C# 形式：OxyPlot饼图内的可移动标签

你好。我正在创建一个Xamarin.Forms便携式应用程序，在那里我可以使用OxyPlot显示图表

我的问题是：

1。）每当我试图将标签放在图表附近的某个位置时，无论何时我在屏幕上滑动，标签似乎都是可移动的

2。）我无法删除图表周围的黑色边框

你认为这背后的原因是什么？非常感谢

这是我的密码：

using OxyPlot;
using OxyPlot.Annotations;
using OxyPlot.Axes;
using OxyPlot.Series;
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Runtime.CompilerServices;
using System.Text;
using System.Threading.Tasks;


namespace XamarinFormsDemo.ViewModels
{
   public class SalesPerProductViewModel : INotifyPropertyChanged
    {
    private PlotModel modelP1;
    SalesVM salesVM = new SalesVM();

    public SalesPerProductViewModel()
    {
        // PieViewModel vm = new PieViewModel();

        modelP1 = new PlotModel
        {
            Title = "Sales Per Product",
            TitleColor = OxyColors.Teal,
            TitleFontSize = 30,
            TextColor = OxyColors.White,
            DefaultFont = "Arial Black",
            DefaultFontSize = 20

        };

        TextAnnotation annotation = new TextAnnotation();
        annotation.Text = "Total Sales Label: ";
        annotation.TextColor = OxyColors.White;
        annotation.Stroke = OxyColors.Transparent;
        annotation.StrokeThickness = 5;
        annotation.FontSize = 20;
        annotation.TextPosition = new DataPoint(30, 90);

        modelP1.Annotations.Add(annotation);

        modelP1.Axes.Add(new LinearAxis() { Position = AxisPosition.Bottom, IsAxisVisible = false });
        modelP1.Axes.Add(new LinearAxis() { Position = AxisPosition.Left, IsAxisVisible = false });
        // modelP1.Annotations.Add(annotation);





        dynamic seriesP1 = new PieSeries { StrokeThickness = 2.0, InsideLabelPosition = 0.8, AngleSpan = 360, StartAngle = 0 };
      //  seriesP1.Add(salesVM.SalesModelvm);



        seriesP1.Slices.Add(new PieSlice("Keyboard", 5900) { IsExploded = false, Fill = OxyColors.Teal });
        seriesP1.Slices.Add(new PieSlice("Monitor", 4430) { IsExploded = true });
        seriesP1.Slices.Add(new PieSlice("Flash Drive", 11620) { IsExploded = true });
        seriesP1.Slices.Add(new PieSlice("Hard Drive", 7000) { IsExploded = true });
        seriesP1.Slices.Add(new PieSlice("RAM", 8000) { IsExploded = true });

        modelP1.Series.Add(seriesP1);
        this.SalesPerProductModel = modelP1;

    }

    public PlotModel SalesPerProductModel { get; private set; }


    public event PropertyChangedEventHandler PropertyChanged;

    protected void OnPropertyChanged([CallerMemberName] string propertyName = null)
    {
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
        }

    }
}