详解WPF如何在基础控件上显示Loading等待动画

<UserControl x:Class="WPFDevelopers.Samples.ExampleViews.BasicControlsExample"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
             xmlns:local="clr-namespace:WPFDevelopers.Samples.ExampleViews"
             xmlns:wpfdev="https://github.com/WPFDevelopersOrg/WPFDevelopers"
             xmlns:controls="clr-namespace:WPFDevelopers.Samples.Controls"
             mc:Ignorable="d"  Background="{DynamicResource BackgroundSolidColorBrush}"
             d:DesignHeight="450" d:DesignWidth="800" Name="MyBasicControls">
<TextBlock Text="Loading" FontSize="20" Margin="0,20,0,0"/>
                    <WrapPanel Margin="0,10">
                        <Button Content="Loading" Click="Loading_Click" 
                            Style="{DynamicResource PrimaryButton}"/>
                        <Button Name="btnLoadingTask" Content="LoadingTask" Click="LoadingTask_Click" 
                                Style="{DynamicResource SuccessPrimaryButton}" Margin="10,0"/>
                        <Button Name="btnLoading" Click="BtnLoading_Click" Content="AddLoading"
                                wpfdev:Loading.Child="{x:Static wpfdev:NormalLoading.Default}"
                                Style="{DynamicResource WarningPrimaryButton}"/>
                        <Button Name="btnOffTask" Click="BtnOffTask_Click" 
                                Margin="10,0" Content="Off Task"
                                Style="{DynamicResource DangerPrimaryButton}"/>
                    </WrapPanel>
  </UserControl>

  private void Loading_Click(object sender, RoutedEventArgs e)
      {
          var task = new Task(() => { Thread.Sleep(5000); });
          task.ContinueWith(previousTask => 
          {
              Loading.SetIsShow(MyBasicControls, false);
          }, 
          TaskScheduler.FromCurrentSynchronizationContext());
          Loading.SetIsShow(MyBasicControls, true);
          task.Start();
      }

private void BtnLoading_Click(object sender, RoutedEventArgs e)
        {
            var task = new Task(() => { Thread.Sleep(5000); });
            task.ContinueWith(previousTask => { Loading.SetIsShow(btnLoading, false); }, TaskScheduler.FromCurrentSynchronizationContext());
            Loading.SetIsShow(btnLoading, true);
            task.Start();
        }

 private void BtnOffTask_Click(object sender, RoutedEventArgs e)
        {
            if (tokenSource == null) return;
            tokenSource.Cancel();
            Loading.SetIsShow(btnLoadingTask, false);
        }
        private CancellationTokenSource tokenSource;

        private void LoadingTask_Click(object sender, RoutedEventArgs e)
        {
            tokenSource = new CancellationTokenSource();
            var cancellationToken = tokenSource.Token;

            var task = new Task(() =>
            {
                for (int i = 0; i < 10; i++)
                {
                    //这里做自己的事情
                    if (tokenSource.IsCancellationRequested)
                        return;
                    Thread.Sleep(1000);
                }
            }, cancellationToken);
            task.ContinueWith(previousTask =>
            {
                if (tokenSource.IsCancellationRequested)
                    return;
                Loading.SetIsShow(btnLoadingTask, false);
            }, TaskScheduler.FromCurrentSynchronizationContext());
            Loading.SetIsShow(btnLoadingTask, true);
            task.Start();
        }