如何访问继承类中的受保护成员

Question

我有2个班:

public class Access
{
    public class Job
    {
        public int Id { get; set; }
        protected string JobName { get; set; }
    }
}

Class2.cs

public class Full: Access.Job
{

}

Full ful = new Full();

为什么我无法访问该ful.JobName会员？

Answer 1

因为您正在尝试从类外部访问受保护的方法.只有公共方法可用.您可以访问受保护的属性/ variably /方法,仅在继承的类中,但不能从外部代码访问:

public class Full: Access.Job
{
    public void mVoid()
    {
        Console.WriteLine(this.JobName);
    }

    protected void mProtVoid()
    {
        Console.WriteLine(this.JobName);
    }

    private void mPrivateVoid()
    {
        Console.WriteLine("Hey");
    }
}

Full myFull = new Full();
myFull.mVoid();  //will work
myFull.mProtVoid(); //Will not work
myFull.mPrivateVoid(); //Will not work

如果您需要访问受保护的属性,有两种方法(实际上有3种方式,但反射是脏的方式,应该避免):

1.公开

如果它将设置为public,它将是stil继承,您可以直接访问它:

Full nFull = new Full();
Console.Write(nFull.JobName);

2.做一个"包装"/"门面"

创建新属性或方法,只访问隐藏属性并以预期格式返回.

public class Full: Access.Job
{
    public string WrappedJobName { get { return this.JobName; } }
    public string WrappedJobName => this.JobName; //C# 6.0 syntax
}

Full mFull = new Full();
Console.WriteLine(mFull.WrappedJobName);