CODEWITHSUNDEEP
arraysc++-cli
Thealon
Thealon

Reputation: 1945

Char pointer to char array

So I have this method that returns a char pointer:

Private: char* currentSelectedDevice()
         {
            String^ comboboxText = counterComboBox->Text;
            marshal_context ^ context = gcnew marshal_context();
            char* temp;
            cont char* convertedString = context->marshal_as<const char*>(comboboxText);
            temp = const_cast<char *>(convertedString);
            char* oneCounterPort = strtok (temp, " =");
            return oneCounterPort;
         }

What I'm trying to achieve is to copy this method to a char array. I was thinking of using a for loop but that didn't work out as I wanted. So how can I do this?

I was thinking something like this might work:

char temp[sizeof(currentSelectedDevice())] = currentSelectedDevice();

Upvotes: 2

Views: 984

Answers (1)

Stefan Falk
Stefan Falk

Reputation: 25397

You can use Marshal::Copy. Your functoin would look like this:

#include <stdlib.h> // In case you use C (for malloc() access)

// C++/CLI function
char * currentSelectedDevice()
{
    String^ comboBoxText = counterComboBox->Text;

    // Allocate unmanaged memory:
    char *result = (char*)malloc(comboBoxText->Length);

    // Copy comboBoxText to result:
    Marshal::Copy( comboBoxText ->ToCharArray(), 0, IntPtr( (char*) result ), comboBoxText->Length );

    return result;
}

It copies the content of comboBoxText (note the call of ToCharArray() here) from location 0 to comboBoxText.Length into result.

The calling C function will then e.g. can use it like this:

// Calling C function
void read_combo_box_text()
{
  // Get text:
  char * cbxText = currentSelectedDevice();

  // .. Do something with it

  // Free (if don't needed anymore)
  free(cbxText);
}

Hope this helps.

Note: If you do this for C++ don't include stdlib.h and replace malloc() by new and free() by delete[].

Upvotes: 1

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