Question

我有我的xaml：

        <Window x:Class="Views.ShellView"
                xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
                xmlns:xctk="http://schemas.xceed.com/wpf/xaml/toolkit"
                xmlns:i="http://schemas.microsoft.com/expression/2010/interactivity"
                Height="768" Width="1024" WindowStartupLocation="CenterScreen"
                Title="{Binding Path=DisplayName}">

            <xctk:BusyIndicator x:Name="BusyIndicator"  IsBusy="{Binding IsBusy, UpdateSourceTrigger=PropertyChanged}" >

                <TreeView Style="{StaticResource TableSchemaTreeViewStyle}" ItemContainerStyle="{StaticResource SchemaTreeViewStyle}" Margin="0,15,0,0" 
                                  x:Name="TreeViewSchema" 
                                  TreeViewItem.Expanded="TreeViewSchema_OnExpanded" 
                                  TreeViewItem.Selected="TreeViewSchema_OnSelected" 
                                  Grid.Row="2" 
                                  ItemsSource="{Binding CurrentProject.Tables, Converter={StaticResource TreeViewSortingConverter}, ConverterParameter=FullTableName}">
                </TreeView>

            </xctk:BusyIndicator>
        </Window>

假设我在代码隐藏中运行的任务很长，它在UI线程上执行（对treeview进行长时间过滤，它可以有超过1000个表，每个表中有超过100列）。

让我说我迭代并为每个项目设置tableTreeViewItem.Visibility = Visibility.Collapsed;。

我想要的：通过在此操作之前将其设置为true来显示BusyIndicator：

BusyIndicator.IsBusy = true;。

问题：UI线程和绑定上的两个操作都无法按预期工作。我尝试了几件事：

BusyIndicator.IsBusy = true;

TaskScheduler uiScheduler = TaskScheduler.FromCurrentSynchronizationContext();

Task.Factory.StartNew(() =>
{

    tableTreeViewItem.Visibility = Visibility.Collapsed;

}, CancellationToken.None, TaskCreationOptions.None, uiScheduler).ContinueWith(task => Dispatcher.Invoke(() =>
{
    BusyIndicator.IsBusy = false;
}));

使用调度员：

BusyIndicator.IsBusy = true;

//long-running UI task
tableTreeViewItem.Visibility = Visibility.Collapsed;

BusyIndicator.IsBusy = false;

但它不起作用，任何想法如何解决它？

PSS

我做了一些更新，我决定抓取所有数据并存储哪个树视图项应该可见或隐藏。

所以我有用于存储过滤方法

的表，可见性和可见列的类

 class TreeViewItemVisibilityTableContainer
{
    private TreeViewItem _treeViewItem;
    private TableModel _table;
    private Visibility _visibility;
    private List<ColumnModel> _visibleColumns;

    public TableModel Table
    {
        get { return _table; }
        set { _table = value; }
    }
    public TreeViewItem TreeViewItem
    {
        get { return _treeViewItem; }
        set { _treeViewItem = value; }
    }
    public Visibility Visibility
    {
        get { return _visibility; }
        set { _visibility = value; }
    }
    public List<ColumnModel> VisibleColumns
    {
        get { return _visibleColumns; }
        set { _visibleColumns = value; }
    }
}

现在我可以直接在UI线程上过滤所有这些工作人员：

 System.Action filterTreeViewItemsVisibility = () => Dispatcher.Invoke(() =>
            {
                foreach (var item in itemsToFilter)
                {
                    item.TreeViewItem.Visibility = item.Visibility;
                    var capturedItemForClosure = item;

                    if (item.Visibility == Visibility.Visible)
                    {
                        if (item.VisibleColumns.Any())
                        {
                            item.TreeViewItem.Items.Filter = item.TreeViewItem.Items.Filter =
                                treeViewItem =>
                                    capturedItemForClosure.VisibleColumns.Any(
                                        columnModel => columnModel.Equals(treeViewItem));
                        }
                        else
                        {
                            item.TreeViewItem.Visibility = Visibility.Collapsed;
                        }
                    }
                }
            });

            IoC.Get<IBusyIndicatorHelper>().PerformLongrunningAction(filterTreeViewItemsVisibility, IoC.Get<IShellViewModel>());

但它仍然超级慢

Answer 1

这是忙碌指标的解决方案。

显示解决方案的组件很少

BusyIndicator 用户控制
的 AbortableBackgroundWorker

MainWindow 作为应用程序窗口

BusyIndicator 用户控件

BusyIndicator.xaml - 非常简单

<UserControl x:Class="BusyIndicatorExample.BusyInidicator" 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" mc:Ignorable="d" d:DesignHeight="300" d:DesignWidth="300" Visibility="Collapsed"> <Grid Background="#BFFFFFFF" > <TextBlock Text="Loading data..." HorizontalAlignment="Center" VerticalAlignment="Center" Foreground="#FF2C2C2C" FontSize="16" FontWeight="Bold" /> </Grid> </UserControl>

<强> BusyIndicator.xaml.cs

using System; using System.Windows.Controls; namespace BusyIndicatorExample { /// <summary> /// Interaction logic for BusyInidcator.xaml /// </summary> public partial class BusyInidicator : UserControl { public BusyInidicator() { InitializeComponent(); }

显示指标的方法

public void Start() { this.Dispatcher.Invoke(new Action(delegate() { this.Visibility = System.Windows.Visibility.Visible; }), System.Windows.Threading.DispatcherPriority.Normal); }

隐藏指标的方法

public void Stop() { this.Dispatcher.Invoke(new Action(delegate() { this.Visibility = System.Windows.Visibility.Collapsed; }), System.Windows.Threading.DispatcherPriority.Normal); } } }
用于模拟非UI任务的
AbortableBackgroundWorker

using System; using System.ComponentModel; using System.Threading; namespace BusyIndicatorExample { /// <summary> /// Abortable background worker /// </summary> public class AbortableBackgroundWorker : BackgroundWorker { //Internal Thread private Thread workerThread; protected override void OnDoWork(DoWorkEventArgs e) { try { base.OnDoWork(e); } catch (ThreadAbortException) { e.Cancel = true; //We must set Cancel property to true! Thread.ResetAbort(); //Prevents ThreadAbortException propagation } } public void Abort() { if (workerThread != null) { workerThread.Abort(); workerThread = null; } } } }

最后，模拟过程的 MainWindow

<强> MainWindow.xaml

<Window x:Class="BusyIndicatorExample.MainWindow" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:local="clr-namespace:BusyIndicatorExample" Title="MainWindow" Height="350" Width="525"> <Grid> <Button Content="Start Data Loading" HorizontalAlignment="Left" Margin="63,42,0,0" VerticalAlignment="Top" Width="125" Height="28" Click="Button_Click"/> <TextBox HorizontalAlignment="Left" Height="23" Margin="63,87,0,0" TextWrapping="Wrap" Text="{Binding DataString}" VerticalAlignment="Top" Width="412"/> <local:BusyInidicator x:Name="busyIndicator" HorizontalAlignment="Left" Height="100" Margin="177,140,0,0" VerticalAlignment="Top" Width="300"/> </Grid> </Window>

MainWindow.xaml.cs - 这是应用程序代码

using System.ComponentModel; using System.Windows; namespace BusyIndicatorExample { /// <summary> /// Interaction logic for MainWindow.xaml /// </summary> public partial class MainWindow : Window, INotifyPropertyChanged { private AbortableBackgroundWorker _worker;

绑定到文本框的构造函数和公共属性

public MainWindow() { InitializeComponent(); this.DataContext = this; } private string _dataString = "No Data"; public string DataString { get { return _dataString; } set { if (_dataString != value) { _dataString = value; if (PropertyChanged != null) PropertyChanged.Invoke(this, new PropertyChangedEventArgs("DataString")); } } }

按钮点击事件 - 初始化BackgroundWorker并启动它

private void Button_Click(object sender, RoutedEventArgs e) { if(_worker == null) { _worker = new AbortableBackgroundWorker(); _worker.WorkerReportsProgress = true; _worker.WorkerSupportsCancellation = true; _worker.DoWork += _worker_DoWork; _worker.RunWorkerCompleted += _worker_RunWorkerCompleted; } if (!_worker.IsBusy) _worker.RunWorkerAsync(); }

BackgroundWorker事件处理程序

RunWorkerCompleted更新数据字符串并隐藏指标。

void _worker_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e) { DataString = "Data has been loaded"; busyIndicator.Stop(); }

DoWork显示指示符并进入睡眠线程5秒。

void _worker_DoWork(object sender, DoWorkEventArgs e) { DataString = "No Data"; busyIndicator.Start(); System.Threading.Thread.Sleep(5000); } public event PropertyChangedEventHandler PropertyChanged; } }

希望这会有所帮助。根据需要修改代码以适应您的方案可以下载完整的示例项目代码here

如果长时间运行的操作在ui线程上，则显示忙碌指示

1 个答案: