCode,
GetType, and ToString (which are
fairly undesirable to expose to the
Excel user)
Yes, agreed, this definitely undesirable, but it can be prevented. This is occurring because your class is inheriting from 'System.Object', as all .NET classes do, and your default interface that is exposed to COM is including these members. This occurs, for example, if you use the 'ClassInterfaceAttribute', using the setting 'ClassInterfaceType.AutoDual'.
E.g. in C#:
[ClassInterface(ClassInterfaceType.AutoDual)]
In VB.NET:
<ClassInterface(ClassInterfaceType.AutoDual)>
The use of 'ClassInterfaceType.AutoDual' should be avoided, however, in order to prevent the members inherited from 'System.Object' from being exposed (as well as to prevent potential versioning issues in the future). Instead, define your own interface, implement the interface in your class, and then mark your class with the 'ClassInterface' attribute with a value of 'ClassInterfaceType.None'.
E.g., using C#:
[ComVisible(true)]
[Guid("5B88B8D0-8AF1-4741-A645-3D362A31BD37")]
public interface IClassName
{
double AddTwo(double x, double y);
}
[ComVisible(true)]
[Guid("010B0245-55BB-4485-ABAF-46DF4356DB7B")]
[ProgId("ProjectName.ClassName")]
[ComDefaultInterface(typeof(IClassName))]
[ClassInterface(ClassInterfaceType.None)]
public class ClassName : IClassName
{
public double AddTwo(double x, double y)
{
return x + y;
}
}
Using VB.NET:
<ComVisible(True)> _
<Guid("5B88B8D0-8AF1-4741-A645-3D362A31BD37")> _
Public Interface IClassName
Function AddTwo(ByVal x As Double, ByVal y As Double) As Double
End Interface
<ComVisible(True)> _
<Guid("010B0245-55BB-4485-ABAF-46DF4356DB7B")> _
<ProgId("ProjectName.ClassName")> _
<ComDefaultInterface(GetType(IClassName))> _
<ClassInterface(ClassInterfaceType.None)> _
Public Class ClassName
Implements IClassName
Public Function AddTwo(ByVal x As Double, ByVal y As Double) As Double _
Implements IClassName.AddTwo
Return x + y
End Function
End Class
By making use of the 'ClassInterfaceAtribute' with a value of 'ClassInterfaceType.None', the inherited 'System.Object' memebers are excluded, because the class's interface is not made COM-visible. Instead, only the implemented interface ('IClassName' in this example) is exported to COM.
The above is also making use of the 'ComDefaultInterfaceAttribute'. This is not very important, and does nothing if you implement only one interface -- as in this example -- but it is a good idea in case you add an interface later, such as IDTExtensibility2.
For more detail on this, see:
(1) Managed Automation Add-ins by Andrew Whitechapel.
(2) Writing Custom Excel Worksheet Functions in C# by Gabhan Berry.
Ok, now to the hard part. You wrote:
Selecting my COM Server brings up the
Function Arguments[1] dialog with no argument information and no
description of the function.
Can I provide a description of the
function?
Can I provide a description of the
parameters?
Can I provide a category name for my
functions, so that I get something
better than just the ProgID?
The easiest approach here is to make use of the Application.MacroOptions method. This method enables you to provide a description of the function and specify which category under which you want it to be displayed. This approach does not allow you to specify any information for the functions parameters, unfortunately, but techniques that allow you to do so are very complicated, which I'll get to later. [Correction: The 'Application.MacroOptions' method only works for UDFs created via VBA and cannot be used for automation add-ins. Read on for more complex approaches to handle registration of UDFs containe in an automation add-ins -- Mike Rosenblum 2009.10.20]
Note that the help files for Excel 2003 and help files for Excel 2007 state that a string can be provided to the category argument in order to provide a custom category name of your choice. Beware, however, that the help files for Excel 2002 do not. I do not know if this is an omission in the Excel 2002 help files, or if this is a new capability as of Excel 2003. I'm guessing the latter, but you would have to test to be sure.
The only way to get your parameter information into the Function Wizard is to use a rather complex technique involving the 'Excel.Application.ExecuteExcel4Macro' method. Be warned though: many Excel MVPs have struggled with this approach and failed to produce a result that is reliable. More recently, though, it appears that Jan Karel Pieterse (JKP) has gotten it worked out and has published the details here: Registering a User Defined Function with Excel.
Skimming that article you'll see that it is not for the faint of heart. Part of the problem is that he wrote it for VBA / VB 6.0 and so all that code would have to be translated to VB.NET or C#. The key command, however, is the 'Excel.Application.ExecuteExcel4Macro' method, which is exposed to .NET, so everything should work fine.
As a practical matter, however, I vastly prefer using the 'Excel.Application.MacroOptions' approach because it is simple and reliable. It does not provide parameter information, but I have not yet had a strong need to motivate me to take on the 'ExecuteExcel4Macro' approach.
So, good luck with this, but my advice would be to utilize the 'MacroOptions', unless you are being paid by the hour. ;-)
-- Mike
Follow-up to Hugh's Replies
I tried out calling
Application.MacroOptions in a Sub
New().
No Sub New() Semi-acceptable: Function
is listed under category ProgID.
Shared Sub New() Not acceptable:
build-time error. Cannot register
assembly "...\Foo.dll". Exception has
been thrown by the target of an
invocation.
Sub New() Not acceptable: category is
not listed in Insert Function dialog.
I suspect this is a problem both for
MacroOptions and for the more involved
route recommended by Charles.
You can't use shared (aka "static") classes or constructors when exposing your classes to COM because COM has no knowledge of this concept and so it cannot compile -- as you found out! You might be able to apply a 'COMVisibleAttribute' with a value of 'False' to the shared constructor, to at least allow it to compile. But this wouldn't help you in this case anyway...
Trying to register your automation add-in via the automation add-in itself might prove tricky. I realize that this is desirable in order to keep it as a single, stand-alone component, but it might not be possible. Or at least this won't be easy.
The issue is that automation add-ins are demand loaded. That is, they are not really there until Excel attempts to access the first worksheet function from your automation add-in. There are two issues related to this:
(1) If you put your registration code within the constructor for your class, then, by definition, your function wizard information cannot exist until the function has been called for the first time.
(2) Your constructor might be executing when Excel is not ready to accept automation commands. For example, an automation add-in is typically demand-loaded when the user begins to type in the name of one of the user-defined functions (UDFs) defined in the automation add-in. The result is that the cell is in edit-mode when your automation add-in first loads. If you have automation code within your constructor during edit mode, many commands will fail. I do not know if the 'Excel.Application.MacroOptions' or 'Excel.Application.Excel4Macro' methods have a problem with this, but many commands will choke when trying to execute while the cell is in edit mode. And if the automation add-in is being loaded for the first time because it is being called while the Function Wizard is open, I have no idea if these methods can work right.
There is no easy solution to this if you wish to have your automation add-in to be completely stand-alone with no other support. You can, however, create a managed COM add-in that will register your automation add-in for you via 'Excel.Application.MacroOptions' or the 'Excel.Application.Excel4Macro' approach when Excel starts up. The managed COM add-in class can be in the same assembly as that of your automation add-in, so you still only need one assembly.
By the way, you could even use a VBA workbook or .XLA add-in to do the same -- use the Workbook.Open event in VBA to call the registration code. You just need something to call your registration code when Excel starts up. The advantage to using VBA in this case is that you could utilize the code from the Jan Karel Pieterse's Registering a User Defined Function with Excel article as-is, without having to translate it to .NET.
On the plus side, Mike's
recommendation to create an interface
to implement did kill off the annoying
extra methods that were exposed.
lol, I'm glad something worked!
This Microsoft article from early 2007
(via Mike's link) seems a rather
complete answer on the topic:
Automation Add-ins and the Function
Wizard
Each Automation Add-in has its own
category in the Excel Function Wizard.
The category name is the ProgID for
the Add-in; you cannot specify a
different category name for Automation
Add-in functions. Additionally, there
is no way to specify function
descriptions, argument descriptions,
or help for Automation Add-in
functions in the Function Wizard.
This is a limitation for the 'Excel.Application.MacroOptions' approach only. (My apologies, I had forgotten about this limitation of the 'Excel.Application.MacroOptions' method with respect to automation add-ins when I wrote my original answer, above.) The more-complex 'Excel.Application. ExecuteExcel4Macro ' approach, however, absolutely does work for automation add-ins. It should also work for .NET ("managed") automation add-ins as well, because Excel has no idea whether it is loading a COM automation add-in created via VB 6.0/C++ versus a managed COM automation add-in created using VB.NET/C#. The mechanics are exactly the same from the COM side of the fence because Excel has no idea what .NET is, or that .NET even exists.
That said, the 'Excel.Application.Excel4Macro' approach would definitely be a lot of work...
You could either use one of the .Net Excel systems such as ExcelDNA or ADDIN Express, or try to adapt one of the VBA/VB6 solutions: look at Laurent Longre's FunCustomise
http://xcell05.free.fr/english/index.html
or Jan Karel Pieterse's article at http://www.jkp-ads.com/Articles/RegisterUDF00.asp
which uses a function overloading hack.
Related
My goal is to list the procedures exposed by the compiled VBProject, as visible in the Excel Macros menu or when typing a cell formula which makes appear availble UDF. A Solution that list any member (Enum, Sub, Function, etc.) of a CodeModule or of the full VBProject would be ideal.
I am not looking for a code parsing solution.
I could find old mentions of a way to do so in VB with the VBIDE library, which ( should / used to ) expose a VBIDE.Member class (accessible via the CodeModule.Members property) with those interesting properties:
Member.Name As String
Member.Type As VBIDE.vbext_MemberType
Member.Scope As VBIDE.vbext_Scope
Here is a bigger list, probably exhaustive:
Bindable
DisplayBind
StandarMethod
Browsable
HelpContextID
StaticCategory
Hidden
Type
Code
Location
Name
UIDefault
Collection
PropertyPage
VBE
DefaultBind
RequestEdit
Description
Scope
For a reason I don't understand, I cannot access them via VBA and the VBIDE library, they are not even listed as hidden members in the Object Browser.
Is there a way to get them?
Rubberduck (previously known as Mat's Mug here on Stack Overflow) aka Mathieu Guindon suggests it is possible though: https://rubberduckvba.wordpress.com/2016/03/24/a-reflection-on-vba-reflection/
Another idea: how to use Reflection with VBA?
Again, he suggests it is possible: https://rubberduckvba.wordpress.com/2019/04/10/whats-wrong-with-vba/
Note: the Rubberduck COM Add-In that integrates with the VBE, is able to do it (using .NET as I understand it)
Many software products have VBA incorporated into them. This includes Microsoft Office of course, but there are many 3rd-party products which have chosen to include VBA as well. A quick Google search turned up names like AutoCad, WordPerfect, PowerTerm, and ScriptWorx.
If one wishes to use #If/#EndIf directives to design a Sub or Function to work in multiple environments, how can VBA detect which one it's currently running in..??
This is a bit different than detecting if a product is installed, in which case CreateObject() and an ErrorHandler could be used. Also, checking the References collection would not be definitive, since a VBA project might have multiple references to products other than the current one. For instance, an Access project might have a reference to Excel, and vice-versa (as many of mine do).
Say, I want to write a function that returns the name of the current file. Here's some pseudo-code using Access and Excel as examples.
Public Function CurrentFilename() As String
#If EnvironmentName="Access" Then
CurrentFilename = Access.Application.CurrentProject.Fullname
#ElseIf EnvironmentName="Excel" Then
CurrentFilename = Excel.Application.ActiveWorkbook.Fullname
#Else
MsgBox "Current VBA software environment is not recognized."
#End If
End Function
Is this possible..? If so, what's the magic constant or function to replace 'EnvironmentName'..?
I believe your best bet will be the Application.Name property. I can't confirm it works for all VBA implementations, but it appears to be consistent with MS products.
From the MSDN reference: https://msdn.microsoft.com/en-us/library/office/aa221371(v=office.11).aspx
(Questions with an answer of NO are still useful; they're just not the solution to the problem. Answers say, no, there is no built-in, you have to implement the dialog for yourself...)
In VBA, (ms-word, or ms-excel, but seems like a generic operation) is there any way to simply a provide a collection to a built in dialog in order to prompt the user to select a value from a list of values?
I can't believe there's not a built in method to do this, it seems like a such a generic operation that could be coded once and everybody would re-use it. I can certainly hand code it, but why bother if it's already in the vba libraries someplace.
I've searched for a solution, but it does appear that the standard answer is to hand code it.
My aproach would be to create a Form, add a ListBox, Ok, Cancel and the ShowModal property.
To use it first set the ListBox RowSource according to what you need:
https://msdn.microsoft.com/en-us/library/office/ff196460.aspx
Then make it visible, manage Ok/Cancel and then use the ItemsSelect property (multiselect is possible):
https://msdn.microsoft.com/en-us/library/office/ff823015.aspx
Yup, no such thing.
Hand-code it, and keep it as part of your VBA "toolbox" - make yourself an add-in that other VBA projects can reference, so you can reuse the code without having to rewrite it every time.
Then export the code modules from your host document, upload them to a GitHub repository, and share your solution with the world so the next person looking for it doesn't need to implement it from scratch again.
The VBA standard library is rather limited, and beyond MsgBox there isn't much available in terms of built-in UI. That's just how it is.
Question!
I have an add-in we created at work, say foo.xla, and it has a function foo_sub(arg1).
Now, I want to improve the way that foo_sub(arg1) behaves but withour editting the original add-in code, since as soon as they update it, I must migrate my code from the old add-in to the newer.
Is there a way I could write foo_sub(arg1) in a different add-in, say fee.xla, so that every time I call foo_sub from a worksheet the one that get's called is the one I wrote?
Thanks in advance
I had a lot of similar issues when trying to overload a constructor in VBA in Excel.
However, I think your problem is a little different. You're not necessarily trying to overload the function by providing a separate method with the same name and different parameters; you're trying to add a method with the exact same name, return type, and parameters and figure out a way to have Excel call your function rather than that of the add-in.
I'm not positive, but I don't think this is possible in Excel VBA. If you try to call a function that's defined in multiple places, it will get confused and tell you that it doesn't know which one to call.
You might create a wrapper function called my_foo_sub(arg1) which has custom code in it. Then, if you need to switch to the new foo_sub(arg1) when the .xla file is updated, you could just comment out your custom code and add a call to foo_sub(arg1). This is far from ideal, but it might help.
This may help: Function Overloading and UDF in Excel VBA
I inherited an very old application that I am in the process of updating it (I know, we should have rewrote it in VS 2008, but we purchased a company, which is how I was stuck with the relic). Using UpdateData(TRUE) to retrieve the changes made in the dialog controls, nothing is being updated. I have an edit control, with an integer variable, and an edit control with a string variable, assigned using the class wizard. Upon pressing the OK button, the UpdateData(TRUE) is executed to retrieve the new values from the disalog.
I seem to remember having a similar problem back when VS C++ 6.0 first came out, but have not used it since VS 2003 and C# became prevalent.
Thanks for any help in advance!
Bill
Check the DoDataExchange() method. It should have the logic for writing data to or reading it from the controls. If the programmers used the default implementastion, then there will be a DDX_... macro for each control that is being read/written. Just look at any other MFC dialogs (in your code or google) to see how the DDX commands should be written if they are missing.
Alternatively, if it's only 1 or 2 values you can easily just get the control and read it directly if you don't mind doing validation etc yourself. Get the ID of the control from the form designer and use something along the lines of:
CEditWnd *pWnd = GetDlgItem(ID_THECONTROL);
CString newValue = pWnd->GetWindowText();
...
You'll need to look at the content of the DoDataExchange method and see what it is doing. There is not sufficient information here to tell what could be going wrong other than that.