wpf 图像浏览（平移，缩放）

<Window
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        x:Class="WpfApp2.MainWindow"
        mc:Ignorable="d"
        Title="MainWindow" Height="800" Width="1000">

    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="*"/>
            <RowDefinition Height="40"/>
        </Grid.RowDefinitions>
        <Border x:Name="outside" Background="Black" 
                PreviewMouseDown="outsidewrapper_PreviewMouseDown" 
                PreviewMouseMove="outsidewrapper_PreviewMouseMove" 
                PreviewMouseUp="outside_PreviewMouseUp"
                PreviewMouseWheel="outside_PreviewMouseWheel"
                ClipToBounds="True">

            <Canvas x:Name="inside" Width="{Binding ActualWidth, RelativeSource={RelativeSource AncestorType={x:Type Border}}}" 
                    Height="{Binding ActualHeight, RelativeSource={RelativeSource AncestorType={x:Type Border}}}">
                <Canvas.RenderTransform>
                    <TransformGroup/>
                </Canvas.RenderTransform>
                <Image x:Name="myImage" Source="{Binding IamgeSource}" Stretch="Uniform" RenderOptions.BitmapScalingMode="NearestNeighbor" >
                    <Image.RenderTransform >
                        <ScaleTransform x:Name="ImageScale"/>
                    </Image.RenderTransform>
                </Image>
            </Canvas>
        </Border>
        <Button Click="BtnClickLoadPic" Grid.Row="2" HorizontalAlignment="Right" Content="加载图片" />
        <Button Click="BtnClickFullScreen" Grid.Row="2" HorizontalAlignment="Right" Content="   全屏   " Margin="0,0,60,0" />

    </Grid>

</Window>

using GalaSoft.MvvmLight;
using GalaSoft.MvvmLight.Messaging;
using LiveCharts;
using LiveCharts.Wpf;
using MathNet.Numerics.LinearAlgebra.Double;
using Microsoft.Win32;
//using MathNet.Numerics.LinearAlgebra.Complex;
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
namespace WpfApp2
{
    /// <summary>
    /// MainWindow.xaml 的交互逻辑
    /// </summary>
    public partial class MainWindow : Window
    {
        Point previousPoint;
        bool isTranslateStart = false;
        public MainWindow()
        {
            InitializeComponent();
        }

        private void outsidewrapper_PreviewMouseDown(object sender, MouseButtonEventArgs e)
        {
            if (e.MiddleButton == MouseButtonState.Pressed && e.LeftButton == MouseButtonState.Released && e.RightButton == MouseButtonState.Released)
            {
                previousPoint = e.GetPosition(outside);
                isTranslateStart = true;
            }
            e.Handled = true;
        }

        private void outsidewrapper_PreviewMouseMove(object sender, MouseEventArgs e)
        {
            if (e.MiddleButton == MouseButtonState.Pressed && e.LeftButton == MouseButtonState.Released && e.RightButton == MouseButtonState.Released)
            {
                if (isTranslateStart)
                {
                    Point currentPoint = e.GetPosition(outside);  //不能用 inside，必须用outside
                    System.Windows.Vector v = currentPoint - previousPoint;
                    TransformGroup tg = inside.RenderTransform as TransformGroup;
                    tg.Children.Add(new TranslateTransform(v.X, v.Y));  //centerX和centerY用外部包装元素的坐标，不能用内部被变换的Canvas元素的坐标
                    previousPoint = currentPoint;
                }
            }
            e.Handled = true;
        }

        private void outside_PreviewMouseUp(object sender, MouseButtonEventArgs e)
        {
            if (e.MiddleButton == MouseButtonState.Pressed && e.LeftButton == MouseButtonState.Released && e.RightButton == MouseButtonState.Released)
            {
                if (isTranslateStart)
                {
                    isTranslateStart = false;
                }
            }
            e.Handled = true;
        }
        private void outside_PreviewMouseWheel(object sender, MouseWheelEventArgs e)
        {
            Point currentPoint = e.GetPosition(outside);  //不能用 inside，必须用outside
            TransformGroup tg = inside.RenderTransform as TransformGroup;
            double s = ((double)e.Delta) / 1000.0 + 1.0;
            if (myImage.Height * tg.Value.M22 < 200 || myImage.Width * tg.Value.M11 < 200)
            {
                if(s > 1.0)//当图像像素宽度和高度小于200的时候只能放大，不再缩小
                    tg.Children.Add(new ScaleTransform(s, s, currentPoint.X, currentPoint.Y));
            }
            else
                tg.Children.Add(new ScaleTransform(s, s, currentPoint.X, currentPoint.Y));
            e.Handled = true;
        }

        private void BtnClickLoadPic(object sender, RoutedEventArgs e)
        {
            // Instantiate the dialog box
            var dlg = new Microsoft.Win32.OpenFileDialog
            {
                FileName = "",
                Filter = "All Files|*.*|PNG Files|*.png|JPG Files|*.jpg|TIF Files|*.tif"
            };
            var result = dlg.ShowDialog();
            // Process open file dialog box results
            if (result == true)
            {
                BitmapImage bitmapImage = new BitmapImage(new Uri(dlg.FileName));
                myImage.Source = bitmapImage;
                myImage.Height = bitmapImage.PixelHeight;//为了得到像素对应的坐标
                myImage.Width = bitmapImage.PixelWidth;//为了得到像素对应的坐标
            }
        }

        private void BtnClickFullScreen(object sender, RoutedEventArgs e)
        {
            TransformGroup tg = inside.RenderTransform as TransformGroup;
            System.Windows.Media.Matrix value = new System.Windows.Media.Matrix();
            value.M11 = outside.ActualWidth / myImage.Width / tg.Value.M11;//缩放倍数为Border的尺寸
            value.M22 =  outside.ActualHeight / myImage.Height / tg.Value.M22;
            value.OffsetX = (0 - tg.Value.OffsetX) * value.M11;//调整偏移XY到（0，0）
            value.OffsetY = (0 - tg.Value.OffsetY) * value.M22;
            MatrixTransform matrixTransform = new MatrixTransform(value);//添加矩阵变换
            tg.Children.Add(matrixTransform);
            e.Handled = true;
        }
    }
}