为什么属性不能在ref类密封的情况下公开 [英] Why can properties not be public inside a ref class sealed

问题描述

以下代码是非法的(Visual Studio 2012 Windows Phone(创建Windows Phone Direct3d应用程序))

The following code is illegal ( Visual Studio 2012 Windows Phone( Creating a windows phone direct3d app ) )

a non-value type cannot have any public data members 'posX'

标题

ref class Placement sealed
{
public:
    Placement(
        float rotX, 
        float rotY, 
        float rotZ, 
        float posX, 
        float posY, 
        float posZ
    );
    float rotX, rotY, rotZ, posX, posY, posZ;
};

Cpp

Placement::Placement(
        float rotX, 
        float rotY, 
        float rotZ, 
        float posX, 
        float posY, 
        float posZ
    )
    :   posX( posX ),
        posY( posY ),
        posZ( posZ )
{
    this->rotX = static_cast<float>(rotX);
    this->rotY = static_cast<float>(rotY);
    this->rotZ = static_cast<float>(rotZ);
}

为什么以及如何设置属性?我已经习惯了普通的C ++，而不是C ++ CX(我认为这是正确的吗?)...我是否必须创建用于服务属性的方法?

*这个问题源于我本来试图创建一个普通类并创建一个指向它的指针，但只能抱怨我不能使用*，而不得不使用^，这意味着我必须创建一个ref类反而... 我真的不明白为什么?*

*This problem stemmed from me originally trying to create a normal class and creating a pointer to it, only to be complained to about the fact I cannot use * rather I have to use ^ which means I have to create a ref class instead... I don't really understand why?*

与WinRT或更具体地与ARM处理器有关吗?

推荐答案

这是WinRT和C ++/CX扩展所特有的. C ++/CX不允许引用类包含公共字段.您需要用公共属性替换公共字段.

This is something specific to WinRT and the C++/CX extensions specifically. C++/CX does not allow ref classes to contain public fields. You need to replace your public fields with public properties.

 ref class Placement sealed
{
public:
    Placement(
        float rotX, 
        float rotY, 
        float rotZ, 
        float posX, 
        float posY, 
        float posZ
    );
    property float rotX;
    property float rotY;
    property float rotZ;
    property float posX;
    property float posY;
    property float posZ;
};

属性具有由编译器自动生成的getter和setter函数.

Properties have getter and setter functions generated automatically for them by the compiler.

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