C# 如何正确实现WPF扩展工具包中的忙指示器

好的，我已经为这个问题挣扎了相当长的一段时间，并且已经阅读了一篇又一篇文章，试图对这个问题有一个想法。我正在尝试实施繁忙指标，但只取得了部分成功。我有一个Shell视图，我用BusyIndicator包装了它，如下所示：

<Window x:Class="Foundation.Shell"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:controls="clr-namespace:Library.Controls.Views;assembly=Library"
    xmlns:l="clr-namespace:Library.StaticClasses"
    xmlns:xctk="http://schemas.xceed.com/wpf/xaml/toolkit"
    Name="ShellView"
    Style="{StaticResource BusyWindowStyle}"
    SourceInitialized="Window_SourceInitialized"
    DataContext="{StaticResource ShellVM}">

    <xctk:BusyIndicator x:Name="ShellBusyIndicator" IsBusy="{Binding IsBusy}"  DisplayAfter="0">
        <Grid>
            <!--Content Here -->
        </Grid>
    </xctk:BusyIndicator>

接下来，我将使用一个名为StateManager的静态类，我可以从任何地方调用该类来触发繁忙指示器：

public static class StateManager
{
    public static String IsBusyMessage { get; set; }

    public static void IsBusyProcess(Action action)
    {
        IsBusyProcess(action, "Processing...");
    }

    public static void IsBusyProcess(Action action, String isBusyMessage)
    {
        IsBusyMessage = isBusyMessage;
        IsBusy = true;
        Application.Current.Dispatcher.Invoke(action, System.Windows.Threading.DispatcherPriority.Background);
        IsBusy = false;
    }

    private static bool _IsBusy;
    public static bool IsBusy
    {
        get
        {
            return _IsBusy;
        }
        set
        {
            if (_IsBusy != value)
            {
                _IsBusy = value;

                IsBusyChange(null, null);
            }
        }
    }

    public delegate void IsBusyHandler(object sender, EventArgs e);

    public static event IsBusyHandler IsBusyChange;
}

最后，我在代码中触发忙碌指示器，如下所示：

StateManager.IsBusyProcess(() =>
        {
            this.Validate();

            if (!HasValidationErrors)
            {
                if (this.CustomerControlVM.SaveCustomer() != 0)
                {
                    VehicleControlVM.VehicleModel.CustomerID = this.CustomerControlVM.CustomerModel.CustomerID;
                    this.VehicleControlVM.SaveVehicle();

                    ComplaintsView complaintsControl = new ComplaintsView();

                    (complaintsControl.DataContext as ComplaintsViewModel).CurrentVehicle = this.VehicleControlVM.VehicleModel;
                    (complaintsControl.DataContext as ComplaintsViewModel).CurrentCustomer = this.CustomerControlVM.CustomerModel;
                    StateManager.LoadView(complaintsControl, PageTransitionType.SlideLeft);
                }
            }

            StateManager.IsBusy = false;
        });

---

总之，可以从应用程序中的任何位置调用StateManager。更改StateManager.IsBusy属性时，将触发在ShellViewModel中订阅的事件。发生这种情况时，ShellViewModel中的IsBusy属性被设置为true，这可能会导致IsBusy指示器显示。逻辑工作正常，因为ShellViewModel中的IsBusy正在设置中，busy指示器按预期显示。工作不正常的是“忙碌”指示器没有设置动画。它只是停滞不前。我觉得这是一个线程问题，但要么我对UI线程的理解有偏差，要么我没有看到一些对您来说很明显的东西。我意识到IsBusy逻辑不能与UI在同一个线程上，但我认为，由于我的逻辑发生在视图模型中，所以这不应该是一个问题。我错了吗？有什么想法吗？另一件可能有用的事情是：我甚至在显示指示器时遇到了麻烦，于是创建了这篇文章，这篇文章得到了解决：

好了，我终于实现了忙碌指示器。这是一项相当艰巨的任务，但我从中学到了一些东西。至少我有东西要展示。虽然我没有弄清楚为什么我的代码在发布时无法工作，但我确实发现我试图在操作中执行与UI相关的代码，这肯定是一个问题。我不是100%确定，因为我做了一点重新编写，我没有足够的青蛙恢复我的代码来玩它。但是，问题得到了回答，下面是我如何实现繁忙指标的：

public static class StateManager
{
    public static String IsBusyMessage { get; set; }

    public static void IsBusyProcess(Action action)
    {
        IsBusyProcess(action, "Processing...");
    }

    public static void IsBusyProcess(Action action, String isBusyMessage)
    {
        IsBusyMessage = isBusyMessage;
        IsBusy = true;
        Application.Current.Dispatcher.Invoke(action, System.Windows.Threading.DispatcherPriority.Background);
        IsBusy = false;
    }

    private static bool _IsBusy;
    public static bool IsBusy
    {
        get
        {
            return _IsBusy;
        }
        set
        {
            if (_IsBusy != value)
            {
                _IsBusy = value;

                IsBusyChange(null, null);
            }
        }
    }

    public delegate void IsBusyHandler(object sender, EventArgs e);

    public static event IsBusyHandler IsBusyChange;
}

首先，除了IsBusy的属性集和绑定之外，我的视图中没有任何更改。最后，我将事件订阅从视图模型移动到视图的代码隐藏中。我的视图的代码如下所示：

public partial class Shell : Window
{
    #region Constructor(s)

    public Shell()
    {
        InitializeComponent();
        StateManager.IsBusyChange += new StateManager.IsBusyHandler(InitiateIsBusy);
    }

    #endregion Constructor(s)

    #region Event Actions

    public void InitiateIsBusy(object sender, BusyActionEventArgs e)
    {
        BackgroundWorker worker = new BackgroundWorker();

        worker.DoWork += (o, ea) =>
        {
            e.IsBusyAction.Invoke();
            //Dispatcher.Invoke((Action)(() => e.IsBusyAction()));
        };
        worker.RunWorkerCompleted += (o, ea) =>
        {
            this.ShellBusyIndicator.IsBusy = false;
        };

        this.ShellBusyIndicator.BusyContent = e.BusyMessage;
        this.ShellBusyIndicator.IsBusy = true;

        worker.RunWorkerAsync();
    }

    #endregion Event Actions
}

public static class StateManager
{
    public static void IsBusyProcess(Action action)
    {
        IsBusyProcess(action, "Processing...");
    }

    public static void IsBusyProcess(Action action, String isBusyMessage)
    {
        BusyActionEventArgs args = new BusyActionEventArgs()
        {
            IsBusyAction = action,
            BusyMessage = isBusyMessage
        };

        IsBusyChange(null, args);
    }

    public delegate void IsBusyHandler(object sender, BusyActionEventArgs e);

    public static event IsBusyHandler IsBusyChange;
}

StateManager.IsBusyProcess(() =>
        {
            this.Validate();

            if (!HasValidationErrors)
            {
                if (this.CustomerControlVM.SaveCustomer() != 0)
                {
                    VehicleControlVM.VehicleModel.CustomerID = this.CustomerControlVM.CustomerModel.CustomerID;
                    this.VehicleControlVM.SaveVehicle();
                }
            }
        });

        ComplaintsView complaintsControl = new ComplaintsView();

        (complaintsControl.DataContext as ComplaintsViewModel).CurrentVehicle = this.VehicleControlVM.VehicleModel;
        (complaintsControl.DataContext as ComplaintsViewModel).CurrentCustomer = this.CustomerControlVM.CustomerModel;
        StateManager.LoadView(complaintsControl, PageTransitionType.SlideLeft);

首先，请注意，我创建了扩展EventArgs的BusyActionEventArgs类。它放在我的库项目中，该项目依赖于我的解决方案中的每个项目：

public class BusyActionEventArgs : EventArgs
{
    public Action IsBusyAction { get; set; }
    public string BusyMessage { get; set; }
}

最后，我的StateManager现在如下所示：

public partial class Shell : Window
{
    #region Constructor(s)

    public Shell()
    {
        InitializeComponent();
        StateManager.IsBusyChange += new StateManager.IsBusyHandler(InitiateIsBusy);
    }

    #endregion Constructor(s)

    #region Event Actions

    public void InitiateIsBusy(object sender, BusyActionEventArgs e)
    {
        BackgroundWorker worker = new BackgroundWorker();

        worker.DoWork += (o, ea) =>
        {
            e.IsBusyAction.Invoke();
            //Dispatcher.Invoke((Action)(() => e.IsBusyAction()));
        };
        worker.RunWorkerCompleted += (o, ea) =>
        {
            this.ShellBusyIndicator.IsBusy = false;
        };

        this.ShellBusyIndicator.BusyContent = e.BusyMessage;
        this.ShellBusyIndicator.IsBusy = true;

        worker.RunWorkerAsync();
    }

    #endregion Event Actions
}

public static class StateManager
{
    public static void IsBusyProcess(Action action)
    {
        IsBusyProcess(action, "Processing...");
    }

    public static void IsBusyProcess(Action action, String isBusyMessage)
    {
        BusyActionEventArgs args = new BusyActionEventArgs()
        {
            IsBusyAction = action,
            BusyMessage = isBusyMessage
        };

        IsBusyChange(null, args);
    }

    public delegate void IsBusyHandler(object sender, BusyActionEventArgs e);

    public static event IsBusyHandler IsBusyChange;
}

StateManager.IsBusyProcess(() =>
        {
            this.Validate();

            if (!HasValidationErrors)
            {
                if (this.CustomerControlVM.SaveCustomer() != 0)
                {
                    VehicleControlVM.VehicleModel.CustomerID = this.CustomerControlVM.CustomerModel.CustomerID;
                    this.VehicleControlVM.SaveVehicle();
                }
            }
        });

        ComplaintsView complaintsControl = new ComplaintsView();

        (complaintsControl.DataContext as ComplaintsViewModel).CurrentVehicle = this.VehicleControlVM.VehicleModel;
        (complaintsControl.DataContext as ComplaintsViewModel).CurrentCustomer = this.CustomerControlVM.CustomerModel;
        StateManager.LoadView(complaintsControl, PageTransitionType.SlideLeft);

注意，我为IsBusyProcess方法创建了一个重载，因此如果愿意，我可以发送一条自定义的忙消息

现在，如果我修改问题代码段中的代码，我实际使用的是忙碌指示器，它如下所示：

public partial class Shell : Window
{
    #region Constructor(s)

    public Shell()
    {
        InitializeComponent();
        StateManager.IsBusyChange += new StateManager.IsBusyHandler(InitiateIsBusy);
    }

    #endregion Constructor(s)

    #region Event Actions

    public void InitiateIsBusy(object sender, BusyActionEventArgs e)
    {
        BackgroundWorker worker = new BackgroundWorker();

        worker.DoWork += (o, ea) =>
        {
            e.IsBusyAction.Invoke();
            //Dispatcher.Invoke((Action)(() => e.IsBusyAction()));
        };
        worker.RunWorkerCompleted += (o, ea) =>
        {
            this.ShellBusyIndicator.IsBusy = false;
        };

        this.ShellBusyIndicator.BusyContent = e.BusyMessage;
        this.ShellBusyIndicator.IsBusy = true;

        worker.RunWorkerAsync();
    }

    #endregion Event Actions
}

public static class StateManager
{
    public static void IsBusyProcess(Action action)
    {
        IsBusyProcess(action, "Processing...");
    }

    public static void IsBusyProcess(Action action, String isBusyMessage)
    {
        BusyActionEventArgs args = new BusyActionEventArgs()
        {
            IsBusyAction = action,
            BusyMessage = isBusyMessage
        };

        IsBusyChange(null, args);
    }

    public delegate void IsBusyHandler(object sender, BusyActionEventArgs e);

    public static event IsBusyHandler IsBusyChange;
}

StateManager.IsBusyProcess(() =>
        {
            this.Validate();

            if (!HasValidationErrors)
            {
                if (this.CustomerControlVM.SaveCustomer() != 0)
                {
                    VehicleControlVM.VehicleModel.CustomerID = this.CustomerControlVM.CustomerModel.CustomerID;
                    this.VehicleControlVM.SaveVehicle();
                }
            }
        });

        ComplaintsView complaintsControl = new ComplaintsView();

        (complaintsControl.DataContext as ComplaintsViewModel).CurrentVehicle = this.VehicleControlVM.VehicleModel;
        (complaintsControl.DataContext as ComplaintsViewModel).CurrentCustomer = this.CustomerControlVM.CustomerModel;
        StateManager.LoadView(complaintsControl, PageTransitionType.SlideLeft);

注意我从操作范围中删除的代码。此代码是UI代码，如果在范围内，则会导致错误

---

我希望这能帮助其他想要实现类似功能或遇到麻烦的人。感谢stackoverflow刚刚出现在这个页面上。有时说出来（或打字）会有所不同。

因此，正在运行的另一个进程需要一个忙碌的指示器，它也在一个单独的线程上吗？嗨，Felix。谢谢你的回复。长时间运行的进程应该与ShellViewModel在同一个线程上，除非我忽略了什么。我试图使用Threads窗口（我以前从未使用过），但它似乎表明我的ShellView和ShellViewModel都在主线程中。我不确定这是怎么可能的，所以我不相信它，我更不相信我自己的观点