Converting std::string or string^ to byte array in c++/cli

Question

I know this is a frequently asked question and I havent got a clear answer for converting a std::string or String^ to a byte array for writing in to a stream for tcp communication.

This is what I have tried

bool CTcpCommunication::WriteBytes(const std::string& rdatastr)
{
  bool retVal = false;

  try
  {
    if (static_cast<NetworkStream^>(stream) != nullptr)
    {
      array<Byte>^data = System::Text::Encoding::ASCII->GetBytes(rdatastr); 
      stream->Write( data, 0, data->Length ); 
    }
  }
  catch(Exception^)
  {
    // Ignore, just return false
  }
  return retVal;
}

I know that here the GetBytes wont work and I have also checked marshalling options to convert std:string to .NET String but havent found out any.Can someone help me in solving this..

Marshaling to .NET String, which is well described *everywhere*, has nothing to do with this, you're trying to make a `array` — Ben Voigt, Jul 06 '12 at 04:29

Ben Voigt · Accepted Answer · 2012-07-06T12:12:15.293

5

The encoding is already correct, no conversion needed. Just copy:

array<Byte>^ data = gcnew array<Byte>(rdatastr.size());
System::Runtime::InteropServices::Marshal::Copy(IntPtr(&rdatastr[0]), data, 0, rdatastr.size());

edited Jul 06 '12 at 12:12

answered Jul 06 '12 at 04:28

Ben Voigt

277,958
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@ShivShambo: Full type name added. – Ben Voigt Jul 06 '12 at 04:36
..thanks.. the error now says C2440: '' : cannot convert from 'const char *' to 'System::IntPtr' – ShivShambo Jul 06 '12 at 06:18
@ShivShambo: Oh yeah, stupid BCL and lack of const-correctness. This edit should fix it. – Ben Voigt Jul 06 '12 at 12:11

score 3 · Answer 2 · answered Aug 23 '16 at 01:19

3

What about this method:

String ^sTemp;
array<Byte> ^TxData;

sTemp = "Hello";
TxData = System::Text::Encoding::UTF8->GetBytes(sTemp);

Link: http://www.electronic-designer.co.uk/visual-cpp-cli-dot-net/strings/convert-string-to-byte-array

answered Aug 23 '16 at 01:19

A.Clymer

472
3
9

score 0 · Answer 3 · answered Jul 06 '12 at 07:42

0

This worked for me..Thanks to Ben

IntPtr ptr((void*)rdatastr.data());
array<Byte>^ data = gcnew array<Byte>(rdatastr.size()); 
System::Runtime::InteropServices::Marshal::Copy(ptr, data, 0, rdatastr.size())

answered Jul 06 '12 at 07:42

ShivShambo

523
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Converting std::string or string^ to byte array in c++/cli

3 Answers3