Xamarin图表开发基础教程（6）OxyPlot框架

Xamamin iOS中绘制线图OxyPlotiOSDemo

【示例OxyPlotiOSDemo】下面将实现线图的显示。具体的操作步骤如下：

（1）打开Xamarin.iOS项目。

（2）将OxyPlot.Xamarin.iOS组件添加到项目中的引入中。

（3）打开ViewController.cs文件，完成剩余的步骤，即创建PlotView视图、绘制图表、设置显示模式以及显示PlotView。代码如下：

using Foundation;

using System;

using UIKit;

using OxyPlot.Xamarin.iOS;

using OxyPlot;

using OxyPlot.Axes;

using OxyPlot.Series;

namespace OxyPlotiOSDemo

{

    public partial class ViewController : UIViewController

    {

        public ViewController (IntPtr handle) : base (handle)

        {

        }

        public override void ViewDidLoad ()

        {

            base.ViewDidLoad ();

            // Perform any additional setup after loading the view, typically from a nib.

            //创建PlotView视图

            PlotView plotView = new PlotView

            {

                Frame = this.View.Frame

            };

            plotView.Model=CreatePlotModel();                                                    //设置显示模式

            this.View.Add(plotView);                                                                        //将PlotView视图添加到主视图上

        }

        //绘制图表

        private PlotModel CreatePlotModel()

        {

            //创建图表模式

            var plotModel = new PlotModel

            {

                Title = "OxyPlot Demo"

            };

            //添加坐标轴

            plotModel.Axes.Add(new LinearAxis { Position = AxisPosition.Bottom });

            plotModel.Axes.Add(new LinearAxis { Position = AxisPosition.Left, Maximum = 10, Minimum = 0 });

            //创建数据列

            var series1 = new LineSeries

            {

                Title = "Data",

                MarkerType = MarkerType.Circle,

                MarkerSize = 4,

                MarkerStroke = OxyColors.White

            };

            //添加数据点

            series1.Points.Add(new DataPoint(0.0, 6.0));

            series1.Points.Add(new DataPoint(1.4, 2.1));

            series1.Points.Add(new DataPoint(2.0, 4.2));

            series1.Points.Add(new DataPoint(3.3, 2.3));

            series1.Points.Add(new DataPoint(4.7, 7.4));

            series1.Points.Add(new DataPoint(6.0, 6.2));

            series1.Points.Add(new DataPoint(8.9, 8.9));

            //添加数据列

            plotModel.Series.Add(series1);

            return plotModel;

        }

        ……

    }

}

运行程序，会看到如图1.2所示的效果。

图1.2  Xamarin.iOS平台的线图效果