Question

To convert from a system::String to an std::string, I use the following code:

IntPtr p = Marshal::StringToHGlobalAnsi(PORT);
string newString = static_cast<char*>(p.ToPointer());
Marshal::FreeHGlobal(p);

However, the place where I got the code uses

IntPtr p = Marshal::StringToHGlobalAnsi(PORT);
char* newString = static_cast<char*>(p.ToPointer());
Marshal::FreeHGlobal(p);

For some reason though, I get garbage in newString if I do the char* version. Anyone know why this would happen?

Thanks.

Answer 1

The reason the std::string version works is because it immediately creates a privatecopy of the char* value. This private copy is not affected by the later FreeHGlobal.

The char* version is assigned a pointer to memory which you then free on the very next line. It’s invalid the moment the FreeHGlobal command executes.