线程之间的回调同步

Question

我想等待GetValues.Get方法并同步返回值给调用者。ServerDataProvider、BookDataFetcher类是mycode的外部类，我无法控制它们。任何关于如何实现这一目标的帮助都将不胜感激。

namespace Test {
class Program
{
    static void Main(string[] args)
    {
        GetValues val = new GetValues();
        val.Get("BOOKS", DataHandler);
        Console.ReadKey();
    }
    static void DataHandler(IList<string> values) {
    }
}
class GetValues
{
    public delegate void DataHandler(IList<string> values);
    public event DataHandler OnReceiveDataHandler;
    public void Get(string colName, DataHandler handler)
    {
        OnReceiveDataHandler += handler;
        GetDataFromServer svr = new GetDataFromServer();
        svr.OnReceiveDataHandler += OnReceiveData;
        svr.GetData(colName);
    }
    // Callback Handler
    private void OnReceiveData(IList<string> values) {
        OnReceiveDataHandler(values);
    }
}
class GetDataFromServer
{
    internal delegate void DataHandler(IList<string> values);
    internal event DataHandler OnReceiveDataHandler;
    internal void GetData(string columnName)
    {
        ServerDataProvider datafetcher = new ServerDataProvider();
        datafetcher.OnReceiveDataHandler += OnReceiveData;
        Task.Factory.StartNew(() => datafetcher.GetDataFromServer(columnName));
    }
    // Callback Handler
    private void OnReceiveData(IList <string> values) {
        OnReceiveDataHandler(values);
    }
}
class ServerDataProvider
{
    internal delegate void DataHandler(IList<string> values);
    internal event DataHandler OnReceiveDataHandler;
    public void GetDataFromServer(string columnName)
    {
        BookDataFetcher b = new BookDataFetcher();
        b.OnReceiveDataHandler += OnReceiveData;
        Task.Factory.StartNew(() => b.GetBookData(columnName));
    }
    // Calback Handler
    private void OnReceiveData(IList<string> values)
    {
        OnReceiveDataHandler(values);
    }
}
class BookDataFetcher
{
    internal delegate void DataHandler(IList<string> values);
    internal event DataHandler OnReceiveDataHandler;
    public void GetBookData(string col)
    {
        Thread.Sleep(5000);
        OnReceiveDataHandler(new List<string> {"Book1", "Book2"});
    }
}

}

Answer 1

您所要求的可以使用MethodImplAttribute 实现

 [MethodImplAttribute(MethodImplOptions.Synchronized)] 
 public void MethodA()