100分求WPF中MVVM实现office幻灯片中画矩形的功能


5. 每话一个矩形都会在右侧的选择和可见性窗口显示相应矩形的属性，如图所示：：

6. 右下角，可以对Canvas进行放大缩小，要的是圆形按钮


求大神指点，顺便练练笔吧
[解决办法]
1、

using System;
using System.Collections.Generic;
using System.Text;
using System.Windows.Controls;
using System.Windows.Media;
using System.Windows;
using System.Globalization;

namespace CustomPaint
{
    class MyCanvas : Canvas
    {
        protected override void OnRender(DrawingContext dc)
        {
            base.OnRender(dc);

            dc.DrawRectangle(Brushes.LightBlue, new Pen(Brushes.Red, 1), 
                new Rect(new Point(10, 10), new Size(100, 50)));

            dc.DrawText(new FormattedText("my canvas", CultureInfo.CurrentCulture, 
                FlowDirection.LeftToRight, new Typeface("Tahoma"), 20, Brushes.Green),
                new Point(50,25));
        }
    }
}

[解决办法]
http://www.codeproject.com/KB/WPF/WPFDiagramDesigner_Part1.aspx