最近这几天做了一个兼职 ，主要是把C语言以及C#语言封装的dll，经过C++中转为Java语言支持的，主要其中的问题就是类型转换，在此列出常用类型的转换过程。

#include "stdafx.h"
#include
#include
#include
#include "www_cnblogs_com\cyjwdm0503.h"
#include
#include

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

//char* ->c#
System::String^ charptrtoCstring( const char* str )
{
? ? System::String^ str1? =? Marshal::PtrToStringAnsi((IntPtr)(char*)str);
? ? return str1;
}

//C#->char*
char* Cstringtocharptr( System::String^ s )
{
? ? char* buffer = (char*)(void*)Marshal::StringToHGlobalAnsi(s);
? ? return buffer;
}

//jstring ->char*
char* jstringTocharptr( JNIEnv *env, jstring jstr )
{ //UTF8/16转换成gb2312
? ? int length = (env)->GetStringLength(jstr );
? ? const jchar* jcstr = (env)->GetStringChars(jstr, 0 );
? ? char* rtn = (char*)malloc( length*2+1 );
? ? int size = 0;
? ? size = WideCharToMultiByte( CP_ACP, 0, (LPCWSTR)jcstr, length, rtn,(length*2+1), NULL, NULL );
? ? if( size <= 0 )
? ? ? ? return NULL;
? ? (env)->ReleaseStringChars(jstr, jcstr );
? ? rtn[size] = 0;
? ? return rtn;
}

//char* ->jstring
jstring charptrTojstring( JNIEnv* env, const char* str )
{//gb2312转换成utf8/16
? ? jstring rtn = 0;
? ? int slen = strlen(str);
? ? unsigned short * buffer = 0;
? ? if( slen == 0 )
? ? ? ? rtn = (env)->NewStringUTF(str );
? ? else
? ? {
? ? ? ? int length = MultiByteToWideChar( CP_ACP, 0, (LPCSTR)str, slen, NULL, 0 );
? ? ? ? buffer = (unsigned short *)malloc( length*2 + 1 );
? ? ? ? if( MultiByteToWideChar( CP_ACP, 0, (LPCSTR)str, slen, (LPWSTR)buffer, length ) >0 )
? ? ? ? ? ? rtn = (env)->NewString(? (jchar*)buffer, length );
? ? }
? ? if( buffer )
? ? ? ? free( buffer );
? ? return rtn;
}

//jchar ->char
char jchartochar( jchar c )
{
? ? char ch = (char)(c & 0x00ff);
? ? return ch;
}

//char* ->jchar
jchar charTojchar( char c )
{
? ? jchar ch = (jchar)(c | 0xff00);
? ? return ch;
}

//char ->C#
System::Char chartoChar( char c )
{
? ? System::Char C = (System::Char)((int)(c));
? ? return C;
}

//C#->char
char Chartochar( System::Char c )
{
? ? char C = (char)((int)(c));
? ? return C;
}