从 ColumnSeries 中删除项目

Question

如何使用 Oxyplot 从给定的 ColumnSeries 中删除项目？

鉴于代码是库本身提供的示例（稍作修改），以及某种删除事件（我自己可以弄清楚），我将如何删除一个项目（专栏）从图中？

如果我只是从 bar.Items 列表中删除该项目，标签将不会消失。从 tmp.Axes[0].ActualLabels（即 CategoryAxis）中删除它不会 "refresh" 视图，并且标签保留在那里。这种情况有什么解决办法吗？我已经设法用折线图和饼图做到了，但我在第一列上苦苦挣扎。

构建图形的代码隐藏：

namespace ColumnSeriesDemo
{
    using System.Collections.ObjectModel;
    using System.Windows;

    using OxyPlot;
    using OxyPlot.Axes;
    using OxyPlot.Series;

    using WpfExamples;

    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    [Example("Shows column series.")]
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            this.InitializeComponent();

            // Create some data
            this.Items = new Collection<Item>
                            {
                                new Item {Label = "Apples", Value1 = 37, Value2 = 12, Value3 = 19},
                                new Item {Label = "Pears", Value1 = 7, Value2 = 21, Value3 = 9},
                                new Item {Label = "Bananas", Value1 = 23, Value2 = 2, Value3 = 29}
                            };

            // Create the plot model
            var tmp = new PlotModel { Title = "Column series", LegendPlacement = LegendPlacement.Outside, LegendPosition = LegendPosition.RightTop, LegendOrientation = LegendOrientation.Vertical };

            // Add the axes, note that MinimumPadding and AbsoluteMinimum should be set on the value axis.
            tmp.Axes.Add(new CategoryAxis { ItemsSource = this.Items, LabelField = "Label" });
            tmp.Axes.Add(new LinearAxis { Position = AxisPosition.Left, MinimumPadding = 0, AbsoluteMinimum = 0 });

            // Add the series, note that the BarSeries are using the same ItemsSource as the CategoryAxis.
            ColumnSeries bar = new ColumnSeries();
            tmp.Series.Add(bar);
            bar.Items.Add(new ColumnItem { Color = OxyPlot.OxyColors.Yellow, Value = this.Items[0].Value3, CategoryIndex = 0 });
            bar.Items.Add(new ColumnItem { Color = OxyPlot.OxyColors.Green, Value = this.Items[0].Value2, CategoryIndex = 2 });
            bar.Items.Add(new ColumnItem { Color = OxyPlot.OxyColors.Red, Value = this.Items[0].Value1, CategoryIndex = 3 });


            this.Model1 = tmp;

            this.DataContext = this;
        }

        public Collection<Item> Items { get; set; }

        public PlotModel Model1 { get; set; }
    }

    public class Item
    {
        public string Label { get; set; }
        public double Value1 { get; set; }
        public double Value2 { get; set; }
        public double Value3 { get; set; }
    }
}

Answer 1

我不太确定我知道你想做什么，但我希望这对你有帮助：

我拿了示例并围绕您的代码和示例进行了一些播放。我认为您的代码的问题在于您在 CategoryAxis 中有一个绑定，但数据不是通过绑定添加的，而是直接在您的 ColumnSeries 中添加的。使用您的代码，我将第一部分保留原样，而不是 ColumnSeries bar = new ColumnSeries() 我做了：

        ColumnSeries bar = new ColumnSeries
        {
            FillColor = OxyPlot.OxyColors.Yellow,
            ValueField = "Value1",
            Title = "Value1",
            ItemsSource = Items
        };
        tmp.Series.Add(bar);

这样，Items 中的数据在您的 CategoryAxis 和 ColumnSeries 中都被绑定（当然，如果您需要更多代表 Value2 和 Value3 Items 的值 class 您可以将新的 ColumnSeries 添加到您的 PlotModel 的系列中）

然后我在Window中添加了一个按钮，并在代码隐藏中添加：

        Items.RemoveAt(0);
        Model1.InvalidatePlot(true);

这会更新 Plot，删除（每次）第一个 ColumnSeries，包括 CategoryAxis 中的 Label。

Window 代码隐藏：

using System.Collections.ObjectModel;
using System.Windows;
using OxyPlot;
using OxyPlot.Axes;
using OxyPlot.Series;

namespace OxyPlot_TEST
{
    /// <summary>
    /// Interaction logic for Window2.xaml
    /// </summary>
    public partial class Window2 : Window
    {
        public Window2()
        {
            InitializeComponent();

            // Create some data
            this.Items = new Collection<Item>
                            {
                                new Item {Label = "Apples", Value1 = 37, Value2 = 12, Value3 = 19},
                                new Item {Label = "Pears", Value1 = 7, Value2 = 21, Value3 = 9},
                                new Item {Label = "Bananas", Value1 = 23, Value2 = 2, Value3 = 29}
                            };

            // Create the plot model
            var tmp = new PlotModel { Title = "Column series", LegendPlacement = LegendPlacement.Outside, LegendPosition = LegendPosition.RightTop, LegendOrientation = LegendOrientation.Vertical };

            // Add the axes, note that MinimumPadding and AbsoluteMinimum should be set on the value axis.
            tmp.Axes.Add(new CategoryAxis { ItemsSource = this.Items, LabelField = "Label" });
            tmp.Axes.Add(new LinearAxis { Position = AxisPosition.Left, MinimumPadding = 0, AbsoluteMinimum = 0 });

            ColumnSeries bar = new ColumnSeries
            {
                FillColor = OxyPlot.OxyColors.Yellow,
                ValueField = "Value1",
                Title = "Value1",
                ItemsSource = Items
            };
            ColumnSeries bar1 = new ColumnSeries
            {
                FillColor = OxyPlot.OxyColors.Green,
                ValueField = "Value1",
                Title = "Value1",
                ItemsSource = Items
            };
            ColumnSeries bar2 = new ColumnSeries
            {
                FillColor = OxyPlot.OxyColors.Red,
                ValueField = "Value1",
                Title = "Value1",
                ItemsSource = Items
            };
            tmp.Series.Add(bar);
            tmp.Series.Add(bar1);
            tmp.Series.Add(bar2);

            this.Model1 = tmp;
            this.DataContext = this;
        }

        public Collection<Item> Items { get; set; }

        public PlotModel Model1 { get; set; }

        private void button1_Click(object sender, RoutedEventArgs e)
        {
            Items.RemoveAt(0);
            Model1.InvalidatePlot(true);
        }
    }

    public class Item
    {
        public string Label { get; set; }
        public double Value1 { get; set; }
        public double Value2 { get; set; }
        public double Value3 { get; set; }
    }
}

<<--------------------------------编辑-------- ---------------------->>

如果每个类别只需要一个栏，则每个项目只需要一个值。然后您可以（如前例所示）删除甚至添加项目 from/to 集合（使用 InvalidatePlot 更新绘图。代码隐藏：

using System.Collections.ObjectModel;
using System.Windows;
using OxyPlot;
using OxyPlot.Axes;
using OxyPlot.Series;

namespace OxyPlot_TEST
{
    /// <summary>
    /// Interaction logic for Window2.xaml
    /// </summary>
    public partial class Window2 : Window
    {
        public Window2()
        {
            InitializeComponent();

            // Create some data
            this.Items = new Collection<Item>
                            {
                                new Item {Label = "Apples", Value1 = 37},
                                new Item {Label = "Pears", Value1 = 7},
                                new Item {Label = "Bananas", Value1 = 23}
                            };

            // Create the plot model
            var tmp = new PlotModel { Title = "Column series", LegendPlacement = LegendPlacement.Outside, LegendPosition = LegendPosition.RightTop, LegendOrientation = LegendOrientation.Vertical };

            // Add the axes, note that MinimumPadding and AbsoluteMinimum should be set on the value axis.
            tmp.Axes.Add(new CategoryAxis { ItemsSource = this.Items, LabelField = "Label" });
            tmp.Axes.Add(new LinearAxis { Position = AxisPosition.Left, MinimumPadding = 0, AbsoluteMinimum = 0 });

            ColumnSeries bar = new ColumnSeries
            {
                FillColor = OxyPlot.OxyColors.Black,
                ValueField = "Value1",
                Title = "Value1",
                ItemsSource = Items
            };
            tmp.Series.Add(bar);

            this.Model1 = tmp;
            this.DataContext = this;
        }

        public Collection<Item> Items { get; set; }

        public PlotModel Model1 { get; set; }

        private void button1_Click(object sender, RoutedEventArgs e)
        {
            Items.RemoveAt(0);
            Model1.InvalidatePlot(true);
        }

        private void button2_Click(object sender, RoutedEventArgs e)
        {
            Items.Add(new Item()
            {
                Label = "Strawberrys", Value1 = 55
            });
            Model1.InvalidatePlot(true);
        }
    }

    public class Item
    {
        public string Label { get; set; }
        public double Value1 { get; set; }
    }
}

从 ColumnSeries 中删除项目

Remove item from ColumnSeries

c#

wpf

bar-chart

oxyplot