CODEWITHSUNDEEP
c++arraysmanagedmanaged-c++
Jonathan Prior
Jonathan Prior

Reputation: 6284

Arrays of strings in Managed C++

I'm trying to write an application in Managed C++, but I cannot work out how to declare an array of strings.

String^ linet[];

throws an error

'System::String ^' : a native array cannot contain this managed type

So I suppose there's a different way to do this for managed data types. What exactly is it?

Upvotes: 8

Views: 22593

Answers (3)

1800 INFORMATION
1800 INFORMATION

Reputation: 135295

You use a collection class from .Net. For example:

List<String^>^ dinosaurs = gcnew List<String^>();

Upvotes: 1

cwap
cwap

Reputation: 11287

http://www.codeproject.com/KB/mcpp/cppcliarrays.aspx

That should have all the answers you need :)

When working with Managed C++ (aka. C++/CLI aka. C++/CLR) you need to consider your variable types in everything you do. Any "managed" type (basically, everything that derives from System::Object) can only be used in a managed context. A standard C++ array basically creates a fixed-size memory-block on the heap, with sizeof(type) x NumberOfItems bytes, and then iterates through this. A managed type can not be guarenteed to stay the same place on the heap as it originally was, which is why you can't do that :)

Upvotes: 4

Niki
Niki

Reputation: 15867

Do you really mean Managed C++? Not C++/CLI?

Assuming you're actually using C++/CLI (because of the error message you posted), there are two ways to do this:

array<String^>^ managedArray = gcnew array<String^>(10);

will create a managed array, i.e. the same type as string[] in C#.

gcroot<String^>[] unmanagedArray;

will create an unmanaged C++ array (I've never actually tried this with arrays - it works well with stl containers, so it should work here, too).

Upvotes: 11

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