Move a rectangle around a canvas

Question

I have a canvas in the middle of my application with controls around it. I have a socket that recieves Points and saves them in a list.

I draw small 4x4 rectangles on th

Answer 1

I think more nifty solutions are available through binding the Canvas.Left and Canvas.Top attached properties to a ObservableCollection>, but as you asked for an old fashioned WinForms Style solution here you have something that does what I think you need (My apologies for writing this in C#):

XAML:

    
        
            
        
        Move Random Point
        Add Point
        Remove Random Point
    

Code behind:

using System;
using System.Collections.Generic;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Media;
using System.Windows.Shapes;

namespace MovingPointsSpike
{

    public partial class MainWindow : Window
    {
        private List m_Points;
        private Random m_Random;

        public MainWindow()
        {
            InitializeComponent();
            m_Points=new List();
            m_Random=new Random();
        }

        private void Move_Click(object sender, RoutedEventArgs e)
        {
            Rectangle rectangle;
            Point newPoint;
            int index = GetRandomIndex();
            newPoint = GetRandomPoint();

            rectangle =(Rectangle)PointCanvas.Children[index];
            if (index == -1) return;
            Canvas.SetTop(rectangle, newPoint.Y);
            Canvas.SetLeft(rectangle, newPoint.X);
        }

        private void Add_Click(object sender, RoutedEventArgs e)
        {
            Point newPoint;
            Rectangle rectangle;

            newPoint = GetRandomPoint();
            rectangle = new Rectangle {Width = 4, Height = 4, Fill = Brushes.Red};
            m_Points.Add(newPoint);
            PointCanvas.Children.Add(rectangle);
            Canvas.SetTop(rectangle,newPoint.Y);
            Canvas.SetLeft(rectangle,newPoint.X);
        }

        private Point GetRandomPoint()
        {
            int x;
            int y;
            x = m_Random.Next(10, 490);
            y = m_Random.Next(10, 490);
            return new Point(x,y);
        }

        private void Remove_Click(object sender, RoutedEventArgs e)
        {
            int index = GetRandomIndex();
            if (index==-1)return;

            PointCanvas.Children.RemoveAt(index);
            m_Points.RemoveAt(index);

        }

        private int GetRandomIndex()
        {
            int index;
            if (m_Points.Count==0) return -1;
            index = m_Random.Next(m_Points.Count - 1);
            return index;
        }
    }
}