Eu sei que estou atrasado, acabei de mudar a forma como gerencio o cursor Hourglass (estado ocupado) do meu aplicativo.
Esta solução proposta é mais complexa do que minha primeira resposta, mas acho que é mais completa e melhor.
Eu não disse que tenho uma solução fácil ou completa. Mas, para mim, é o melhor porque principalmente corrige todos os problemas que tive ao gerenciar o estado de ocupado do meu aplicativo.
Vantagens:
- Pode gerenciar o estado "Ocupado" tanto do modelo quanto da visualização.
- Capaz de gerenciar o estado de ocupado, se não houver GUI. Desacoplado da GUI.
- Thread seguro (pode ser usado a partir de qualquer thread)
- Suportar substituição de ocupado (mostrar seta temporariamente) quando houver uma janela (diálogo) que deve ser visível no meio de uma transação muito longa.
- Capaz de empilhar muitas operações com comportamento ocupado que mostram uma ampulheta constante se fizer parte de muitas subtarefas pequenas e longas. Ter uma ampulheta que não mudasse frequentemente de ocupado para normal para ocupado. Um estado de ocupação constante, se possível, usando uma pilha.
- Suporta subscrição de evento com ponteiro fraco porque a instância de objeto "Global" é global (nunca será Garbage Collected - ele tem raiz).
O código é separado em algumas classes:
- Nenhuma classe GUI: "Global" que gerencia o estado Ocupado e deve ser inicializada no início do aplicativo com o despachante. Por ser global (singleton), optei por ter um evento NotifyPropertyChanged fraco para não manter uma referência rígida sobre ninguém que deseja ser notificado de qualquer alteração.
- Uma classe GUI: AppGlobal que se conecta a Global e muda a aparência do mouse de acordo com o estado Gloab.Busy. Deve ser inicializado com o despachante também no início do programa.
- Uma classe GUI para ajudar o Dialog (Window) a ter um comportamento adequado do mouse quando usado em uma transação longa onde o mouse foi sobrescrito para mostrar uma ampulheta e deseja a seta regular quando o Dialog (Window) está em uso.
- O código também inclui algumas dependências.
Este é o uso:
Iniciar:
public partial class App : Application
{
// ******************************************************************
protected override void OnStartup(StartupEventArgs e)
{
Global.Init(Application.Current.Dispatcher);
AppGlobal.Init(Application.Current.Dispatcher);
Uso preferido:
using (Global.Instance.GetDisposableBusyState())
{
...
}
Outro uso:
// ******************************************************************
public DlgAddAggregateCalc()
{
InitializeComponent();
Model = DataContext as DlgAddAggregateCalcViewModel;
this.Activated += OnActivated;
this.Deactivated += OnDeactivated;
}
// ************************************************************************
private void OnDeactivated(object sender, EventArgs eventArgs)
{
Global.Instance.PullState();
}
// ************************************************************************
private void OnActivated(object sender, EventArgs eventArgs)
{
Global.Instance.PushState(false);
}
Cursor da janela automática:
public partial class DlgAddSignalResult : Window
{
readonly WindowWithAutoBusyState _autoBusyState = new WindowWithAutoBusyState();
// ******************************************************************
public DlgAddSignalResult()
{
InitializeComponent();
Model = DataContext as DlgAddSignalResultModel;
_autoBusyState.Init(this);
}
Código:
// Copyright (c) 2008 Daniel Grunwald
//
// Permission is hereby granted, free of charge, to any person
// obtaining a copy of this software and associated documentation
// files (the "Software"), to deal in the Software without
// restriction, including without limitation the rights to use,
// copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following
// conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
// OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
// HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
// WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
// OTHER DEALINGS IN THE SOFTWARE.
/* Usage:
*
*
*
public delegate void FileChangedHandler(object sender, FileSystemEventArgs e);
[field: NonSerialized]
private readonly SmartWeakEvent<FileChangedHandler> _weakFileChanged = new SmartWeakEvent<FileChangedHandler>();
public event FileChangedHandler FileChanged
{
add
{
_weakFileChanged.Add(value);
}
remove
{
_weakFileChanged.Remove(value);
}
}
*
*
*/
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Reflection;
using System.Runtime.CompilerServices;
namespace HQ.Util.General.WeakEvent
{
/// <summary>
/// A class for managing a weak event.
/// </summary>
public sealed class SmartWeakEvent<T> where T : class
{
struct EventEntry
{
public readonly MethodInfo TargetMethod;
public readonly WeakReference TargetReference;
public EventEntry(MethodInfo targetMethod, WeakReference targetReference)
{
this.TargetMethod = targetMethod;
this.TargetReference = targetReference;
}
}
readonly List<EventEntry> eventEntries = new List<EventEntry>();
// EO: Added for ObservableCollectionWeak
public int CountOfDelegateEntry
{
get
{
RemoveDeadEntries();
return eventEntries.Count;
}
}
static SmartWeakEvent()
{
if (!typeof(T).IsSubclassOf(typeof(Delegate)))
throw new ArgumentException("T must be a delegate type");
MethodInfo invoke = typeof(T).GetMethod("Invoke");
if (invoke == null || invoke.GetParameters().Length != 2)
throw new ArgumentException("T must be a delegate type taking 2 parameters");
ParameterInfo senderParameter = invoke.GetParameters()[0];
if (senderParameter.ParameterType != typeof(object))
throw new ArgumentException("The first delegate parameter must be of type 'object'");
ParameterInfo argsParameter = invoke.GetParameters()[1];
if (!(typeof(EventArgs).IsAssignableFrom(argsParameter.ParameterType)))
throw new ArgumentException("The second delegate parameter must be derived from type 'EventArgs'");
if (invoke.ReturnType != typeof(void))
throw new ArgumentException("The delegate return type must be void.");
}
public void Add(T eh)
{
if (eh != null)
{
Delegate d = (Delegate)(object)eh;
if (d.Method.DeclaringType.GetCustomAttributes(typeof(CompilerGeneratedAttribute), false).Length != 0)
throw new ArgumentException("Cannot create weak event to anonymous method with closure.");
if (eventEntries.Count == eventEntries.Capacity)
RemoveDeadEntries();
WeakReference target = d.Target != null ? new WeakReference(d.Target) : null;
eventEntries.Add(new EventEntry(d.Method, target));
}
}
void RemoveDeadEntries()
{
eventEntries.RemoveAll(ee => ee.TargetReference != null && !ee.TargetReference.IsAlive);
}
public void Remove(T eh)
{
if (eh != null)
{
Delegate d = (Delegate)(object)eh;
for (int i = eventEntries.Count - 1; i >= 0; i--)
{
EventEntry entry = eventEntries[i];
if (entry.TargetReference != null)
{
object target = entry.TargetReference.Target;
if (target == null)
{
eventEntries.RemoveAt(i);
}
else if (target == d.Target && entry.TargetMethod == d.Method)
{
eventEntries.RemoveAt(i);
break;
}
}
else
{
if (d.Target == null && entry.TargetMethod == d.Method)
{
eventEntries.RemoveAt(i);
break;
}
}
}
}
}
public void Raise(object sender, EventArgs e)
{
int stepExceptionHelp = 0;
try
{
bool needsCleanup = false;
object[] parameters = {sender, e};
foreach (EventEntry ee in eventEntries.ToArray())
{
stepExceptionHelp = 1;
if (ee.TargetReference != null)
{
stepExceptionHelp = 2;
object target = ee.TargetReference.Target;
if (target != null)
{
stepExceptionHelp = 3;
ee.TargetMethod.Invoke(target, parameters);
}
else
{
needsCleanup = true;
}
}
else
{
stepExceptionHelp = 4;
ee.TargetMethod.Invoke(null, parameters);
}
}
if (needsCleanup)
{
stepExceptionHelp = 5;
RemoveDeadEntries();
}
stepExceptionHelp = 6;
}
catch (Exception ex)
{
string appName = Assembly.GetEntryAssembly().GetName().Name;
if (!EventLog.SourceExists(appName))
{
EventLog.CreateEventSource(appName, "Application");
EventLog.WriteEntry(appName,
String.Format("Exception happen in 'SmartWeakEvent.Raise()': {0}. Stack: {1}. Additional int: {2}.", ex.Message, ex.StackTrace, stepExceptionHelp), EventLogEntryType.Error);
}
throw;
}
}
}
}
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Diagnostics;
using System.Linq.Expressions;
using System.Runtime.CompilerServices;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Threading;
using System.Xml.Serialization;
using HQ.Util.General.Log;
using HQ.Util.General.WeakEvent;
using JetBrains.Annotations;
// using System.Windows.Forms;
// using Microsoft.CSharp.RuntimeBinder;
// ATTENTION: Can only be used with Framework 4.0 and up
namespace HQ.Util.General.Notification
{
[Serializable]
public class NotifyPropertyChangedThreadSafeAsyncWeakBase : INotifyPropertyChanged
{
// ******************************************************************
[XmlIgnore]
[field: NonSerialized]
public SmartWeakEvent<PropertyChangedEventHandler> SmartPropertyChanged = new SmartWeakEvent<PropertyChangedEventHandler>();
[XmlIgnore]
[field: NonSerialized]
private Dispatcher _dispatcher = null;
// ******************************************************************
public event PropertyChangedEventHandler PropertyChanged
{
add
{
SmartPropertyChanged.Add(value);
}
remove
{
SmartPropertyChanged.Remove(value);
}
}
// ******************************************************************
[Browsable(false)]
[XmlIgnore]
public Dispatcher Dispatcher
{
get
{
if (_dispatcher == null)
{
_dispatcher = Application.Current?.Dispatcher;
if (_dispatcher == null)
{
if (Application.Current?.MainWindow != null)
{
_dispatcher = Application.Current.MainWindow.Dispatcher;
}
}
}
return _dispatcher;
}
set
{
if (_dispatcher == null && _dispatcher != value)
{
Debug.Print("Dispatcher has changed??? ");
}
_dispatcher = value;
}
}
// ******************************************************************
[NotifyPropertyChangedInvocator]
protected void NotifyPropertyChanged([CallerMemberName] String propertyName = null)
{
try
{
if (Dispatcher == null || Dispatcher.CheckAccess()) // Can be null in case of Console app
{
SmartPropertyChanged.Raise(this, new PropertyChangedEventArgs(propertyName));
}
else
{
Dispatcher.BeginInvoke(
new Action(() => SmartPropertyChanged.Raise(this, new PropertyChangedEventArgs(propertyName))));
}
}
catch (TaskCanceledException ex) // Prevent MT error when closing app...
{
Log.Log.Instance.AddEntry(LogType.LogException, "An exception occured when trying to notify.", ex);
}
}
// ******************************************************************
[NotifyPropertyChangedInvocator]
protected void NotifyPropertyChanged<T2>(Expression<Func<T2>> propAccess)
{
try
{
var asMember = propAccess.Body as MemberExpression;
if (asMember == null)
return;
string propertyName = asMember.Member.Name;
if (Dispatcher == null || Dispatcher.CheckAccess()) // Can be null in case of Console app
{
SmartPropertyChanged.Raise(this, new PropertyChangedEventArgs(propertyName));
}
else
{
Dispatcher.BeginInvoke(new Action(() => SmartPropertyChanged.Raise(this, new PropertyChangedEventArgs(propertyName))));
}
}
catch (TaskCanceledException ex) // Prevent MT error when closing app...
{
Log.Log.Instance.AddEntry(LogType.LogException, "An exception occured when trying to notify.", ex);
}
}
// ******************************************************************
protected bool UpdateField<T>(ref T field, T value, [CallerMemberName] string propertyName = null)
{
if (!EqualityComparer<T>.Default.Equals(field, value))
{
field = value;
NotifyPropertyChanged(propertyName);
return true;
}
return false;
}
// ******************************************************************
}
}
using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Threading;
using HQ.Util.General.Notification;
namespace HQ.Util.General
{
/// <summary>
/// This is the centralized calss to obtain the Dispatcher in order to make sure to get the appropriate one (the MainWindow dispatcher).
/// If you need a specidifc thread dispatcher, please refer to System.Windows.Threading.Dispatcher or Dispatcher.CurrentDispatcher.
/// This dispatcher should be set at the initialization (start) of any GUI executable: ex: Global.Instance.Dispatcher = Application.Current.Dispatcher;
/// </summary>
public class Global : NotifyPropertyChangedThreadSafeAsyncWeakBase
{
public delegate void IsBusyChangeHandler(bool isBusy);
/// <summary>
/// This event happen only the UI thread in low priority
/// </summary>
public event IsBusyChangeHandler IsBusyChange;
private readonly ConcurrentStack<bool> _stackBusy = new ConcurrentStack<bool>();
// ******************************************************************
public static void Init(Dispatcher dispatcher)
{
Instance.Dispatcher = dispatcher;
}
// ******************************************************************
public static Global Instance = new Global();
// ******************************************************************
private Global()
{
_busyLifeTrackerStack = new LifeTrackerStack(() => PushState(), PullState);
}
// ******************************************************************
/// <summary>
/// Will set busy state temporary until object is disposed where
/// the state will be back to its previous state.
/// </summary>
/// <param name="isBusy"></param>
/// <returns></returns>
public LifeTracker GetDisposableBusyState(bool isBusy = true)
{
return new LifeTracker(() => PushState(isBusy), PullState);
}
// ******************************************************************
private bool _isBusy;
/// <summary>
/// This property should be use by the GUI part in order to control the mouse cursor
/// </summary>
public bool IsBusy
{
get => _isBusy;
private set
{
if (value == _isBusy) return;
_isBusy = value;
Dispatcher.BeginInvoke(new Action(() => IsBusyChange?.Invoke(_isBusy)), DispatcherPriority.ContextIdle);
NotifyPropertyChanged();
}
}
private readonly object _objLockBusyStateChange = new object();
// ******************************************************************
/// <summary>
/// Always prefer usage of "Using(Global.Instance.GetDisposableBusyState())" whenever possible.
/// Otherwise ensure to call Pull State to get back previous state of the cursor when action is
/// completed
/// </summary>
/// <param name="isBusy"></param>
public void PushState(bool isBusy = true)
{
lock (_objLockBusyStateChange)
{
_stackBusy.Push(isBusy);
IsBusy = isBusy;
}
}
// ******************************************************************
public void PullState()
{
lock (_objLockBusyStateChange)
{
_stackBusy.TryPop(out bool isBusy);
if (_stackBusy.TryPeek(out isBusy))
{
IsBusy = isBusy;
}
else
{
IsBusy = false;
}
}
}
// ******************************************************************
private readonly LifeTrackerStack _busyLifeTrackerStack = null;
/// <summary>
/// Only kept for historical reason / compatibility with previous code
/// </summary>
[Obsolete("Use direct 'using(Gloabl.Instance.GetDisposableBusyState(isBusy))' which is simpler")]
public LifeTrackerStack BusyLifeTrackerStack
{
get { return _busyLifeTrackerStack; }
}
// ******************************************************************
// private int _latestVersionExecuted = 0;
private int _currentVersionRequired = 0;
private readonly object _objLockRunOnce = new object();
private readonly Dictionary<int, GlobalRunOncePerQueueData> _actionsToRunOncePerQueue =
new Dictionary<int, GlobalRunOncePerQueueData>();
private readonly int _countOfRequestInQueue = 0;
/// <summary>
/// It will record all action once per key and it
/// once per Dispatcher queue roll over (on ContextIdle).
/// When the dispatcher reach the DispatcherPriority.ContextIdle, it will
/// run all action once.
/// Thread safe... no action will be lost but can be run twice or more if
/// some are added by other thread(s) at the same time one is executed.
/// </summary>
/// EO: sorry for the name but it is the best found
/// <param name="key"></param>
/// <param name="action"></param>
public void RunOncePerQueueRollOnDispatcherThread(int key, Action action)
{
lock (_objLockRunOnce)
{
if (!_actionsToRunOncePerQueue.TryGetValue(key, out GlobalRunOncePerQueueData data))
{
data = new GlobalRunOncePerQueueData(action);
_actionsToRunOncePerQueue.Add(key, data);
}
_currentVersionRequired++;
data.VersionRequired = _currentVersionRequired;
}
if (_countOfRequestInQueue <= 1)
{
Dispatcher.CurrentDispatcher.BeginInvoke(DispatcherPriority.ContextIdle, new Action(ExecuteActions));
}
}
// ******************************************************************
private void ExecuteActions()
{
int versionExecute;
List<GlobalRunOncePerQueueData> datas = null;
lock (_objLockRunOnce)
{
versionExecute = _currentVersionRequired;
datas = _actionsToRunOncePerQueue.Values.ToList();
}
foreach (var data in datas)
{
data.Action();
}
lock (_objLockRunOnce)
{
List<int> keysToRemove = new List<int>();
foreach (var kvp in _actionsToRunOncePerQueue)
{
if (kvp.Value.VersionRequired <= versionExecute)
{
keysToRemove.Add(kvp.Key);
}
}
keysToRemove.ForEach(k => _actionsToRunOncePerQueue.Remove(k));
if (_actionsToRunOncePerQueue.Count == 0)
{
// _latestVersionExecuted = 0;
_currentVersionRequired = 0;
}
else
{
// _latestVersionExecuted = versionExecute;
}
}
}
// ******************************************************************
}
}
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Input;
using System.Windows.Threading;
using HQ.Util.General;
using HQ.Util.General.Notification;
using Microsoft.VisualBasic.Devices;
using System.Windows;
using Mouse = System.Windows.Input.Mouse;
using System.Threading;
namespace HQ.Wpf.Util
{
public class AppGlobal
{
// ******************************************************************
public static void Init(Dispatcher dispatcher)
{
if (System.Windows.Input.Keyboard.IsKeyDown(Key.LeftShift) || System.Windows.Input.Keyboard.IsKeyDown(Key.RightShift))
{
var res = MessageBox.Show($"'{AppInfo.AppName}' has been started with shift pressed. Do you want to wait for the debugger (1 minute wait)?", "Confirmation", MessageBoxButton.YesNo,
MessageBoxImage.Exclamation, MessageBoxResult.No);
if (res == MessageBoxResult.Yes)
{
var start = DateTime.Now;
while (!Debugger.IsAttached)
{
if ((DateTime.Now - start).TotalSeconds > 60)
{
break;
}
Thread.Sleep(100);
}
}
}
if (dispatcher == null)
{
throw new ArgumentNullException();
}
Global.Init(dispatcher);
Instance.Init();
}
// ******************************************************************
public static readonly AppGlobal Instance = new AppGlobal();
// ******************************************************************
private AppGlobal()
{
}
// ******************************************************************
private void Init()
{
Global.Instance.PropertyChanged += AppGlobalPropertyChanged;
}
// ******************************************************************
void AppGlobalPropertyChanged(object sender, System.ComponentModel.PropertyChangedEventArgs e)
{
if (e.PropertyName == "IsBusy")
{
if (Global.Instance.IsBusy)
{
if (Global.Instance.Dispatcher.CheckAccess())
{
Mouse.OverrideCursor = Cursors.Wait;
}
else
{
Global.Instance.Dispatcher.BeginInvoke(new Action(() => Mouse.OverrideCursor = Cursors.Wait));
}
}
else
{
if (Global.Instance.Dispatcher.CheckAccess())
{
Mouse.OverrideCursor = Cursors.Arrow;
}
else
{
Global.Instance.Dispatcher.BeginInvoke(new Action(() => Mouse.OverrideCursor = Cursors.Arrow));
}
}
}
}
// ******************************************************************
}
}
using HQ.Util.General;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Input;
namespace HQ.Wpf.Util
{
/// <summary>
/// Ensure window cursor is "normal" (arrow) when visible.
/// Usage: In Window class, define a member: OverrideCursorMtForWindow. Instantiate in constructor after Initialisation.
/// </summary>
public class WindowWithAutoBusyState
{
// ******************************************************************
Window _window;
bool _nextStateShoulBeVisible = true;
// ******************************************************************
public WindowWithAutoBusyState()
{
}
// ******************************************************************
public void Init(Window window)
{
_window = window;
_window.Cursor = Cursors.Wait;
_window.Loaded += (object sender, RoutedEventArgs e) => _window.Cursor = Cursors.Arrow;
_window.IsVisibleChanged += WindowIsVisibleChanged;
_window.Closed += WindowClosed;
}
// ******************************************************************
private void WindowIsVisibleChanged(object sender, DependencyPropertyChangedEventArgs e)
{
if (_window.IsVisible)
{
if (_nextStateShoulBeVisible)
{
Global.Instance.PushState(false);
_nextStateShoulBeVisible = false;
}
}
else
{
if (!_nextStateShoulBeVisible)
{
Global.Instance.PullState();
_nextStateShoulBeVisible = true;
}
}
}
// ******************************************************************
private void WindowClosed(object sender, EventArgs e)
{
if (!_nextStateShoulBeVisible)
{
Global.Instance.PullState();
_nextStateShoulBeVisible = true;
}
}
// ******************************************************************
}
}