c# - WPF MVVM中用于数据库事务的任务，BackgroundWorkers或新线程？

Question

我有一个与数据库通信的小型MVVM应用程序。在后台线程中执行数据库事务的标准方法(如果有的话)是什么，当完成时会更新UI？我应该使用BackgroundWorkers，TPL还是实现自己的线程？目前，我有一个静态类，具有以下用于后台工作的方法:

public static void RunAsync(Action backgroundWork, Action uiWork, Action<Exception> exceptionWork) {

    var uiContext = TaskScheduler.FromCurrentSynchronizationContext();

    // The time consuming work is run on a background thread.
    var backgroundTask = new Task(() => backgroundWork());

    // The UI work is run on the UI thread.
    var uiTask = backgroundTask.ContinueWith(_ => { uiWork(); },
        CancellationToken.None,
        TaskContinuationOptions.OnlyOnRanToCompletion,
        uiContext);

    // Exceptions in the background task are handled on the UI thread.
    var exceptionTask = backgroundTask.ContinueWith(t => { exceptionWork(t.Exception); },
        CancellationToken.None,
        TaskContinuationOptions.OnlyOnFaulted,
        uiContext);

    // Exceptions in the UI task are handled on on the UI thread.
    var uiExceptionTask = uiTask.ContinueWith(t => { exceptionWork(t.Exception); },
        CancellationToken.None,
        TaskContinuationOptions.OnlyOnFaulted,
        uiContext);

    backgroundTask.Start();
}

Answer 1

您可以使用async/await，这将为您提供更自然的语法:

public static async Task RunAsync(Action backgroundWork, Action uiWork, Action<Exception> exceptionWork)
{
  try
  {
    // The time consuming work is run on a background thread.
    await Task.Run(backgroundWork);

    // The UI work is run on the UI thread.
    uiWork();
  }
  catch (Exception ex)
  {
    // Exceptions in the background task and UI work are handled on the UI thread.
    exceptionWork(ex);
  }
}

或更好的方法是，将RunAsync替换为代码本身，而不是

T[] values;
RunAsync(() => { values = GetDbValues(); }, () => UpdateUi(values), ex => UpdateUi(ex));

你可以说:

try
{
  var values = await Task.Run(() => GetDbValues());
  UpdateUi(values);
}
catch (Exception ex)
{
  UpdateUi(ex);
}