Conversion between array<String^>^ and const char *const* and back?

[Ed K]

Attempting to dig into C++/CLI by wrapping VLC with it. You'd know the very fist thing I run across is conversions between arrays in C++/CLI and C++. Are there any 'conversion' libraries/utilities out there?? Thanks,

ed ~"Watch your thoughts; they become your words. Watch your words they become your actions. Watch your actions; they become your habits. Watch your habits; they become your character. Watch your character; it becomes your destiny." -Frank Outlaw.

[N a v a n e e t h]

Ed K wrote:

Conversion between array<String^>^ and const char *const* and back

You don't need any library functions to do this. It's simple enough to write. Converting String^ to char*

String^ str = "Hello world!";
IntPtr p = Marshal::StringToHGlobalAnsi(str);
char *nativeString = static_cast<char*>(p.ToPointer());
Marshal::FreeHGlobal(p);

Converting char* to String^

const char* native = "hello world";
String^ managed = gcnew String(f);

Now you know the basic conversions and it will be easy to create const char *const* from a managed string array. :)

Best wishes, Navaneeth

[ian__lindsay 0]

If you are using .Net 3.5 or newer, you can use the marshalling library: http://msdn.microsoft.com/en-us/library/bb384865.aspx[^] For your example, the marshal_context methods are probably most appropriate, then you can leave RAII to clear up the HGlobal stuff internally. You will still need to loop over the array elements though.

[N a v a n e e t h]

ian__lindsay wrote:

For your example, the marshal_context methods are probably most appropriate, then you can leave RAII to clear up the HGlobal stuff internally.

Correct. Beauty of stack semantics! :)

Best wishes, Navaneeth

[Luc Pattyn]

N a v a n e e t h wrote:

It's simple enough to write.

Really? why does C++ need another type of string for each new string? after all, a string is a string. :laugh:

Luc Pattyn [Forum Guidelines] [Why QA sucks] [My Articles] Nil Volentibus Arduum

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[N a v a n e e t h]

Luc Pattyn wrote:

why does C++ need another type of string for each new string? after all, a string is a string.

Not sure I got you :confused:

Best wishes, Navaneeth

[Luc Pattyn]

It seems C++ offers more string types than I have strings in a typical app. Just wondering why that is. :)

Luc Pattyn [Forum Guidelines] [Why QA sucks] [My Articles] Nil Volentibus Arduum

Please use <PRE> tags for code snippets, they preserve indentation, and improve readability.

[N a v a n e e t h]

Luc Pattyn wrote:

It seems C++ offers more string types than I have strings in a typical app. Just wondering why that is.

Ok. I guess you are talking about the various string types shown in the marshal_context MSDN page. std::string is the only string type that C++ standard provides. Rest everything is non-standard. When it comes to C++/CLI, System::String^ is the standard string type. CString is Microsoft's implementation for MFC. :)

Best wishes, Navaneeth