English 中文(简体)
Marshaling Delphi 5 OleVariant to C#
原标题:

I m trying to use some legacy Delphi 5 DLLs from C# (2.0/3.5). Some of the exported functions are declared as such:

function SimpleExport: OleVariant; stdcall;
function BiDirectionalExport(X: OleVariant; var Y: OleVariant): OleVariant; stdcall;

I wish to set these up as delegates using Marshal.GetDelegateForFunctionPointer, but I m having trouble getting the data Marshaled correctly. I m using kernel32 imports of LoadLibrary and GetProcAddress, so I m relying on GetDelegateForFunctionPointer to do my actual marshaling, not static p/invoke declarations.

Since the .NET marshaling services can marshal objects to COM OleVariants, I tried this. But this causes an exception: "PInvoke restriction: can not return variants.". So I m figuring I need to use a custom marshaller.

What s the correct way to Marshal a Delphi 5 OleVariant into something .NET readable?

问题回答

Since OleVariant can be nearly any type, and all types in C# can be handled as objects I would try system.object.

Also this link may be helpful.





相关问题
Manually implementing high performance algorithms in .NET

As a learning experience I recently tried implementing Quicksort with 3 way partitioning in C#. Apart from needing to add an extra range check on the left/right variables before the recursive call, ...

Anyone feel like passing it forward?

I m the only developer in my company, and am getting along well as an autodidact, but I know I m missing out on the education one gets from working with and having code reviewed by more senior devs. ...

How do I compare two decimals to 10 decimal places?

I m using decimal type (.net), and I want to see if two numbers are equal. But I only want to be accurate to 10 decimal places. For example take these three numbers. I want them all to be equal. 0....

Exception practices when creating a SynchronizationContext?

I m creating an STA version of the SynchronizationContext for use in Windows Workflow 4.0. I m wondering what to do about exceptions when Post-ing callbacks. The SynchronizationContext can be used ...

Show running instance in single instance application

I am building an application with C#. I managed to turn this into a single instance application by checking if the same process is already running. Process[] pname = Process.GetProcessesByName("...

How to combine DataTrigger and EventTrigger?

NOTE I have asked the related question (with an accepted answer): How to combine DataTrigger and Trigger? I think I need to combine an EventTrigger and a DataTrigger to achieve what I m after: when ...

热门标签