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从System::String^到const wchar\t的字符串转换*_String_C++ Cli_Widechar - Fatal编程技术网

从System::String^到const wchar\t的字符串转换*

从System::String^到const wchar\t的字符串转换*,string,c++-cli,widechar,String,C++ Cli,Widechar,我试图使用字符串参数打开文件,但出现以下错误: error C2664: 'void std::basic_ifstream<_Elem,_Traits>::open(const wchar_t *,std::ios_base::openmode,int)' : cannot convert parameter 1 from 'System::String ^' to 'const wchar_t *' 错误C2664:'void std::basic_ifstream::open

我试图使用字符串参数打开文件,但出现以下错误:

error C2664: 'void std::basic_ifstream<_Elem,_Traits>::open(const wchar_t *,std::ios_base::openmode,int)' : cannot convert parameter 1 from 'System::String ^' to 'const wchar_t *'
错误C2664:'void std::basic_ifstream::open(const wchar\u t*,std::ios\u base::openmode,int)':无法将参数1从'System::String^'转换为'const wchar\u t*'

如何将
System::String^
转换为
const wchar\u t*

正如Hans指出的,简单的转换是必要的。它看起来类似于以下内容:

System::String ^str = L"Blah Blah";
pin_ptr<const wchar_t> convertedValue = PtrToStringChars(str);  // <-- #include <vcclr.h>
const wchar_t *constValue = convertedValue;                     // <-- Unnecessary, but to be completely verbose
void std::basic_ifstream<_Elem, _Traits>::open(constValue, mode, i);
System::String^str=L“诸如此类”;

pin_ptr convertedValue=PtrToStringChars(str);// 正如汉斯指出的,简单的转换是必要的。它看起来类似于以下内容:

System::String ^str = L"Blah Blah";
pin_ptr<const wchar_t> convertedValue = PtrToStringChars(str);  // <-- #include <vcclr.h>
const wchar_t *constValue = convertedValue;                     // <-- Unnecessary, but to be completely verbose
void std::basic_ifstream<_Elem, _Traits>::open(constValue, mode, i);
System::String^str=L“诸如此类”;

pin_ptr convertedValue=PtrToStringChars(str);//对文件路径以UTF-16编码
PtrToStringChars
pin_ptr
也适用于此,因为.NET字符串也是UTF-16。是的!文件路径以UTF-16编码
PtrToStringChars
pin_ptr
也适用于此,因为.NET字符串也是UTF-16。