How to: Convert Between Various String Types

Converting from char *

Example

This example demonstrates how to convert from a char * to the other string types listed above.

// convert_from_char.cpp
// compile with: /clr /link comsuppw.lib

#include 
#include 
#include 

#include "atlbase.h"
#include "atlstr.h"
#include "comutil.h"

using namespace std;
using namespace System;

int main()
{
   char *orig = "Hello, World!";
   cout << orig << " (char *)" << endl;

   // Convert to a wchar_t*
   size_t origsize = strlen(orig) + 1;
   const size_t newsize = 100;
   size_t convertedChars = 0;
   wchar_t wcstring[newsize];
   mbstowcs_s(&convertedChars, wcstring, origsize, orig, _TRUNCATE);
   wcscat_s(wcstring, L" (wchar_t *)");
   wcout << wcstring << endl;

   // Convert to a _bstr_t
   _bstr_t bstrt(orig);
   bstrt += " (_bstr_t)";
   cout << bstrt << endl;

   // Convert to a CComBSTR
   CComBSTR ccombstr(orig);
   if (ccombstr.Append(L" (CComBSTR)") == S_OK)
   {
       CW2A printstr(ccombstr);
       cout << printstr << endl;
   }

   // Convert to a CString
   CString cstring(orig);
   cstring += " (CString)";
   cout << cstring << endl;

   // Convert to a basic_string
   string basicstring(orig);
   basicstring += " (basic_string)";
   cout << basicstring << endl;

   // Convert to a System::String
   String ^systemstring = gcnew String(orig);
   systemstring += " (System::String)";
   Console::WriteLine("{0}", systemstring);
   delete systemstring;
}

Output

Hello, World! (char *)
Hello, World! (wchar_t *)
Hello, World! (_bstr_t)
Hello, World! (CComBSTR)
Hello, World! (CString)
Hello, World! (basic_string)
Hello, World! (System::String)

Converting from wchar_t *

Example

This example demonstrates how to convert from a wchar_t * to the other string types listed above.

// convert_from_wchar_t.cpp
// compile with: /clr /link comsuppw.lib

#include 
#include 
#include 

#include "atlbase.h"
#include "atlstr.h"
#include "comutil.h"

using namespace std;
using namespace System;

int main()
{
   wchar_t *orig = L"Hello, World!";
   wcout << orig << L" (wchar_t *)" << endl;

   // Convert to a char*
   size_t origsize = wcslen(orig) + 1;
   const size_t newsize = 100;
   size_t convertedChars = 0;
   char nstring[newsize];
   wcstombs_s(&convertedChars, nstring, origsize, orig, _TRUNCATE);
   strcat_s(nstring, " (char *)");
   cout << nstring << endl;

   // Convert to a _bstr_t
   _bstr_t bstrt(orig);
   bstrt += " (_bstr_t)";
   cout << bstrt << endl;

   // Convert to a CComBSTR
   CComBSTR ccombstr(orig);
   if (ccombstr.Append(L" (CComBSTR)") == S_OK)
   {
       CW2A printstr(ccombstr);
       cout << printstr << endl;
   }

   // Convert to a CString
   CString cstring(orig);
   cstring += " (CString)";
   cout << cstring << endl;

   // Convert to a basic_string
   wstring basicstring(orig);
   basicstring += L" (basic_string)";
   wcout << basicstring << endl;

   // Convert to a System::String
   String ^systemstring = gcnew String(orig);
   systemstring += " (System::String)";
   Console::WriteLine("{0}", systemstring);
   delete systemstring;
}

Output

Hello, World! (wchar_t *)
Hello, World! (char *)
Hello, World! (_bstr_t)
Hello, World! (CComBSTR)
Hello, World! (CString)
Hello, World! (basic_string)
Hello, World! (System::String)

Converting from _bstr_t

Example

This example demonstrates how to convert from a _bstr_t to the other string types listed above.

// convert_from_bstr_t.cpp
// compile with: /clr /link comsuppw.lib

#include 
#include 
#include 

#include "atlbase.h"
#include "atlstr.h"
#include "comutil.h"

using namespace std;
using namespace System;

int main()
{
   _bstr_t orig("Hello, World!");
   wcout << orig << " (_bstr_t)" << endl;

   // Convert to a char*
   const size_t newsize = 100;
   char nstring[newsize];
   strcpy_s(nstring, (char *)orig);
   strcat_s(nstring, " (char *)");
   cout << nstring << endl;

   // Convert to a wchar_t*
   wchar_t wcstring[newsize];
   wcscpy_s(wcstring, (wchar_t *)orig);
   wcscat_s(wcstring, L" (wchar_t *)");
   wcout << wcstring << endl;

   // Convert to a CComBSTR
   CComBSTR ccombstr((char *)orig);
   if (ccombstr.Append(L" (CComBSTR)") == S_OK)
   {
       CW2A printstr(ccombstr);
       cout << printstr << endl;
   }

   // Convert to a CString
   CString cstring((char *)orig);
   cstring += " (CString)";
   cout << cstring << endl;

   // Convert to a basic_string
   string basicstring((char *)orig);
   basicstring += " (basic_string)";
   cout << basicstring << endl;

   // Convert to a System::String
   String ^systemstring = gcnew String((char *)orig);
   systemstring += " (System::String)";
   Console::WriteLine("{0}", systemstring);
   delete systemstring;
}

Output

Hello, World! (_bstr_t)
Hello, World! (char *)
Hello, World! (wchar_t *)
Hello, World! (CComBSTR)
Hello, World! (CString)
Hello, World! (basic_string)
Hello, World! (System::String)

Converting from CComBSTR

Example

This example demonstrates how to convert from a CComBSTR to the other string types listed above.

// convert_from_ccombstr.cpp
// compile with: /clr /link comsuppw.lib

#include 
#include 
#include 

#include "atlbase.h"
#include "atlstr.h"
#include "comutil.h"
#include "vcclr.h"

using namespace std;
using namespace System;
using namespace System::Runtime::InteropServices;

int main()
{
   CComBSTR orig("Hello, World!");
   CW2A printstr(orig);
   cout << printstr << " (CComBSTR)" << endl;

   // Convert to a char*
   const size_t newsize = 100;
   char nstring[newsize];
   CW2A tmpstr1(orig);
   strcpy_s(nstring, tmpstr1);
   strcat_s(nstring, " (char *)");
   cout << nstring << endl;

   // Convert to a wchar_t*
   wchar_t wcstring[newsize];
   wcscpy_s(wcstring, orig);
   wcscat_s(wcstring, L" (wchar_t *)");
   wcout << wcstring << endl;

   // Convert to a _bstr_t
   _bstr_t bstrt(orig);
   bstrt += " (_bstr_t)";
   cout << bstrt << endl;

   // Convert to a CString
   CString cstring(orig);
   cstring += " (CString)";
   cout << cstring << endl;

   // Convert to a basic_string
   wstring basicstring(orig);
   basicstring += L" (basic_string)";
   wcout << basicstring << endl;

   // Convert to a System::String
   String ^systemstring = gcnew String(orig);
   systemstring += " (System::String)";
   Console::WriteLine("{0}", systemstring);
   delete systemstring;
}

Output

Hello, World! (CComBSTR)
Hello, World! (char *)
Hello, World! (wchar_t *)
Hello, World! (_bstr_t)
Hello, World! (CString)
Hello, World! (basic_string)
Hello, World! (System::String)

Converting from CString

Example

This example demonstrates how to convert from a CString to the other string types listed above.

// convert_from_cstring.cpp
// compile with: /clr /link comsuppw.lib

#include 
#include 
#include 

#include "atlbase.h"
#include "atlstr.h"
#include "comutil.h"

using namespace std;
using namespace System;

int main()
{
   CString orig("Hello, World!");
   wcout << orig << " (CString)" << endl;

   // Convert to a char*
   const size_t newsize = 100;
   char nstring[newsize];
   strcpy_s(nstring, orig);
   strcat_s(nstring, " (char *)");
   cout << nstring << endl;

   // Convert to a wchar_t*
   // You must first convert to a char * for this to work.
   size_t origsize = strlen(orig) + 1;
   size_t convertedChars = 0;
   wchar_t wcstring[newsize];
   mbstowcs_s(&convertedChars, wcstring, origsize, orig, _TRUNCATE);
   wcscat_s(wcstring, L" (wchar_t *)");
   wcout << wcstring << endl;

   // Convert to a _bstr_t
   _bstr_t bstrt(orig);
   bstrt += " (_bstr_t)";
   cout << bstrt << endl;

   // Convert to a CComBSTR
   CComBSTR ccombstr(orig);
   if (ccombstr.Append(L" (CComBSTR)") == S_OK)
   {
       CW2A printstr(ccombstr);
       cout << printstr << endl;
   }

   // Convert to a basic_string
   string basicstring(orig);
   basicstring += " (basic_string)";
   cout << basicstring << endl;

   // Convert to a System::String
   String ^systemstring = gcnew String(orig);
   systemstring += " (System::String)";
   Console::WriteLine("{0}", systemstring);
   delete systemstring;
}

Output

Hello, World! (CString)
Hello, World! (char *)
Hello, World! (wchar_t *)
Hello, World! (_bstr_t)
Hello, World! (CComBSTR)
Hello, World! (basic_string)
Hello, World! (System::String)

Converting from basic_string

Example

This example demonstrates how to convert from a basic_string to the other string types listed above.

// convert_from_basic_string.cpp
// compile with: /clr /link comsuppw.lib

#include 
#include 
#include 

#include "atlbase.h"
#include "atlstr.h"
#include "comutil.h"

using namespace std;
using namespace System;

int main()
{
   string orig("Hello, World!");
   cout << orig << " (basic_string)" << endl;

   // Convert to a char*
   const size_t newsize = 100;
   char nstring[newsize];
   strcpy_s(nstring, orig.c_str());
   strcat_s(nstring, " (char *)");
   cout << nstring << endl;

   // Convert to a wchar_t*
   // You must first convert to a char * for this to work.
   size_t origsize = strlen(orig.c_str()) + 1;
   size_t convertedChars = 0;
   wchar_t wcstring[newsize];
   mbstowcs_s(&convertedChars, wcstring, origsize, orig.c_str(), _TRUNCATE);
   wcscat_s(wcstring, L" (wchar_t *)");
   wcout << wcstring << endl;

   // Convert to a _bstr_t
   _bstr_t bstrt(orig.c_str());
   bstrt += " (_bstr_t)";
   cout << bstrt << endl;

   // Convert to a CComBSTR
   CComBSTR ccombstr(orig.c_str());
   if (ccombstr.Append(L" (CComBSTR)") == S_OK)
   {
       CW2A printstr(ccombstr);
       cout << printstr << endl;
   }

   // Convert to a CString
   CString cstring(orig.c_str());
   cstring += " (CString)";
   cout << cstring << endl;

   // Convert to a System::String
   String ^systemstring = gcnew String(orig.c_str());
   systemstring += " (System::String)";
   Console::WriteLine("{0}", systemstring);
   delete systemstring;
}

Output

Hello, World! (basic_string)
Hello, World! (char *)
Hello, World! (wchar_t *)
Hello, World! (_bstr_t)
Hello, World! (CComBSTR)
Hello, World! (CString)
Hello, World! (System::String)

Converting from System::String

Example

This example demonstrates how to convert from a System.String to the other string types listed above.

// convert_from_system_string.cpp
// compile with: /clr /link comsuppw.lib

#include 
#include 
#include 

#include "atlbase.h"
#include "atlstr.h"
#include "comutil.h"
#include "vcclr.h"

using namespace std;
using namespace System;
using namespace System::Runtime::InteropServices;

int main()
{
   String ^orig = gcnew String("Hello, World!");
   Console::WriteLine("{0} (System::String)", orig);

   pin_ptr wch = PtrToStringChars(orig);

   // Convert to a char*
   size_t origsize = wcslen(wch) + 1;
   const size_t newsize = 100;
   size_t convertedChars = 0;
   char nstring[newsize];
   wcstombs_s(&convertedChars, nstring, origsize, wch, _TRUNCATE);
   strcat_s(nstring, " (char *)");
   cout << nstring << endl;

   // Convert to a wchar_t*
   wchar_t wcstring[newsize];
   wcscpy_s(wcstring, wch);
   wcscat_s(wcstring, L" (wchar_t *)");
   wcout << wcstring << endl;

   // Convert to a _bstr_t
   _bstr_t bstrt(wch);
   bstrt += " (_bstr_t)";
   cout << bstrt << endl;

   // Convert to a CComBSTR
   CComBSTR ccombstr(wch);
   if (ccombstr.Append(L" (CComBSTR)") == S_OK)
   {
       CW2A printstr(ccombstr);
       cout << printstr << endl;
   }

   // Convert to a CString
   CString cstring(wch);
   cstring += " (CString)";
   cout << cstring << endl;

   // Convert to a basic_string
   wstring basicstring(wch);
   basicstring += L" (basic_string)";
   wcout << basicstring << endl;

   delete orig;
}

Output

Hello, World! (System::String)
Hello, World! (char *)
Hello, World! (wchar_t *)
Hello, World! (_bstr_t)
Hello, World! (CComBSTR)
Hello, World! (CString)
Hello, World! (basic_string)