VS里面的类型转换

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1. string和char*

string转char* :

把string转换为char* 有3中方法：

1.data
如：

string str="abc";

char* p = (char*)str.data();

2.c_str
如：

string str ="gdfd";

char *p = str.c_str();

3. copy
如:

string str = "hello";

char p[40];

str.copy(p,5,0);

*(p+5)='\0';

char*转string

string转换为char*，可以使用string提供的函数c_str() ，或是函数data()，data除了返回字符串内容外，

不附加结束符'\0'，而c_str()返回一个以‘\0’结尾的字符数组.

2.CString和char*

cstring转char*

1. 宽字节时：

CString str1 = "123";

char *p = (LPSTR)(LPCSTR) str1; 强转

还可以：

CString str1 = "123";

char *t1 = str1.GetBuffer(str1.GetLength());

2.UNICODE

CString str1 = _T("123");

int len = WideCharToMultiByte(CP_ACP,0,str1,-1,NULL,0,NULL,NULL);

char *ptxtTemp = new char[len+1];

WideCharToMultiByte(CP_ACP,0,str1,-1,ptxtTemp,len,NULL,NULL);

//.......

delete[] ptxtTemp;

char*转CString

char *str="aaaa";

CString str1(str);

3.CString和string

CString转string

string s(CString.GetBuffer());

GetBuffer()后一定要ReleaseBuffer()，否则就没有释放缓冲区所占的空间

string转CString

CString.format("%s",string.c_str());

4.CString和int

CString转int

宽字节下：

CString str1="123";

int i = atoi(str1);

UNICODE:

CString str2 = _T("100");

int i;

swscanf(str2,_T("%d"),&i);

int转CString

int i = 100;

CString str;

str.Format("%d",i);

5.CString和LPCWSTR

CString转LPCWSTR

方法1：

CString strFileName;

LPCWSTR lpcwStr = strFileName.AllocSysString();

方法2：

CString str=_T("TestStr");

USES_CONVERSION;

LPCWSTR lpcwStr = A2CW((LPCSTR)str);

LPCWSTR转CString

LPCWSTR lpcwStr = L"TestWStr"; CString str(lpcwStr);

CString str;LPWSTR  lpstr = (LPWSTR)(LPCWSTR)str;

6.CString和LPSTR

CString转LPSTR

方法1：

CString strFileName;LPSTR lpStr = strFileName.GetBuffer();strFileName.ReleaseBuffer();

方法2：

LPSTR lpStr = (LPSTR)(LPCSTR)strFimeName;

LPSTR转CString

LPSTR lpStr = L"TestStr"; CString str(lpStr);

7.CString和BSTR

CString转BSTR

CString str;str = .....; // whateverBSTR bStr = str.AllocSysString();

BSTR转CString

UNICODE下：

CString convert(BSTR bStr){   if(bStr == NULL)        return CString(_T(""));   CString s(bStr); // in UNICODE mode    <span></span>return s;}

宽字节下：

CString convert(BSTR b){   CString s;    if(b == NULL)       <span style="white-space:pre"></span>return s; // empty for NULL BSTR#ifdef UNICODE    s = b;#else    LPSTR p = s.GetBuffer(SysStringLen(b) + 1);    ::WideCharToMultiByte(CP_ACP,            // ANSI Code Page                          0,                 // no flags                          b,                 // source widechar string                          -1,                // assume NUL-terminated                          p,                 // target buffer                          SysStringLen(b)+1, // target buffer length                          NULL,              // use system default char                          NULL);             // don''t care if default used    s.ReleaseBuffer();#endif    return s;}

8.char*和LPCWSTR

char*转LPCWSTR

1、通过MultiByteToWideChar函数转换 view plain co

char* szStr = "测试字符串";  WCHAR wszClassName[256];  memset(wszClassName,0,sizeof(wszClassName));  MultiByteToWideChar(CP_ACP,0,szStr,strlen(szStr)+1,wszClassName,  sizeof(wszClassName)/sizeof(wszClassName[0]));

2、通过T2W转换宏

char* szStr = "测试字符串";     CString str = CString(szStr);  USES_CONVERSION;  LPCWSTR wszClassName = new WCHAR[str.GetLength()+1];  wcscpy((LPTSTR)wszClassName,T2W((LPTSTR)str.GetBuffer(NULL)));  str.ReleaseBuffer();

3、通过A2CW转

char* szStr = "测试字符串";     CString str = CString(szStr);  USES_CONVERSION;  LPCWSTR wszClassName = A2CW(W2A(str));  str.ReleaseBuffer();

以上是在UNICODE状态下

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