稳扎稳打Silverlight(5) - 2.0控件之ListBox, MediaElement, MultiScaleImage, PasswordBox

using System; 
using System.Collections.Generic; 
using System.Linq; 
using System.Net; 
using System.Windows; 
using System.Windows.Controls; 
using System.Windows.Documents; 
using System.Windows.Input; 
using System.Windows.Media; 
using System.Windows.Media.Animation; 
using System.Windows.Shapes; 
 
namespace Silverlight20.Control 
{ 
         public partial  class MultiScaleImage : UserControl 
        { 
                 // 
                 // Based on prior work done by Lutz Gerhard, Peter Blois, and Scott Hanselman 
                 // 
                Point lastMousePos =  new Point(); 
 
                 double _zoom = 1; 
                 bool mouseButtonPressed =  false; 
                 bool mouseIsDragging =  false; 
                Point dragOffset; 
                Point currentPosition; 
 
                 public  double ZoomFactor 
                { 
                        get {  return _zoom; } 
                        set { _zoom = value; } 
                } 
 
                 public MultiScaleImage() 
                { 
                        InitializeComponent(); 
 
                         // 
                         // We are setting the source here, but you should be able to set the Source property via 
                         // 
                         this.msi.Source =  new DeepZoomImageTileSource( new Uri( "/DeepZoomImages/dzc_output.xml", UriKind.Relative)); 
 
                         // 
                         // Firing an event when the MultiScaleImage is Loaded 
                         // 
                         this.msi.Loaded +=  new RoutedEventHandler(msi_Loaded); 
 
                         // 
                         // Firing an event when all of the images have been Loaded 
                         // 
                         this.msi.ImageOpenSucceeded +=  new RoutedEventHandler(msi_ImageOpenSucceeded); 
 
                         // 
                         // Handling all of the mouse and keyboard functionality 
                         // 
                         this.MouseMove +=  delegate( object sender, MouseEventArgs e) 
                        { 
                                 if (mouseButtonPressed) 
                                { 
                                        mouseIsDragging =  true; 
                                } 
                                 this.lastMousePos = e.GetPosition( this.msi); 
                        }; 
 
                         this.MouseLeftButtonDown +=  delegate( object sender, MouseButtonEventArgs e) 
                        { 
                                mouseButtonPressed =  true; 
                                mouseIsDragging =  false; 
                                dragOffset = e.GetPosition( this); 
                                currentPosition = msi.ViewportOrigin; 
                        }; 
 
                         this.msi.MouseLeave +=  delegate( object sender, MouseEventArgs e) 
                        { 
                                mouseIsDragging =  false; 
                        }; 
 
                         this.MouseLeftButtonUp +=  delegate( object sender, MouseButtonEventArgs e) 
                        { 
                                mouseButtonPressed =  false; 
                                 if (mouseIsDragging ==  false) 
                                { 
                                         bool shiftDown = (Keyboard.Modifiers & ModifierKeys.Shift) == ModifierKeys.Shift; 
 
                                        ZoomFactor = 2.0; 
                                         if (shiftDown) ZoomFactor = 0.5; 
                                        Zoom(ZoomFactor,  this.lastMousePos); 
                                } 
                                mouseIsDragging =  false; 
                        }; 
 
                         this.MouseMove +=  delegate( object sender, MouseEventArgs e) 
                        { 
                                 if (mouseIsDragging) 
                                { 
                                        Point newOrigin =  new Point(); 
                                        newOrigin.X = currentPosition.X - (((e.GetPosition(msi).X - dragOffset.X) / msi.ActualWidth) * msi.ViewportWidth); 
                                        newOrigin.Y = currentPosition.Y - (((e.GetPosition(msi).Y - dragOffset.Y) / msi.ActualHeight) * msi.ViewportWidth); 
                                        msi.ViewportOrigin = newOrigin; 
                                } 
                        }; 
 
                         new MouseWheelHelper( this).Moved +=  delegate( object sender, MouseWheelEventArgs e) 
                        { 
                                e.Handled =  true; 
                                 if (e.Delta > 0) 
                                        ZoomFactor = 1.2; 
                                 else 
                                        ZoomFactor = .80; 
 
                                Zoom(ZoomFactor,  this.lastMousePos); 
                        }; 
                } 
 
                 void msi_ImageOpenSucceeded( object sender, RoutedEventArgs e) 
                { 
                         //If collection, this gets you a list of all of the MultiScaleSubImages 
                         // 
                         //foreach (MultiScaleSubImage subImage in msi.SubImages) 
                         //{ 
                         //        // Do something 
                         //} 
                } 
 
                 void msi_Loaded( object sender, RoutedEventArgs e) 
                { 
                         // Hook up any events you want when the image has successfully been opened 
                } 
 
                 public  void Zoom( double zoom, Point pointToZoom) 
                { 
                        Point logicalPoint =  this.msi.ElementToLogicalPoint(pointToZoom); 
                         this.msi.ZoomAboutLogicalPoint(zoom, logicalPoint.X, logicalPoint.Y); 
                } 
 
                 /* 
                 *    Sample event handlerrs tied to the Click of event of various buttons for    
                 *    showing all images, zooming in, and zooming out! 
                 *    
                private void ShowAllClick(object sender, RoutedEventArgs e) 
                { 
                        this.msi.ViewportOrigin = new Point(0, 0); 
                        this.msi.ViewportWidth = 1; 
                        ZoomFactor = 1; 
                } 
 
                private void zoomInClick(object sender, RoutedEventArgs e) 
                { 
                        Zoom(1.2, new Point(this.ActualWidth / 2, this.ActualHeight / 2)); 
                } 
 
                private void zoomOutClick(object sender, RoutedEventArgs e) 
                { 
                        Zoom(.8, new Point(this.ActualWidth / 2, this.ActualHeight / 2)); 
                } 
                 * */ 
        } 
}