WPF LiveChartsCore.SkiaSharpView.WPF Line and scatter points, save as jpg

Install-Package LiveChartsCore.SkiaSharpView.WPF -version 2.0.0-rc5.4

 

//xaml
<Window x:Class="WpfApp44.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:lvc="clr-namespace:LiveChartsCore.SkiaSharpView.WPF;assembly=LiveChartsCore.SkiaSharpView.WPF"
        xmlns:behavior="http://schemas.microsoft.com/xaml/behaviors"
        xmlns:local="clr-namespace:WpfApp44"
        WindowState="Maximized"
        mc:Ignorable="d"
        Title="MainWindow" Height="450" Width="800">
    <behavior:Interaction.Triggers>
        <behavior:EventTrigger EventName="MouseLeftButtonDown">
            <behavior:InvokeCommandAction Command="{Binding MouseLeftButtonDownCommand}"/>
        </behavior:EventTrigger>
    </behavior:Interaction.Triggers>
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition/>
            <RowDefinition/>
        </Grid.RowDefinitions>
        <Grid.ColumnDefinitions>
            <ColumnDefinition/>
            <ColumnDefinition/>
        </Grid.ColumnDefinitions>
        <lvc:CartesianChart
            Background="White"
            Grid.Row="0"
            Grid.Column="0"
            Grid.RowSpan="2"
            Series="{Binding XYLineSeries}"
            XAxes="{Binding XValues}"
            YAxes="{Binding YValues}">
            <lvc:CartesianChart.ContextMenu>
                <ContextMenu>
                    <MenuItem Header="Save As Jpg"
                              Command="{Binding SaveAsJpgCommand}"
                              CommandParameter="{Binding RelativeSource={RelativeSource Mode=FindAncestor,AncestorType={x:Type ContextMenu}},
                        Path=PlacementTarget}"/>
                </ContextMenu>
            </lvc:CartesianChart.ContextMenu>
        </lvc:CartesianChart>

        <lvc:CartesianChart
            Background="White"
            Grid.Row="0"
            Grid.Column="1"
            Grid.RowSpan="2"
            Margin="50,0,0,0"
            Series="{Binding XYScatterSeries}"
            XAxes="{Binding XValues}"
            YAxes="{Binding YValues}">
            <lvc:CartesianChart.ContextMenu>
                <ContextMenu>
                    <MenuItem Header="Save As Jpg"
                   Command="{Binding SaveAsJpgCommand}"
                   CommandParameter="{Binding RelativeSource={RelativeSource Mode=FindAncestor,AncestorType={x:Type ContextMenu}},
             Path=PlacementTarget}"/>
                </ContextMenu>
            </lvc:CartesianChart.ContextMenu>
        </lvc:CartesianChart>
    </Grid>
</Window>


//cs
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
using LiveChartsCore.SkiaSharpView;
using System.Drawing;
using LiveChartsCore;
using LiveChartsCore.Defaults;
using LiveChartsCore.SkiaSharpView.Painting;
using SkiaSharp;
using System.ComponentModel;
using System.Runtime.CompilerServices;
using LiveChartsCore.SkiaSharpView.WPF;
using System.IO;
using System.Diagnostics;


namespace WpfApp44
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();

            var vm = new MainVM();
            this.DataContext=vm;
        }
    }


    public class MainVM : INotifyPropertyChanged
    {
        private ISeries[] xYLineSeries;
        public ISeries[] XYLineSeries
        {
            get
            {
                return xYLineSeries;
            }
            set
            {
                if(value!=xYLineSeries)
                {
                    xYLineSeries = value;
                    OnPropertyChanged();
                }
            }
        }


        private ISeries[] xYScatterSeries;
        public ISeries[] XYScatterSeries
        {
            get
            {
                return xYScatterSeries;
            }
            set
            {
                if(value!=xYScatterSeries)
                {
                    xYScatterSeries=value;
                    OnPropertyChanged();
                }
            }
        }

        public Axis[] XValues { get; set; }
        public Axis[] YValues { get; set; }

        public List<ObservablePoint> DataPoints { get; } = new List<ObservablePoint>();

        Random rnd = new Random();

        public event PropertyChangedEventHandler? PropertyChanged;
        private void OnPropertyChanged([CallerMemberName] string propName = "")
        {
            var handler = PropertyChanged;
            if (handler!=null)
            {
                handler?.Invoke(this, new PropertyChangedEventArgs(propName));
            }
        }

        private int dpiFactor = 2;

        public MainVM()
        {
            XValues=new Axis[]
            {
                new Axis
                {
                    Name="X Axis",
                    Labeler=value=>value.ToString("N")
                }
            };

            YValues=new Axis[]
            {
                new Axis
                {
                    Name="Y Axis",
                    Labeler=value=>value.ToString("N2")
                }
            };

            InitData();
        }

        private void InitData()
        {
            DataPoints.Clear();
            for (int i = 0; i<10; i++)
            {
                DataPoints.Add(new ObservablePoint(i, rnd.NextDouble()*10));
            }

            XYLineSeries=new ISeries[]
            {
                new LineSeries<ObservablePoint>
                {
                    Values=DataPoints,
                    Stroke=new SolidColorPaint(SKColors.Blue)
                    {
                        StrokeThickness=2
                    },
                    Fill=null,
                    GeometryStroke=null,
                    GeometryFill=null
                }
            };

            XYScatterSeries=new ISeries[]
            {
                new ScatterSeries<ObservablePoint>
                {
                    Values=DataPoints,
                    Stroke=null,
                    Fill=new SolidColorPaint(SKColors.Red),
                    GeometrySize=10
                }
            };
        }

        private ICommand mouseLeftButtonDownCommand;

        public ICommand MouseLeftButtonDownCommand
        {
            get
            {
                if (mouseLeftButtonDownCommand==null)
                {
                    mouseLeftButtonDownCommand=new DelCommand(MouseLeftButtonDownCommandExecuted);
                }
                return mouseLeftButtonDownCommand;
            }
        }

        private void MouseLeftButtonDownCommandExecuted(object? obj)
        {
            InitData();
        }

        private ICommand saveAsJpgCommand;
        public ICommand SaveAsJpgCommand
        {
            get
            {
                if(saveAsJpgCommand==null)
                {
                    saveAsJpgCommand=new DelCommand(SaveAsJpgCommandExecuted);
                }
                return saveAsJpgCommand;
            }
        }

        private void SaveAsJpgCommandExecuted(object? obj)
        {
            var fe = obj as FrameworkElement;
            if(fe!=null)
            {
                SaveFrameworkElementAsJpg(fe);
            }
        }

        public void SaveFrameworkElementAsJpg(FrameworkElement fe)
        {
            if(fe==null)
            {
                return;
            }

            int feWidth=(int)fe.ActualWidth;
            int feHeight=(int)fe.ActualHeight;

            RenderTargetBitmap rtb = new RenderTargetBitmap(feWidth*dpiFactor, feHeight*dpiFactor,
                96*dpiFactor, 96*dpiFactor, PixelFormats.Pbgra32);

            DrawingVisual drawingVisual=new DrawingVisual();
            using (DrawingContext drawingContext = drawingVisual.RenderOpen())
            {
                VisualBrush visualBrush = new VisualBrush(fe);
                drawingContext.DrawRectangle(visualBrush, null, new Rect(0, 0, feWidth, feHeight));
            }

            rtb.Render(drawingVisual);

            JpegBitmapEncoder encoder = new JpegBitmapEncoder();
            encoder.Frames.Add(BitmapFrame.Create(rtb));

            string jpgFile = $"Chart_{DateTime.Now.ToString("yyyyMMddHHmmssffff")}{Guid.NewGuid().ToString("N")}.jpg";
            using (FileStream fileStream = new FileStream(jpgFile, FileMode.Create))
            {
                encoder.Save(fileStream);
            }

            var proc = new Process
            {
                StartInfo=new ProcessStartInfo()
                {
                    FileName= jpgFile,
                    UseShellExecute=true
                }
            };
            proc.Start();
        }
    }

    public class DelCommand : ICommand
    {
        private readonly Action<object?> execute;
        private readonly Predicate<object?> canExecute;

        public DelCommand(Action<object?> executeValue, Predicate<object?> canExecuteValue = null)
        {
            execute = executeValue;
            canExecute = canExecuteValue;
        }

        public event EventHandler? CanExecuteChanged
        {
            add
            {
                CommandManager.RequerySuggested += value;
            }
            remove
            {
                CommandManager.RequerySuggested -=value;
            }
        }

        public bool CanExecute(object? parameter)
        {
            return canExecute==null ? true : canExecute(parameter);
        }

        public void Execute(object? parameter)
        {
            execute(parameter);
        }
    }

}