C++与.NET中基础类型的对应及转化
前言:为了介绍C#写界面，C++写算法的快捷交互开发方式，首先介绍c++，C#内部的DLL，COM调用.
一，基础类型
二，字符类型
/***
Author
-
Nishant SivakumarCopyright(C)
-
Nishant Sivakumar
2005
***/
#pragma once#include
<
wtypes.h
>
#include
<
vector
>
#include
<
string
>
#include
<
vcclr.h
>
using namespace System;using namespace System::Runtime::InteropServices;namespace StringUtilities{
//
Class StringConvertorBase
//
Serves
as
the abstract base class
for
StringConvertor
and
implements
//
default initialization
and
clean
-
up code. ref class StringConvertorBase abstract { protected: StringConvertorBase() { InternalInit(); } ~StringConvertorBase() { InternalCleanUp(); }
//
While
the finalizer
is
included
to
take care of cases
//
where the destructor does
not
get
called, it
'
s highly inefficient
//
and
ruins the purpose of the class
if
the class
is
not
used
//
with
deterministic destruction. It
'
s recommended that you either use
//
the auto
-
variable non
-
handle declaration format
or
explicitly
//
call
delete
on
the StringConvertor
object
after use. !StringConvertorBase() { InternalCleanUp();#ifdef _DEBUG throw gcnew Exception(
"
Finalizer should not have got called
"
);#
else
Diagnostics::Trace::WriteLine(
"
Finalizer should not have got called
"
);#endif } std::vector
<
gcroot
<
IntPtr
>
>*
m_vec_hglobal; std::vector
<
gcroot
<
IntPtr
>
>*
m_vec_bstr;
//
Frees the allocated unmanaged memory void InternalCleanUp() {
for
each
(gcroot
<
IntPtr
>
ptr in
*
m_vec_hglobal) { Marshal::FreeHGlobal(ptr); } m_vec_hglobal
->
clear(); delete m_vec_hglobal;
for
each
(gcroot
<
IntPtr
>
ptr in
*
m_vec_bstr) { Marshal::FreeBSTR(ptr); } m_vec_bstr
->
clear(); delete m_vec_bstr; } void InternalInit() { m_vec_hglobal
=
new
std::vector
<
gcroot
<
IntPtr
>
>
(); m_vec_bstr
=
new
std::vector
<
gcroot
<
IntPtr
>
>
(); } };
//
Class StringConvertor
//
General purpose convertor class
for
System::
String
(both from
and
to
) ref class StringConvertor : StringConvertorBase { protected:
String
^
m_String;
//
The internal System::
String
object
public
:
//
Various constructors
each
taking a different type
as
argument StringConvertor(
String
^
s) : m_String(s) {
if
(m_String
==
nullptr) throw gcnew Exception(
"
You need to pass a non-null String
"
); } StringConvertor(
const
char
*
s) {
if
(s
==
nullptr) throw gcnew Exception(
"
You need to pass a non-null char*
"
); m_String
=
gcnew
String
(s); } StringConvertor(
const
__wchar_t
*
s) {
if
(s
==
nullptr) throw gcnew Exception(
"
You need to pass a non-null __wchar_t*
"
); m_String
=
gcnew
String
(s); } StringConvertor(
array
<
Char
>^
s) {
if
(s
==
nullptr) throw gcnew Exception(
"
You need to pass a non-null Char array
"
); m_String
=
gcnew
String
(s); } StringConvertor(BSTR s) {
if
(s
==
nullptr) throw gcnew Exception(
"
You need to pass a non-null BSTR
"
); m_String
=
gcnew
String
(s); } StringConvertor(std::
string
s) { m_String
=
gcnew
String
(s.c_str()); } StringConvertor(std::wstring s) { m_String
=
gcnew
String
(s.c_str()); }
//
Methods virtual
String
^
ToString() override { return m_String; }
//
Operators operator
String
^
() { return m_String; }
//
Properties
//
Returns an interior pointer
to
the underlying
string
. The
//
pointer
is
of type
const
Char so you can only read through it.
property
interior_ptr
<
const
Char
>
InteriorConstCharPtr { interior_ptr
<
const
Char
>
get
() { return PtrToStringChars(m_String); } }
//
Returns an interior pointer
to
the underlying
string
that can be
//
written
to
. Use
with
extreme care,
as
you are directly editing the
//
System::
String
'
s internal character buffer.
property
interior_ptr
<
Char
>
InteriorCharPtr { interior_ptr
<
Char
>
get
() { return const_cast
<
interior_ptr
<
Char
>
>
(InteriorConstCharPtr); } }
//
Generic character mapping
to
use
with
LPTSTR.
//
Since it
'
s a #define, intellisense won't show it.
#ifdef _UNICODE #define NativeTCharPtr NativeWideCharPtr#
else
#define NativeTCharPtr NativeCharPtr#endif
//
Returns a char
*
(allocated
on
the native heap)
property
char
*
NativeCharPtr { char
*
get
() { IntPtr ptr
=
Marshal::StringToHGlobalAnsi(m_String);
if
(ptr !
=
IntPtr::Zero) { m_vec_hglobal
->
push_back(ptr); return reinterpret_cast
<
char
*>
(static_cast
<
void
*>
(ptr)); }
else
return nullptr; } }
//
Returns a __wchar_t
*
(allocated
on
the native heap)
property
__wchar_t
*
NativeWideCharPtr { __wchar_t
*
get
() { IntPtr ptr
=
Marshal::StringToHGlobalUni(m_String);
if
(ptr !
=
IntPtr::Zero) { m_vec_hglobal
->
push_back(ptr); return reinterpret_cast
<
__wchar_t
*>
(static_cast
<
void
*>
(ptr)); }
else
return nullptr; } }
//
Returns a CLI
array
of Chars
property
array
<
Char
>^
CharArray {
array
<
Char
>^
get
() { return m_String
->
ToCharArray(); } }
//
Returns a BSTR allocated natively (unmanaged heap)
property
BSTR BSTRCopy { BSTR
get
() { IntPtr ptr
=
Marshal::StringToBSTR(m_String);
if
(ptr !
=
IntPtr::Zero) { m_vec_bstr
->
push_back(ptr); return reinterpret_cast
<
BSTR
>
(static_cast
<
void
*>
(ptr)); }
else
return nullptr; } }
//
Returns an std::
string
object
property
std::
string
STLAnsiString { std::
string
get
() { IntPtr ptr
=
Marshal::StringToHGlobalAnsi(m_String);
if
(ptr !
=
IntPtr::Zero) { std::
string
tmp(reinterpret_cast
<
char
*>
(static_cast
<
void
*>
(ptr))); Marshal::FreeHGlobal(ptr); return tmp; } return std::
string
(); } }
//
Returns an std::wstring
object
property
std::wstring STLWideString { std::wstring
get
() { IntPtr ptr
=
Marshal::StringToHGlobalUni(m_String);
if
(ptr !
=
IntPtr::Zero) { std::wstring tmp(reinterpret_cast
<
__wchar_t
*>
(static_cast
<
void
*>
(ptr))); Marshal::FreeHGlobal(ptr); return tmp; } return std::wstring(); } } };}
三，其他
对于COM，在托管代码和非托管代码之间进行的所有调用都必须满足各自编程模型强加的要求。托管和非托管编程模型在很多方面是不同的。下表显示了每个模型的定义特征。
特征 非托管模型 托管模型 代码模型
基于接口
基于对象
标识
GUID
强名称
错误处理机制
HRESULT
异常
类型兼容性
二进制标准
类型标准
类型定义
类型库
元数据
类型安全
非类型安全
可选安全
版本控制
不可变的
灵活的
COM类型对应：
COM 值类型 COM 引用类型 系统类型 bool
bool *
System.Int32
char、small
char *、small *
System.SByte
short
short *
System.Int16
long、int
long *、int *
System.Int32
Hyper
hyper *
System.Int64
unsigned char、byte
unsigned char *、byte *
System.Byte
wchar_t、unsigned short
wchar_t *、unsigned short *
System.UInt16
unsigned long、unsigned int
unsigned long *、unsigned int *
System.UInt32
unsigned hyper
unsigned hyper *
System.UInt64
float
float *
System.Single
double
double *
System.Double
VARIANT_BOOL
VARIANT_BOOL *
System.Boolean
void*
void **
System.IntPtr
HRESULT
HRESULT *
System.Int16 或 System.IntPtr
SCODE
SCODE *
System.Int32
BSTR
BSTR *
System.String
LPSTR 或 [string, ...] char *
LPSTR *
System.String
LPWSTR 或 [string, …] wchar_t *
LPWSTR *
System.String
VARIANT
VARIANT *
System.Object
DECIMAL
DECIMAL *
System.Decimal
DATE
DATE *
System.DateTime
GUID
GUID *
System.Guid
CURRENCY
CURRENCY *
System.Decimal
IUnknown *
IUnknown **
System.Object
IDispatch *
IDispatch **
System.Object
SAFEARRAY( type )
SAFEARRAY( type ) *
type []
四，参考：
http://www.codeproject.com/managedcpp/StringConvertor.asp
http://www.voidnish.com/articles/ShowArticle.aspx?code=StringConvertor
