c# 图表与 LiveCharts 图像

Question

我有个小问题。我想将我的图表导出为图像。我知道这可以通过 beto-rodriguez ( here ) 给出的代码实现。

但我有一个问题，我无法通过在屏幕上显示它来拥有我可以拥有的东西。见上图。在右下角，我将图像保存为 png。在图像的左侧，我在我想要的位置显示了包含所有参数的图表。

您知道保存的图像中是否可能有相同的图表(在左侧)吗？实际上，我使用线程自动捕获(复制/粘贴)图像。

你知道我必须设置哪些参数才能获得正确的图像吗？

Double chart

提前致谢。问候。

********************************* 编辑后

抱歉我迟到的回复。我试试你说的，但不幸的是我做不到我想要的。我将解释我的工作:我有一个类“MakeReport”，可以调用另一个类“GraphMaker”:

MyGraph = new GraphMaker();
MyGraph = GiveAGraph(MyGraph);

“MakeReport”类将使用子程序“GiveAGraph()”用一些值完成图表:

GraphData.SeriesCollection.Add(new RowSeries
   {
       Title = Criteria, 
       Values = DataValues,
       ScalesYAt = Index,
       DataLabels = true
    });

“GiveAGRaph()”结束。

现在我有一张图表可以显示了，我想用它来制作图像并展示它进行测试(和调试):

// Chart to Image
MyGraph.GiveMeAnImageFromChart();      <-- to make a picture with the chart
// Show the graph
MyGraph.Show();                        <-- for debug and test, i display it.

使用“MyGraph.GiveAnImageFromChart()”，我得到的结果与“MyGraph.Show()”不同。图片(另存为 png)与显示的图表不同。

“GraphMaker”类中包含的子程序“GiveAnImageFromChart”是:

public void GiveMeAnImageFromChart()
    {
            var viewbox = new Viewbox();
            myChart.Background = Brushes.White;
            myChart.DataContext = this;

            // myChart  il faut tout mettre en paramètres

            viewbox.Child = myChart;
            viewbox.Measure(myChart.RenderSize);
            viewbox.Arrange(new Rect(new Point(0, 0), myChart.RenderSize));

            myChart.Update(true, true); //force chart redraw
            viewbox.UpdateLayout();

            SaveToPng(myChart, "chart.png");
            //png file was created at the root directory.

    }

“myChart”变量是公开的。使用的“SaveToPng”程序来自您的示例(here)。

为了保存图片，我尝试了以下方法:

public System.Drawing.Bitmap ControlToImage(Visual target, double dpiX, double dpiY)
    {
        if (target == null)
        {
            return null;
        }
        // render control content
        Rect bounds = VisualTreeHelper.GetDescendantBounds(target);
        Console.WriteLine("Bounds width = " + bounds.Width + " et bounds height = " + bounds.Height);
        RenderTargetBitmap rtb = new RenderTargetBitmap((int)(bounds.Width * dpiX / 96.0),
                                                        (int)(bounds.Height * dpiY / 96.0),
                                                        dpiX,
                                                        dpiY,
                                                        PixelFormats.Pbgra32);
        DrawingVisual dv = new DrawingVisual();
        using (DrawingContext ctx = dv.RenderOpen())
        {
            VisualBrush vb = new VisualBrush(target);
            ctx.DrawRectangle(vb, null, new Rect(new System.Windows.Point(), bounds.Size));
        }
        rtb.Render(dv);

        //convert image format
        MemoryStream stream = new MemoryStream();
        BitmapEncoder encoder = new BmpBitmapEncoder();
        encoder.Frames.Add(BitmapFrame.Create(rtb));
        encoder.Save(stream);

        return new System.Drawing.Bitmap(stream);
    }

与:

Bitmap ImageChart = MyGraph.ControlToImage(MyGraph, MyGraph.Width, MyGraph.Height);

使用此方法时，出现错误，因为“bounds.Width”和“bounds.Height”等于 -8。最后，我没有任何图表可以转换。

我想我在“ControlImage”中给出了一个错误的“视觉目标”，我错过了一些东西，但我不知道是什么。如果您需要更多信息，请问我。预先感谢您的帮助。

PS:对不起我的英语。请随时纠正我。

Answer 1

感谢 bto-rdz，我做了一个解决方案。我发现我没有正确使用 Livecharts。所以如果有人需要，我会发布我的代码。

这是我的 GraphMaker.xaml 文件:

<UserControl x:Class="MyProject.GraphMaker"
        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:MyProject"
        mc:Ignorable="d" 
        d:DesignHeight="730" d:DesignWidth="1660">
<Grid>
</Grid>
</UserControl>

还有我的 GraphMaker.xaml.cs 文件

    using System;
using System.IO;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using LiveCharts;
using LiveCharts.Wpf;
using System.Collections.Generic;
using System.ComponentModel;


namespace MyProject
{    
    public partial class GraphMaker : UserControl
    {
        // PUBLIC
        public CartesianChart MyTestChart;
        public SeriesCollection MySeriesCollection { get; set; }
        public string[] Labels { get; set; }
        public string AxisTitle { get; set; }
        public Func<double, string> YFormatter { get; set; }
        public Axis Axis1, Axis2, Axis3, Axis4, Axis5, Axis6, Axis7, Axis8, Axis9, Axis10, AxisXChart;


        public GraphMaker()
        {
            InitializeComponent();
            MySeriesCollection = new SeriesCollection();

            MyTestChart = new CartesianChart
            {
                DisableAnimations = true,
                Width = 1600,
                Height = 700,
                Series = MySeriesCollection
            };

            MyTestChart.LegendLocation = LegendLocation.Right;

            // *** Axis 1 ***
            Axis1 = new Axis();
            Axis1.Foreground = Brushes.DodgerBlue;
            Axis1.Position = AxisPosition.RightTop;
            YFormatter = value => value.ToString("N2");
            Axis1.LabelFormatter = YFormatter;
            MyTestChart.AxisY.Add(Axis1);

            // *** Axis 2 ***
            Axis2 = new Axis();
            Axis2.Foreground = Brushes.IndianRed;
            Axis2.Position = AxisPosition.RightTop;
            YFormatter = value => value.ToString("N2");
            Axis2.LabelFormatter = YFormatter;
            //MyTestChart.AxisY.Add(Axis2);

            // *** Axis 3 ***
            Axis3 = new Axis();
            Axis3.Foreground = Brushes.Gold;
            Axis3.Position = AxisPosition.RightTop;
            YFormatter = value => value.ToString("N2");
            Axis3.LabelFormatter = YFormatter;
            //MyTestChart.AxisY.Add(Axis3);

            // *** Axis 4 ***
            Axis4 = new Axis();
            Axis4.Foreground = Brushes.Gray;
            Axis4.Position = AxisPosition.RightTop;
            YFormatter = value => value.ToString("N2");
            Axis4.LabelFormatter = YFormatter;
            //MyTestChart.AxisY.Add(Axis4);

            // *** Axis 5 ***
            Axis5 = new Axis();
            Axis5.Foreground = Brushes.DeepSkyBlue;
            Axis5.Position = AxisPosition.RightTop;
            YFormatter = value => value.ToString("N2");
            Axis5.LabelFormatter = YFormatter;
            //MyTestChart.AxisY.Add(Axis5);

            // *** Axis 6 ***
            Axis6 = new Axis();
            Axis6.Foreground = Brushes.HotPink;
            Axis6.Position = AxisPosition.RightTop;
            YFormatter = value => value.ToString("N2");
            Axis6.LabelFormatter = YFormatter;
            //MyTestChart.AxisY.Add(Axis6);

            // *** Axis 7 ***
            Axis7 = new Axis();
            Axis7.Foreground = Brushes.Orange;
            Axis7.Position = AxisPosition.RightTop;
            YFormatter = value => value.ToString("N2");
            Axis7.LabelFormatter = YFormatter;
            //MyTestChart.AxisY.Add(Axis7);

            // *** Axis 8 ***
            Axis8 = new Axis();
            Axis8.Foreground = Brushes.RoyalBlue;
            Axis8.Position = AxisPosition.RightTop;
            YFormatter = value => value.ToString("N2");
            Axis8.LabelFormatter = YFormatter;
            //MyTestChart.AxisY.Add(Axis8);

            // *** Axis 9 ***
            Axis9 = new Axis();
            Axis9.Foreground = Brushes.Black;
            Axis9.Position = AxisPosition.RightTop;
            Axis9.LabelFormatter = YFormatter;
            //MyTestChart.AxisY.Add(Axis9);

            // *** Axis 10 ***
            Axis10 = new Axis();
            Axis10.Foreground = Brushes.DarkTurquoise;
            Axis10.Position = AxisPosition.RightTop;
            YFormatter = value => value.ToString("N2");
            Axis10.LabelFormatter = YFormatter;
            //MyTestChart.AxisY.Add(Axis10);

            AxisXChart = new Axis();
            AxisXChart.Title = AxisTitle;
            AxisXChart.Labels = Labels;
        }


        public void TakeTheChart()
        {
            var viewbox = new Viewbox();
            viewbox.Child = MyTestChart;
            viewbox.Measure(MyTestChart.RenderSize);
            viewbox.Arrange(new Rect(new Point(0, 0), MyTestChart.RenderSize));
            MyTestChart.Update(true, true); //force chart redraw
            viewbox.UpdateLayout();

            SaveToPng(MyTestChart, "Chart.png");
            //png file was created at the root directory.
        }

        public void SaveToPng(FrameworkElement visual, string fileName)
        {
            var encoder = new PngBitmapEncoder();
            EncodeVisual(visual, fileName, encoder);
        }

        private static void EncodeVisual(FrameworkElement visual, string fileName, BitmapEncoder encoder)
        {
            var bitmap = new RenderTargetBitmap((int)visual.ActualWidth, (int)visual.ActualHeight, 96, 96, PixelFormats.Pbgra32);
            bitmap.Render(visual);
            var frame = BitmapFrame.Create(bitmap);
            encoder.Frames.Add(frame);
            using (var stream = File.Create(fileName)) encoder.Save(stream);
        }
    }
}

希望能帮到你。

祝你有美好的一天。再见。