c# - 根据基本定义初始化子类

抱歉，这是一个常见问题，但是我花了相当长的时间搜索答案，却找不到确切的答案。

我有一个抽象类，其中包含其他抽象类（的定义）的字段。然后将这些用于属性的具体实现。但是，当我想初始化该抽象类的实现时，我希望用这些字段的特定实现填充这些字段。甚至对于我自己来说，这听起来确实令人困惑，因此这里是示例。

// My main abstract class
public abstract class Log
{
    public virtual bool AppendLog
    {
        set { _logWriter.Append = value; }
    }

    internal LogWriter _logWriter; //LogWriter is another abstract class

    public abstract void AddEntry(string input);
}

// Implementation of abstract class
public class SyncLog : Log
{
    public SyncLog
    {
        // Now I want to initialize LogWriter abstract class in parent with
        // It's actual implementation SyncLogWriter : LogWriter
        _logWriter = new SyncLogWriter();
    }

    public override void AddEntry(string input)
    {
        content.AddEntry(input);
        _logWriter.Write("Hello");
    }
}

尽管从技术上讲这是合规的，甚至可行，但是仍然存在问题。使用_logWriter时，我只能访问在抽象类LogWriter中声明的方法和属性，而不能访问在其子级（SyncLogWriter）中额外实现的方法和属性。虽然从技术上讲这很有意义，但我想知道是否有任何方法可以执行类似的方法，但是要使SyncLogWriter中所有可用的其他东西都可用吗？

最佳答案

在继承的类_syncLogWriter上使用其他成员SyncLog。
同样，最好通过构造函数为基类初始化_logWriter成员并将其设为私有。

// My main abstract class
public abstract class Log
{
    protected Log(LogWriter logWriter)
    {
        _logWriter = logWriter;
    }

    public virtual bool AppendLog
    {
        set { _logWriter.Append = value; }
    }

    private LogWriter _logWriter; //LogWriter is another abstract class

    public abstract void AddEntry(string input);
}

// Implementation of abstract class
public class SyncLog : Log
{
    private SyncLogWriter _syncLogWriter

    public SyncLog() : this(new SyncLogWriter()) { }

    private SyncLog(SyncLogWriter logWriter) : base(logWriter)
    {
        _syncLogWriter = logWriter;
    }

    public override void AddEntry(string input)
    {
        content.AddEntry(input);
        _syncLogWriter.Write("Hello");
    }
}