[UWP] [C ++]创建自定义UIElement以添加到Canvas [英] [UWP][C++]Create custom UIElement to add to Canvas

问题描述

我有一个UWP应用程序，它在Windows :: UI :: Controls :: Canvas上绘制各种形状（椭圆，多边形，矩形）。 



我想创建一个继承自UIElement的自定义DrawingObject类（我想）。我想为这个  DrawingObject添加一些自定义字段，例如名称，描述等的字符串。

I have a UWP app that draws various shapes (Ellipse, Polygon, Rectangle) on a Windows::UI::Controls::Canvas. 

I would like to create a custom DrawingObject class that inherits from UIElement (I think). I would like to add some custom fields to this DrawingObject such as a Strings for name, description, etc.

我试图创建一个C ++ / CX类 

I have tried to create a C++/CX class 

public ref class DrawingObject sealed : UIElement
{
public:
DrawingObject();
private:
~DrawingObject();
};

但我收到错误 

But I get the error 

'Windows :: UI :: Xaml :: UIElement :: UIElement'：无法访问类'Windows :: UI :: Xaml :: UIElement'中声明的私有成员

'Windows::UI::Xaml::UIElement::UIElement': cannot access private member declared in class 'Windows::UI::Xaml::UIElement'

第一个问题是如何解决此错误？第二个问题是如何在这个DrawingObject中定义一个形状，以便它在画布上呈现？

First question is how to resolve this error? The second question is how do I define a shape within this DrawingObject so that it is rendered on the canvas?

推荐答案

Hello Oliver，

Hello Oliver,

请检查
UIElement doc 首先你会发现以下内容：

Please check the UIElement doc first and you will find the following:

UIElement不公开公共构造函数。通常，您不直接从UIElement或FrameworkElement派生类。派生自定义类的更常用基类是这些类：

UIElement does not expose a public constructor. Typically, you don't derive classes from either UIElement or FrameworkElement directly. More typically used base classes for derived custom classes are these classes:

•  未密封的特定控件（例如，TextBox）
•  控制基类（Control，ContentControl，UserControl）
  
  
•  导航元素（页面，框架）
•  面板类（基类Panel，或特定的非密封实现，如Grid）

对于您的特定方案，请尝试创建
UserControl 。

For your specific scenario, please try create a UserControl instead.

祝你好运，

Barry 

Barry 

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