Question

假设我们有一个纯虚拟C ++类：

class INativeInterface {
public:
    virtual ~INativeInterface () {};
    virtual LPCWSTR GetString () = 0;
};

然后我们需要在C ++ / CLI中提供此接口的实现：

class HalfManagedImplementation : public INativeInterface {
public:
    virtual LPCWSTR GetString () override {
        // need to return wchar_t const * pointer which points to the 
        // data of our managedData string
        // pin_ptr is not suitable as it will go out of scope
        // what other options do we have here?
        // perhaps copying managed string contents to unmanaged heap?
        wchar_t * unmanagedString = new wchar_t [managedData->Length + 1];
        pin_ptr<const wchar_t> pinnedString = PtrToStringChars (managedData);
        wcscpy_s (unmanagedString, managedData->Length + 1, pinnedString);
        return unmanagedString;
    }
private:
    String^ managedData;
    void SetString (String^ param){
        // do something in .net
        managedData = param;
    }
};

我的主要问题是：

我是否可以在CRT堆上分配一个本机字符串，并将指针返回给本机C ++代码，就像我上面所做的那样，托管代码分配的内存将由本机代码取消分配？用法示例：

LPCWSTR data = cppCliObject->GetString (); // do stuff with returned data or persist it by copying it somewhere else delete[] data;
当本机C ++代码与C ++ / CLI代码不同时，第一个点是否有效？
将wchar_t数据返回到本机C ++时还有其他替代方法或最佳实践吗？

将wchar_t *从C ++ / CLI返回到native

0 个答案: