WPF InkCanvas绘制矩形和椭圆

ViewModel.cs代码

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Ink;
 
namespace WPF_InkCanvas
{
  class ViewModel : INotifyPropertyChanged
  {
    public event PropertyChangedEventHandler PropertyChanged;
 
    protected virtual void OnPropertyChanged(string propertyName = null)
    {
      if (PropertyChanged != null)
        PropertyChanged.Invoke(this, new PropertyChangedEventArgs(propertyName));
    }
 
    private string meaInfo;
    public string MeaInfo
    {
      get => meaInfo;
      set
      {
        meaInfo = value;
        OnPropertyChanged("MeaInfo");
      }
    }
 
    private StrokeCollection inkStrokes;
    public StrokeCollection InkStrokes
    {
      get { return inkStrokes; }
      set
      {
        inkStrokes = value;
        OnPropertyChanged("InkStrokes");
      }
    }
  }
}