C# virtual 这个关键字

最新推荐文章于 2025-03-30 17:06:12 发布

转载最新推荐文章于 2025-03-30 17:06:12 发布 · 221 阅读

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原文链接：http://www.cnblogs.com/systembighunter/p/7112797.html

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#c#

本文介绍了C#中如何使用virtual关键字来声明可以被派生类覆盖的方法、属性、索引器或事件，并提供了具体的代码示例。同时强调了virtual不能与static、abstract、private或override修饰符同时使用。

The virtual keyword is used to modify a method, property, indexer, or event declaration and allow for it to be overridden in a derived class. For example, this method can be overridden by any class that inherits it:

public virtual double Area()   
{  
    return x * y;  
}

You cannot use the virtual modifier with the static, abstract, private, or override modifiers. The following example shows a virtual property:

class MyBaseClass
{
    // virtual auto-implemented property. Overrides can only
    // provide specialized behavior if they implement get and set accessors.
    public virtual string Name { get; set; }

    // ordinary virtual property with backing field
    private int num;
    public virtual int Number
    {
        get { return num; }
        set { num = value; }
    }
}


class MyDerivedClass : MyBaseClass
{
    private string name;

   // Override auto-implemented property with ordinary property
   // to provide specialized accessor behavior.
    public override string Name
    {
        get
        {
            return name;
        }
        set
        {
            if (value != String.Empty)
            {
                name = value;
            }
            else
            {
                name = "Unknown";
            }
        }
    }

}

转载于:https://www.cnblogs.com/systembighunter/p/7112797.html