C#中的混凝土二传手抽象吸气剂

Question

我正在尝试为实现的只读集合编写一个抽象基类IList.这样的基类应该实现set-indexer来抛出a NotSupportedException,但是将get-indexer保留为abstract.C#是否允许这种情况？这是我到目前为止所拥有的:

public abstract class ReadOnlyList : IList {

    public bool IsReadOnly { get { return true; } }

    public object this[int index] {
        get {
            // there is nothing to put here! Ideally it would be left abstract.
            throw new NotImplementedException();
        }
        set {
            throw new NotSupportedException("The collection is read-only.");
        }
    }

    // other members of IList ...
}

理想情况下ReadOnlyList,能够实现setter,但保留getter摘要.有没有允许这个的语法？

Answer 1

将工作委派给受保护的成员,然后根据所需的行为将其标记为抽象或虚拟.尝试这样的事情:

 // implementor MUST override
 protected abstract object IndexerGet(int index);

 // implementor can override if he wants..
 protected virtual void IndexerSet(int index, object value) 
 {
   throw new NotSupportedException("The collection is read-only.");
 }

 public object this[int index] {
   get {
     return IndexerGet(index);
   }
   set {
     IndexerSet(index, value);
   }
 }