Question

我有一个嵌套私有类的以下类，我想将NID的值赋给Context。我使用了getter和setter，但NID（Sequencer.Context = value;）的值永远不会被分配给（SeqNode = Node.LoadNode(Context);）。我做错了什么？

//Instantiation
Increment.NID = "/Root/Dir/NodetoIncrement";
String getSequence = Convert.ToString(Increment.SID);

// The Class
public static class Increment
{
    //Value of the node Context location in the tree to increment ( Increment.NID )
    public static string NID
    {
        set { Sequencer.Context = value; } //The "/Root/Dir/NodetoIncrement";
    }

    //Get the sequence ID
    public static int SID
    {
        get { return Sequencer.GetSeqId; }
    }

    //Nested sequencer class. This increments the node.

    private class Sequencer
    {   
        private Node SeqNode;
        private static int SequenceNumber;
        private volatile bool Run = true;

        public static string Context { get; set; } //gets 

        public static int GetSeqId
        {
            get
            {
                return Interlocked.Add(ref SequenceNumber, 1);
            }
        }

        public Sequencer() //Constructor Here!
        {
            SeqNode = Node.LoadNode(Context);
            SequenceNumber = Convert.ToInt16(SeqNode["LastSequenceNo"]);

            //NEVER DO THIS .. causes the system to lockup see comments.
            System.Threading.Tasks.Task.Factory.StartNew(() =>
            {
                while (Run)
                {
                    Save();
                    Thread.Sleep(5000);
                }
            });
        }

        private void Save()
        {
            //optimistic concurrency recommended!!
            var retryMaxCount = 3;             // maximum number of attempts
            var cycles = 0;                    // current attempt
            Exception exception = null;        // inner exception storage
            while (cycles++ < retryMaxCount)   // cycle control
            {
                try
                {
                    SeqNode["LastSequenceNo"] = Convert.ToString(SequenceNumber);
                    SeqNode.Save();

                    // successful save, exit loop
                    exception = null;
                    break;
                }
                catch (NodeIsOutOfDateException e)
                {
                    exception = e; // storing the exception temporarily
                    SeqNode = Node.LoadNode(Context);
                }
            }
            // rethrow if needed
            if (exception != null)
                throw new ApplicationException("Node is out of date after 3 attempts.", exception);
        }


        ~Sequencer() { Save(); }

    }
}

public class XYHandler : Node
{
    public override void Save(NodeSaveSettings settings)
    {
        base.Name = Convert.ToString(Increment.SID);
        base.Save();
    }

    public override bool IsContentType
    {
        get { return true; }
    }
}

Answer 1

我做错了什么？

您正在等待静态初始化程序中的另一个线程。 从不这样做。我不能强烈地强调这是多么疯狂的危险。

要解释原因，请参阅此答案：

https://stackoverflow.com/a/8883117/88656

Answer 2

这里有一些时间耦合吗？

实例SeqNode时设置

Sequencer，但我无法在您的示例中看到实例化。

静态构造函数将在第一次调用属性setter之前运行，然后在5s之后再次尝试 - 属性何时被设置？

Answer 3

我无法看到Sequencer的构建位置（也许我错过了它）。由于它不是静态构造函数，因此必须至少调用一次才能运行LoadNode。你是否打算让那个构造函数也是静态的？

如何在私有嵌套类中设置私有字段的值？

3 个答案: