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Tag: VisibleRange Binding MVVM

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0 votes
6k views

Hello.
Thanks for previous answer but I can’t check how it work because of new problem. I develop WPF application and try to use MVVM as architecture pattern. In the Model part of my application I used a loop started in the new thread. In that loop I get some data which received to ViewModel and used as chart data. Looks as usual.
But then I tried to set visible range updated object which bound to axis I get exception ‘System.InvalidOperationException: ‘The calling thread cannot access this object because a different thread owns it.’ in my loop. I know it happens in WPF applications and need to use Dispatcher to solve it. But as I know if you try to use MVVM you not needed to use Dispatcher often because WPF-binding in most cases is thread-safe. That happend in my case? How to solve it?
Parts of my code:

XAML

<Window x:Class="HMI.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:s="http://schemas.abtsoftware.co.uk/scichart"
        xmlns:localVM="clr-namespace:MyCom.HMI.ViewModel"
        mc:Ignorable="d"
        Title="MainWindow" Height="450" Width="800">
    <Window.DataContext>
        <localVM:HMIViewModel/>
    </Window.DataContext>
    <Window.Resources>
        <localVM:InverseBooleanConverter x:Key="InverseBooleanConverter"/>
        <localVM:ProcessStateToColorConverter x:Key="ProcessStateToColorConverter"/>
        <localVM:ProcessStateToStartedConverter x:Key="ProcessStateToStartedConverter"/>
        <localVM:ProcessStateToStoppedConverter x:Key="ProcessStateToStoppedConverter"/>
    </Window.Resources>
    <DockPanel>
        <StackPanel DockPanel.Dock="Top" Orientation="Horizontal">
            <StackPanel DockPanel.Dock="Left" Orientation="Vertical" Width="520">
                <Border DockPanel.Dock="Top" Margin="5" Padding="5" BorderBrush="Black" BorderThickness="1,1,1,1" CornerRadius="5">
                    <StackPanel DockPanel.Dock="left" Orientation="Horizontal" Height="40">
                        <Ellipse Margin="5" Height="20" Width="20" HorizontalAlignment="Left" VerticalAlignment="Center" Stroke="Black" Fill="{Binding ProcessState, Converter={StaticResource ProcessStateToColorConverter}}"/>
                        <Label Content="State" Margin="5" Width="90" HorizontalContentAlignment="Left" VerticalContentAlignment="Center"/>
                    </StackPanel>
                </Border>
                <Border DockPanel.Dock="Top" Margin="5" Padding="5" BorderBrush="Black" BorderThickness="1,1,1,1" CornerRadius="5">
                    <Grid DockPanel.Dock="Left" Height="300">
                        <s:SciChartSurface ChartTitle="Profil" RenderableSeries="{s:SeriesBinding RenderableSeries}">
                            <s:SciChartSurface.XAxis>
                                <s:NumericAxis AxisTitle="Position, m" VisibleRange="{Binding XVisibleRange, Mode=TwoWay}"/>
                            </s:SciChartSurface.XAxis>
                            <s:SciChartSurface.YAxis>
                                <s:NumericAxis AxisTitle="Size, um" VisibleRange="{Binding YVisibleRange, Mode=TwoWay}"/>
                            </s:SciChartSurface.YAxis>
                        </s:SciChartSurface>
                    </Grid>
                </Border>
            </StackPanel>
...

ViewModel

namespace MyCom.HMI.ViewModel
{
    public class HMIViewModel : BindableBase
    {      
        private readonly HMIModel _model = new();

        public HMIViewModel()
        {
            _renderableSeries = new ObservableCollection<IRenderableSeriesViewModel>();

            ((INotifyCollectionChanged)_model.TestControlData).CollectionChanged += (s, e) =>  { TestControlDataChanged(e); };

            InitCharts();
        }

...

        private ObservableCollection<IRenderableSeriesViewModel> _renderableSeries;
        public ObservableCollection<IRenderableSeriesViewModel> RenderableSeries
        {
            get { return _renderableSeries; }
            set
            {
                SetProperty(ref _renderableSeries, value, nameof(RenderableSeries));
            }
        }

        private IRange _xVisibleRange;
        public IRange XVisibleRange
        {
            get => _xVisibleRange;
            set
            {
                if (_xVisibleRange != value)
                {
                    SetProperty(ref _xVisibleRange, value, nameof(XVisibleRange));
                }
            }
        }

        private IRange _yVisibleRange;
        public IRange YVisibleRange
        {
            get => _yVisibleRange;
            set
            {
                if (_yVisibleRange != value)
                {
                    SetProperty(ref _yVisibleRange, value, nameof(YVisibleRange));
                }
            }
        }

        private XyDataSeries<double, double> _lineDataDiameter1;

...

        private void InitCharts()
        { // TODO
            _lineDataDiameter1 = new XyDataSeries<double, double>()
            { 
                SeriesName = "Diameter1"
            };

            RenderableSeries.Add(new LineRenderableSeriesViewModel()
            {
                StrokeThickness = 2,
                Stroke = Colors.SteelBlue,
                DataSeries = _lineDataDiameter1,
                StyleKey = "LineSeriesStyle"
            });
        }

        private void TestControlDataChanged(NotifyCollectionChangedEventArgs args)
        {
            if (args.Action == NotifyCollectionChangedAction.Add && args.NewItems?.Count > 0)
            {
                var testControlActualState = args.NewItems.Cast<TestControlActualState>();

                List<double> xValues = new();
                List<double> yValuesDiameter1 = new();

                foreach (var item in testControlActualState) 
                {
                    if (item.Diameter1 > 0f)
                    {
                        xValues.Add(item.FiberLength);
                        yValuesDiameter1.Add(item.Diameter1);
                    }
                }

                _lineDataDiameter1.Append(xValues, yValuesDiameter1);

                // TODO
                if (xValues.Count > 0)
                {
                    var cuurMaxValueX = xValues.Max();
                    XVisibleRange.Max = cuurMaxValueX;
                    XVisibleRange.Min = cuurMaxValueX - 7000f > 0 ? cuurMaxValueX - 7000f : 0;
                }

                // TODO
                if (yValuesDiameter1.Count > 0)
                {
                    var cuurMaxValueY = yValuesDiameter1.Max();
                    YVisibleRange.Max = cuurMaxValueY + 50;
                    YVisibleRange.Min = 0;
                }
            }
        }

Model

namespace MyCom.HMI.Model
{
    public class HMIModel : BindableBase, IDisposable
    {
        private readonly ObservableCollection<TestControlActualState> _testControlData;
        internal ReadOnlyObservableCollection<TestControlActualState> TestControlData { get; }

        public HMIModel()
        {
            _testControlData = new ObservableCollection<TestControlActualState>();
            TestControlData = new ReadOnlyObservableCollection<TestControlActualState>(_testControlData);
        }

...

        private void StartPollerThread()
        {
            _pollerCancellationToken ??= new CancellationTokenSource();

            if (!_pollerCancellationToken.IsCancellationRequested)
            {
                Task.Factory.StartNew(() => PollerDoWork(_pollerCancellationToken.Token), TaskCreationOptions.LongRunning);
            }
        }

        private void PollerDoWork(CancellationToken cancellationToken)
        {
            try
            {
                Thread.CurrentThread.Priority = ThreadPriority.Lowest;
                IsPollerStarted = true;

                while (!cancellationToken.IsCancellationRequested && (_isKeepConnection || _countOfTrying <= MAX_COUNT_OF_TRYING))
                {
                    try
                    {
                        _testControlData.Add(_emulator.GetTestControlActualState());

                        if (!_isKeepConnection && _countOfTrying > 0)
                        {
                            Thread.Sleep(_pollerTimeout / REASK_COEFICIENT);
                            continue;
                        }
                    }
                    catch
                    {
                        // Thread must be alive!!! ...ALWAYS!!!
                    }
                    Thread.Sleep(_pollerTimeout);
                }
            }
            finally
            {
                IsPollerStarted = false;
                _pollerCancellationToken = null;
            }
        }
0 votes
5k views

When I try to bind VisibleRange as a simple binding on the XAxis it works perfectly.

                <scichart:SciChartSurface.XAxis>
                    <scichart:NumericAxis AxisTitle="Tempo (s)" 
                                          VisibleRange="{Binding XVisibleRange, Mode=TwoWay}"/>
                </scichart:SciChartSurface.XAxis>

But, in my case I have only one chart beeing displayed but two “RenderableSeries” in which only one of them is displayed, accordingly to the user selection. I use triggers for this and it works like a charm.

                <scichart:SciChartSurface.Resources>

                    <Style TargetType="{x:Type scichart:SciChartSurface}">
                        <Style.Triggers>
                            <DataTrigger Binding="{Binding ElementName=DAQ1_Selected, Path=IsChecked}" Value="true">
                                <Setter Property="RenderableSeries" Value="{scichart:SeriesBinding RenderableSeriesViewModels[0]}"/>
                            </DataTrigger>
                            <DataTrigger Binding="{Binding ElementName=DAQ1_Selected, Path=IsChecked}" Value="false">
                                <Setter Property="RenderableSeries" Value="{scichart:SeriesBinding RenderableSeriesViewModels[1]}"/>
                            </DataTrigger>
                        </Style.Triggers>
                    </Style>

                </scichart:SciChartSurface.Resources>

Now I’m trying to set the “VisibleRange” of each “RenderableSeries” with triggers but I cannot achieve that because there is no option to binding on the setter.

<scichart:SciChartSurface.XAxis>
                            <scichart:NumericAxis AxisTitle="Tempo (s)" 
                                              GrowBy="0.01,0.01">

                                <Style TargetType="{x:Type scichart:NumericAxis}">
                                    <Style.Triggers>
                                        <DataTrigger Binding="{Binding ElementName=DAQ1_Selected, Path=IsChecked}" Value="true">
                                            <Setter Property="VisibleRange" Value="{scichart:AxesBinding XVisibleRange[0], Mode=TwoWay}" />
                                        </DataTrigger>
                                        <DataTrigger Binding="{Binding ElementName=DAQ1_Selected, Path=IsChecked}" Value="false">
                                            <Setter Property="VisibleRange" Value="{scichart:AxesBinding XVisibleRange[1], Mode=TwoWay}" />
                                        </DataTrigger>
                                    </Style.Triggers>
                                </Style>

                            </scichart:NumericAxis>
                        </scichart:SciChartSurface.XAxis>

On the “value” of Setter I have only the following options:

  • AnnotationsBinding AxisBindingBinding MultiBindingCompatible
    SeriesBinding ThemeBinding VerticalLinesBinding

My question is:
Is there a way to binding “VisibleRange” on “Style.Triggers”?

Thank you,
Eduardo Arruda

0 votes
5k views

Hi,

We have the WPF 2D version.

We have bound the VisibleRange on both X and Y axes to our viewmodel.
A combo-box selection triggers the OnPropertyChanged which will assign a default range depending on the type of data we want to display.
We also have allowed for the user to drag the axes and adjust the ranges as desired.

This all works as we’d expect, until the user does a manual adjustment, then the binding to the combo-box seems to be broken (the default ranges we set for the given data no longer update the X and Y axes).

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