c# - 字典在后台加载

Question

这似乎应该如此简单，但显然并非如此。

我有一本字典需要在程序启动时加载大约 40,000 个条目。它只会延迟加载时间大约 5-7 秒，但我想在后台执行此操作以避免这种情况。

在下面的代码中，有 3 个部分处理我目前拥有的 dictionary 和 BackgroundWorker。

我知道这段代码进入了 PopulateZipCodeDictionary() 方法，但由于某种原因它实际上并没有启动该方法。

我做错了什么？

    static BackgroundWorker populateZipCodeDictionary;

    public MainWindow()
    {
        populateZipCodeDictionary = new BackgroundWorker();
        populateZipCodeDictionary.DoWork += populateZipCodeDictionary_DoWork;
        populateZipCodeDictionary.RunWorkerCompleted += populateZipCodeDictionary_RunWorkerCompleted;
        populateZipCodeDictionary.RunWorkerAsync();         
    }

    static void populateZipCodeDictionary_DoWork(object sender, DoWorkEventArgs e)
    {
        ZipCodes.PopulateZipCodeDictionary();
    }

    static void populateZipCodeDictionary_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
    {
        MessageBox.Show("Dictionary loaded");
    }

---

static class ZipCodes
{
    #region Methods
    public static string GetValue(string key)
    {
        string result;
        if (zipCodeDictionary.TryGetValue(key, out result))
        {
            return result;
        }
        else
        {
            return null;
        }
    }
    #endregion


    #region ZipCode Dictionary Definition
    static Dictionary<string, string> zipCodeDictionary = new Dictionary<string, string>();

    public static void PopulateZipCodeDictionary()
    {
        zipCodeDictionary.Add( "00501", "Holtsville, NY" );
        zipCodeDictionary.Add( "00544", "Holtsville, NY" );
        zipCodeDictionary.Add( "00601", "Adjuntas, PR" );
        zipCodeDictionary.Add( "00602", "Aguada, PR" );
        zipCodeDictionary.Add( "00603", "Aguadilla, PR" );
        zipCodeDictionary.Add( "00604", "Aguadilla, PR" );
        //Continues on adding ~40k entries...
    }

Answer 1

这是我用于后台处理的例程。您只需为 RunBehind 提供一个要执行的操作和一个在处理完成时调用的操作。

public class Worker
{
    private Dispatcher _appDispatcher = Dispatcher.CurrentDispatcher;
    private Dispatcher _workerDispatcher;
    private Thread _workerThread;

    public Worker()
    {
        _workerThread = new Thread(RunWorkerThread);
        _workerThread.Start();
    }

    public void RunBehind(Action a_action, Action a_callback)
    {
        _workerDispatcher.BeginInvoke(new Action(() =>
        {
            a_action();
            _appDispatcher.BeginInvoke(a_callback);
        }));
    }

    private void RunWorkerThread()
    {
        Thread.CurrentThread.Name = "AppWorker";
        _workerDispatcher = Dispatcher.CurrentDispatcher;

        Dispatcher.Run();
    }
}

也可能尝试锁定...

static class ZipCodes
{
    private static Object zipLocker = new Object();

    #region Methods
    public static string GetValue(string key)
    {
        lock (zipLocker)
        {
            string result;
            if (zipCodeDictionary.TryGetValue(key, out result))
            {
                return result;
            }
            else
            {
                return null;
            }
        }
    }
    #endregion


    #region ZipCode Dictionary Definition
    static Dictionary<string, string> zipCodeDictionary = null;

    public static void PopulateZipCodeDictionary()
    {
        Dictionary<string, string> workingDictionary = new Dictionary<string, string>();

        workingDictionary.Add( "00501", "Holtsville, NY" );
        workingDictionary.Add( "00544", "Holtsville, NY" );
        workingDictionary.Add( "00601", "Adjuntas, PR" );
        workingDictionary.Add( "00602", "Aguada, PR" );
        workingDictionary.Add( "00603", "Aguadilla, PR" );
        workingDictionary.Add( "00604", "Aguadilla, PR" );
        //Continues on adding ~40k entries...

        lock (zipLocker)
        {
            zipCodeDictionary = workingDictionary;
        }
    }
}