Question

我从无参数构造函数类派生一个类，如下所示：

public class Base
{
    public Base(Panel panel1)
    {

    }
}

public class Derived : Base
{
    public Derived() : base(new Panel())
    {
        //How do I use panel1 here?
    }
}

如何在Derived中引用panel1？

（欢迎简单的解决方法。）

Answer 1

Adil的回答假定您可以修改Base。如果你不能，你可以这样做：

public class Derived : Base
{
    private Panel _panel;

    public Derived() : this(new Panel()) {}

    private Derived(Panel panel1) : base(panel1)
    {
        _panel = panel1;
    }
}

Answer 2

您需要在Panel中定义Base，您也可以使用受保护的代替public。阅读更多aboud access speicifiers here

public class Base
{
    public Panel panel {get; set;};
    public Base(Panel panel1)
    {
         panel = panel1;
    }
}


public class Derived : Base
{
    public Derived() : base(new Panel())
    {
          //  this.panel
    }
}

Answer 3

两种方式：

public class Derived : Base
{
    Panel aPanel;

    public Derived() : this(new Panel()) {}

    public Derived(Panel panel) : base(aPanel)
    {
        //Use aPanel Here.
    }
}

OR

public class Base
{
    protected Panel aPanel;

    public Base(Panel panel1)
    {
        aPanel = panel1
    }
}

Answer 4

public class Base
{
    // Protected to ensure that only the derived class can access the _panel attribute
    protected Panel _panel;
    public Base(Panel panel1)
    {
        _panel = panel1;
    }
}

public class Derived : Base
{
    public Derived() : base(new Panel())
    {
        // refer this way: base.panel
    }
}

此外，如果您只想为派生类提供get而不是set，则可以执行以下操作：

 public class Base
    {
        // Protected to ensure that only the derived class can access the _panel attribute
        private Panel _panel;
        public Base(Panel panel1)
        {
            _panel = panel1;
        }

        protected Panel Panel
        {  get { return _panel; } } 
    }

    public class Derived : Base
    {
        public Derived() : base(new Panel())
        {
            // refer this way: base.Panel (can only get)
        }
    }

如何获得基类的“新”参数？

4 个答案: