CODEWITHSUNDEEP
c++-clistreamwriterstd
charan-tennakoon
charan-tennakoon

Reputation: 81

Give a std::string to StreamWriter to write a txt file

I want give a string as a argument to the Stream Writer writeline method in visual c++

StreamWriter^ sw = gcnew StreamWriter("Positive Sample.txt");

string Loc = "blabla";

sw->WriteLine(Loc);

It generating a error - no instance of overload function match the argument list

Upvotes: 2

Views: 2922

Answers (1)

Nemanja Boric
Nemanja Boric

Reputation: 22157

WriteLine method accepts CLI's String, and not std's string.

StreamWriter^ sw = gcnew StreamWriter("Positive Sample.txt");

String^ Loc = "blabla";

sw->WriteLine(Loc);

You can use System::Runtime::InteropServices::Marshal::PtrToStringAnsito marshal from C string to String, or you can pass C string into String's constructor:

string Loc = "blabla";
String^ strLoc = gcnew String(Loc.c_str());

EDIT

As Ben pointed out in the comments, you should use marshal_as instead PtrToStringAnsi:

Example from here (inverse operation could be found here)

// marshal_as_test.cpp
// compile with: /clr
#include <stdlib.h>
#include <string.h>
#include <msclr\marshal.h>

using namespace System;
using namespace msclr::interop;

int main() {
   const char* message = "Test String to Marshal";
   String^ result;
   result = marshal_as<String^>( message );
   return 0;
}

Upvotes: 3

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