(Original) C ++ string large character libraries: C-style string, STL string and. net string mutual neighbors (. net) (C/C ++) (C ++/CLI) (STL)

Abstract
Currently, Visual C ++ 9 has at least three types of strings: C-style string, STL string, and. net string. How can we interoperate these three strings?

Introduction
Use environment: Visual C ++ 9.0/Visual Studio 2008

When Momo receives a hardware card dealer's API for using C ++, he wants to go. net C # usage, of course, there is a good solution, because C ++/CLI is the only one that can understand. net and C ++. Finally, I suggest using C ++/CLI to import C ++ APIs, and then package them. NET component is used by C #. This raises a question: how can c-style string (char * s, char s []) be executed in C ++/CLI? success. net System: string?

Scenario 1:
C-style string, STL string character. Net string

This situation is more complicated than others. Generally, C ++ development dll must be packaged into. Net DLL for C.

Cstring2netstring. CPP/C ++/CLI

1 /*  
2 (C) oomusou 2007 Http://oomusou.cnblogs.com
3
4 Filename: cstring2netstring. cpp
5 Compiler: Visual C ++ 9.0/C ++/CLI 2.0
6 Description: Demo how to use string in C ++/CLI 2.0
7 Release: 07/23/2008 1.0
8 */
9
10 # Include " Stdafx. h "
11 # Include < String >
12
13 Using   Namespace System;
14 Using   Namespace STD;
15
16 Int Main (Array < String ^>   ^ ARGs ){
17 // C string & STL string to. Net string
18 Char C_s [] =   " Hello C " ;
19 String Stl_s =   " Hello STL " ;
20
21 String ^ Net_s1 = Gcnew string (c_s );
22 String ^ Net_s2 = Gcnew string (stl_s.c_str ());
23
24 Console: writeline (net_s1 );
25 Console: writeline (net_s2 );
26 }
27

Results

Hello C
Hello STL

You can use gcnew () to convert C-style string to STL string. net string, although it seems very simple, but at that time it took some time for research to discover.

Scenario 2:
. Netstring character C-style string, STL string

I haven't met this requirement yet. I just want to take a look at it.

Netstring2cstring. CPP/C ++/CLI

1 /*  
2 (C) oomusou 2007 Http://oomusou.cnblogs.com
3
4 Filename: netstring2cstring. cpp
5 Compiler: Visual C ++ 9.0/C ++/CLI 2.0
6 Description: Demo how to use string in C ++/CLI 2.0
7 Release: 07/23/2008 1.0
8 */
9
10 # Include " Stdafx. h "
11 # Include < String >
12 # Include " Stdio. h "
13 # Include < Iostream >
14 # Include < Msclr / Marshal. h > // . Net string to C-style string
15 # Include < Msclr / Marshal_cppstd.h >   // . Net string to STL string
16
17
18 Using   Namespace System;
19 Using   Namespace STD;
20 Using   Namespace Msclr: InterOP;
21
22 Int Main (Array < String ^>   ^ ARGs ){
23 // . Net string to C string
24 String ^ Net_s =   " Hello. net " ;
25 Marshal_context ^ Context = Gcnew marshal_context ();
26 Const   Char * C_s = Context -> Marshal_as < Const   Char *> (Net_s );
27 Printf ( " % S \ n " , C_s );
28
29 // . Net string to STL string
30 String Stl_s = Context -> Marshal_as < STD :: String > (Net_s );
31 Cout < Stl_s < Endl;
32 Delete context;
33 }

Results

Hello. net
Hello. net

This program requires the following three lines to be used, mainly by using al_as <t>. This is a unique usage of vc9 and cannot be used before vc8.

# Include < Msclr / Marshal. h > // . Net string to C-style string
# Include < Msclr / Marshal_cppstd.h >   // . Net string to STL string

Using   Namespace Msclr: InterOP;

25 rows

Marshal_context ^ Context = Gcnew marshal_context ();
Const   Char * C_s = Context -> Marshal_as < Const   Char *> (Net_s );

The. NET string can be converted to C-style string by using marshal_as <t>.

30 rows

// . Net string to STL string
String Stl_s = Context -> Marshal_as < STD :: String > (Net_s );

If you want to convert it to STL string and export al_as <t>, you only need to change it to STD: string.

All the string types that the financial_as <t> can interact with each other are sorted as follows.

Conclusion
C ++/CLI is a hypervisor.. NET and C/C ++. I really admire those coders who use C ++/CLI compiler, let the code of the two completely different worlds crash together. net, C, C ++, and STL merge methods can even run out of the results, it is very difficult to think.

Reference
How to convert from system: string * To char * in Visual C ++
STL/CLR: 2008 C ++/CLI tool of Zuse Cheng code blog