问题描述
我正在尝试将我的 .net framework 4.7.2 项目从 System.Reactive 4.4 升级到 5.0。但是，似乎 dispatcherScheduler 和将 dispatcher 转换为 IScheduler 的扩展方法都在这两个版本之间消失了。它们已经过时了吗？转移到不同的包？
解决方法
在这篇文章中讨论过： https://github.com/dotnet/reactive/issues/1423
基本上解决方案是目标框架：
<TargetFramework>net5.0-windows10.0.19041</TargetFramework>
这对我来说不是一个好的解决方案，所以我在我的项目中复制了旧的 DispatcherScheduler（使用 C#9）：
using System.Reactive.Disposables;
using System.Threading;
namespace System.Reactive.Concurrency
{
/// <summary>
/// Represents an object that schedules units of work on a <see cref="System.Windows.Threading.Dispatcher"/>.
/// </summary>
/// <remarks>
/// This scheduler type is typically used indirectly through the <see cref="Linq.DispatcherObservable.ObserveOnDispatcher{TSource}(IObservable{TSource})"/> and <see cref="Linq.DispatcherObservable.SubscribeOnDispatcher{TSource}(IObservable{TSource})"/> methods that use the Dispatcher on the calling thread.
/// </remarks>
public class DispatcherScheduler : LocalScheduler,ISchedulerPeriodic
{
/// <summary>
/// Gets the scheduler that schedules work on the <see cref="System.Windows.Threading.Dispatcher"/> for the current thread.
/// </summary>
public static DispatcherScheduler Current
{
get
{
var dispatcher = System.Windows.Threading.Dispatcher.FromThread(Thread.CurrentThread);
if (dispatcher == null)
{
throw new InvalidOperationException("NO_DISPATCHER_CURRENT_THREAD");
}
return new DispatcherScheduler(dispatcher);
}
}
/// <summary>
/// Constructs a <see cref="DispatcherScheduler"/> that schedules units of work on the given <see cref="System.Windows.Threading.Dispatcher"/>.
/// </summary>
/// <param name="dispatcher"><see cref="DispatcherScheduler"/> to schedule work on.</param>
/// <exception cref="ArgumentNullException"><paramref name="dispatcher"/> is <c>null</c>.</exception>
public DispatcherScheduler(System.Windows.Threading.Dispatcher dispatcher)
{
Dispatcher = dispatcher ?? throw new ArgumentNullException(nameof(dispatcher));
Priority = System.Windows.Threading.DispatcherPriority.Normal;
}
/// <summary>
/// Constructs a <see cref="DispatcherScheduler"/> that schedules units of work on the given <see cref="System.Windows.Threading.Dispatcher"/> at the given priority.
/// </summary>
/// <param name="dispatcher"><see cref="DispatcherScheduler"/> to schedule work on.</param>
/// <param name="priority">Priority at which units of work are scheduled.</param>
/// <exception cref="ArgumentNullException"><paramref name="dispatcher"/> is <c>null</c>.</exception>
public DispatcherScheduler(System.Windows.Threading.Dispatcher dispatcher,System.Windows.Threading.DispatcherPriority priority)
{
Dispatcher = dispatcher ?? throw new ArgumentNullException(nameof(dispatcher));
Priority = priority;
}
/// <summary>
/// Gets the <see cref="System.Windows.Threading.Dispatcher"/> associated with the <see cref="DispatcherScheduler"/>.
/// </summary>
public System.Windows.Threading.Dispatcher Dispatcher { get; }
/// <summary>
/// Gets the priority at which work items will be dispatched.
/// </summary>
public System.Windows.Threading.DispatcherPriority Priority { get; }
/// <summary>
/// Schedules an action to be executed on the dispatcher.
/// </summary>
/// <typeparam name="TState">The type of the state passed to the scheduled action.</typeparam>
/// <param name="state">State passed to the action to be executed.</param>
/// <param name="action">Action to be executed.</param>
/// <returns>The disposable object used to cancel the scheduled action (best effort).</returns>
/// <exception cref="ArgumentNullException"><paramref name="action"/> is <c>null</c>.</exception>
public override IDisposable Schedule<TState>(TState state,Func<IScheduler,TState,IDisposable> action)
{
if (action == null)
{
throw new ArgumentNullException(nameof(action));
}
var d = new SingleAssignmentDisposable();
Dispatcher.BeginInvoke(
new Action(() =>
{
if (!d.IsDisposed)
{
d.Disposable = action(this,state);
}
}),Priority
);
return d;
}
/// <summary>
/// Schedules an action to be executed after <paramref name="dueTime"/> on the dispatcher,using a <see cref="System.Windows.Threading.DispatcherTimer"/> object.
/// </summary>
/// <typeparam name="TState">The type of the state passed to the scheduled action.</typeparam>
/// <param name="state">State passed to the action to be executed.</param>
/// <param name="action">Action to be executed.</param>
/// <param name="dueTime">Relative time after which to execute the action.</param>
/// <returns>The disposable object used to cancel the scheduled action (best effort).</returns>
/// <exception cref="ArgumentNullException"><paramref name="action"/> is <c>null</c>.</exception>
public override IDisposable Schedule<TState>(TState state,TimeSpan dueTime,IDisposable> action)
{
if (action == null)
{
throw new ArgumentNullException(nameof(action));
}
var dt = Scheduler.Normalize(dueTime);
if (dt.Ticks == 0)
{
return Schedule(state,action);
}
return ScheduleSlow(state,dt,action);
}
private IDisposable ScheduleSlow<TState>(TState state,IDisposable> action)
{
var d = new MultipleAssignmentDisposable();
var timer = new System.Windows.Threading.DispatcherTimer(Priority,Dispatcher);
timer.Tick += (s,e) =>
{
var t = Interlocked.Exchange(ref timer,null);
if (t != null)
{
try
{
d.Disposable = action(this,state);
}
finally
{
t.Stop();
action = static (s,t) => Disposable.Empty;
}
}
};
timer.Interval = dueTime;
timer.Start();
d.Disposable = Disposable.Create(() =>
{
var t = Interlocked.Exchange(ref timer,null);
if (t != null)
{
t.Stop();
action = static (s,t) => Disposable.Empty;
}
});
return d;
}
/// <summary>
/// Schedules a periodic piece of work on the dispatcher,using a <see cref="System.Windows.Threading.DispatcherTimer"/> object.
/// </summary>
/// <typeparam name="TState">The type of the state passed to the scheduled action.</typeparam>
/// <param name="state">Initial state passed to the action upon the first iteration.</param>
/// <param name="period">Period for running the work periodically.</param>
/// <param name="action">Action to be executed,potentially updating the state.</param>
/// <returns>The disposable object used to cancel the scheduled recurring action (best effort).</returns>
/// <exception cref="ArgumentNullException"><paramref name="action"/> is <c>null</c>.</exception>
/// <exception cref="ArgumentOutOfRangeException"><paramref name="period"/> is less than <see cref="TimeSpan.Zero"/>.</exception>
public IDisposable SchedulePeriodic<TState>(TState state,TimeSpan period,Func<TState,TState> action)
{
if (period < TimeSpan.Zero)
{
throw new ArgumentOutOfRangeException(nameof(period));
}
if (action == null)
{
throw new ArgumentNullException(nameof(action));
}
var timer = new System.Windows.Threading.DispatcherTimer(Priority,Dispatcher);
var state1 = state;
timer.Tick += (s,e) =>
{
state1 = action(state1);
};
timer.Interval = period;
timer.Start();
return Disposable.Create(() =>
{
var t = Interlocked.Exchange(ref timer,null);
if (t != null)
{
t.Stop();
action = static _ => _;
}
});
}
}
}
尽管我的开发机器使用的是最新版本的 Windows 10，但它对我来说没有问题。