How do you convert a string to a System::Object?

Question

I have my string:

myFunc(std::string text) {}

and I want to convert it into a System::Object. Something like...

array<Object^>^ inArgs = gcnew array<Object^>(2);
const char* ms;         
ms = text.c_str();
inArgs[1] = *ms;

Except when I try to get the string out it only gives me the first character.

...it doesn't have to be an std::string. a string of any type will do. im doing a cross thread update and trying to pass a string.

I think you mean, "How do you convert std::string to String^?", maybe. Anyway, search for Marshal::PtrToStringAnsi. — user2246674
– user2246674, Commented Aug 30, 2013 at 20:42
omg that worked! thanks! if you post that as an answer i will accept it. — user1873073
– user1873073, Commented Aug 30, 2013 at 20:44
Post the code you ended up using with relevant resources/links and self-accept :-) — user2246674
– user2246674, Commented Aug 30, 2013 at 20:45

Hans Passant · Accepted Answer · 2013-08-30 21:06:34Z

3

System::String has a constructor that accepts a const char*. You don't sound picky about the proper code page conversion so it will probably be fine:

  std::string test("hello world");
  auto managed = gcnew String(test.c_str());
  Console::WriteLine(managed);

answered Aug 30, 2013 at 21:06

Hans Passant

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Comments

user1873073 · Accepted Answer · 2013-08-30 20:52:24Z

This code is probably far from the right way. I just emulated what I do in C# for cross thread updates. The actual answer came from the comments.

init form, setup delegates, start the second thread:

public ref class Form_1 : public System::Windows::Forms::Form
{
    public:
        CL* c;
        delegate System::Void CrossThreadUpdate(Object^ obj);
        CrossThreadUpdate^ crossThreadUpdate;
        void update(Object^ obj);
        Thread^ t;
        void updateTextArea(String^ text);
        void initCL();

        Form_1(void)
        {
            InitializeComponent();
            crossThreadUpdate = gcnew CrossThreadUpdate(this, &Form_1::update);
            t = gcnew Thread(gcnew ThreadStart(this, &Form_1::initCL));
            t->Start();
            //
            //TODO: Add the constructor code here
            //
        }

thread does its thing and then lets us know its done

void Form_1::initCL() 
{
    c = new CL();
    updateTextArea("CL READY");
}

update the form

void Form_1::update(Object^ obj) {
        array<Object^>^ arr = (array<Object^>^)obj;
        int^ op = safe_cast<int^>(arr[0]);

        switch(*op)
        {
            case 1:
                String^ text = safe_cast<String^>(arr[1]);
                wstring stringConvert = L"";
                MarshalString(text, stringConvert);
                wcout << stringConvert << endl;
                this->textBox1->Text += text + "\r\n";
                break;
        }
    }

    void Form_1::updateTextArea(String^ text) {
        array<Object^>^ args = gcnew array<Object^>(1);
        array<Object^>^ inArgs = gcnew array<Object^>(2);
        inArgs[0] = 1;
        inArgs[1] = text;
        args[0] = inArgs;
        this->Invoke(crossThreadUpdate, args);
    }

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