如何在vc ++中将'System :: String ^'转换为'const char *'?
我的代码:
String ^Result1= "C:/Users/Dev/Desktop/imag.jpg";
IplImage *img1 = cvLoadImage(Result1, 1);
如果我喜欢上面会产生以下错误。
error C2664: 'cvLoadImage' : cannot convert parameter 1 from 'System::String ^' to 'const char *'
请帮帮我。
答案 0 :(得分:12)
就像这样:How to convert from System::String* to Char* in Visual C++
System::String ^ str = "Hello world\n";
//method 1
pin_ptr<const wchar_t> str1 = PtrToStringChars(str);
wprintf(str1);
//method 2
char* str2 = (char*)Marshal::StringToHGlobalAnsi(str).ToPointer();
printf(str2);
Marshal::FreeHGlobal((IntPtr)str2);
//method 3
CString str3(str);
wprintf(str3);
//method 4
#if _MSC_VER > 1499 // Visual C++ 2008 only
marshal_context ^ context = gcnew marshal_context();
const char* str4 = context->marshal_as<const char*>(str);
puts(str4);
delete context;
#endif
答案 1 :(得分:3)
这对我有用。
void MarshalString ( String ^ s, string& os ) {
using namespace Runtime::InteropServices;
const char* chars =
(const char*)(Marshal::StringToHGlobalAnsi(s)).ToPointer();
os = chars;
Marshal::FreeHGlobal(IntPtr((void*)chars));
}