gcnew KeyEventHandler编译问题(VC++)

Question

我的托管 C++ 代码无法编译并显示错误消息

.\Window.cpp(11) : error C2440: 'initializing' : cannot convert from 'System::Windows::Forms::Form ^' to 'Enviroment::Window ^'
        No user-defined-conversion operator available, or
        Types pointed to are unrelated; conversion requires reinterpret_cast, C-style cast or function-style cast
.\Window.cpp(11) : error C3754: delegate constructor: member function 'Enviroment::Window::_keydown' cannot be called on an instance of type 'System::Windows::Forms::Form ^'

Error   1   error C2440: 'initializing' : cannot convert from 'System::Windows::Forms::Form ^' to 'Enviroment::Window ^'    c:\Users\Thomas\Documents\Visual Studio 2008\Projects\Project_X\Project_X\Window.cpp    11
Error   2   error C3754: delegate constructor: member function 'Enviroment::Window::_keydown' cannot be called on an instance of type 'System::Windows::Forms::Form ^'  c:\Users\Thomas\Documents\Visual Studio 2008\Projects\Project_X\Project_X\Window.cpp    11

In window.h

ref class Window
    {
    public:
        Window();
        void _keydown(System::Object^ sender, System::Windows::Forms::KeyEventArgs^ e);
    }

In window.cpp

Window::Window()
    {
        Form^ form = gcnew Form();
        form->KeyDown+= gcnew KeyEventHandler(form, &Window::_keydown);
}

及更高版本

void Window::_keydown(System::Object^ sender, System::Windows::Forms::KeyEventArgs^ e)
    {
        //stuff
    }

帮助！

Answer 1

我想你的意思是：

form->KeyDown+= gcnew KeyEventHandler(this, &Window::_keydown);

在C++中，类函数指针由两部分组成，实际指针（这部分你猜对了）和一个指向要传递给函数的“this”的指针，它的类型是持有该函数的类。这是您的Window，而不是Microsoft 的Form。