在silverlight中使用OpenFileDialog浏览本地图片

 
     因为在Silverlight 2.0可以OpenFileDialog来访问本地文件，所以在Mike Taulty视频教程中也对这
个新特性进行了介绍，并做了一个简单的DEMO，如下所示（可以左右拖动调整图片宽度）:

 

     而实现这个功能的代码开发只有仅仅14行，简单得不能再简单了．

　　首先，我们先建立一个Silverlight Application,　然后将下面的xaml代码拷入到Page.xaml中：　　 

< Grid x:Name = " LayoutRoot "  Background = " Black "  ShowGridLines = " False "  Margin = " 8 " >
     < Grid.ColumnDefinitions >
         < ColumnDefinition Width = " 196 "   />
         < ColumnDefinition Width = " * "   />
     </ Grid.ColumnDefinitions >
     < Grid.RowDefinitions >
         < RowDefinition Height = " * "   />
         < RowDefinition Height = " 48 "   />
     </ Grid.RowDefinitions >
     < ListBox  x:Name = " myList "  HorizontalAlignment = " Stretch "  VerticalAlignment = " Stretch "
          ItemsSource = " {Binding} "
          Grid.Row = " 0 "
          Grid.Column = " 0 "
          Grid.RowSpan = " 2 "
          SelectionChanged = " OnSelectionChanged "   >
         < ListBox.ItemTemplate >
             < DataTemplate >
                 < TextBlock Text = " {Binding Name} "   />
         </ DataTemplate >
         </ ListBox.ItemTemplate >
     </ ListBox >
    
     < GridSplitter Width = " 1 "  HorizontalAlignment = " Left "  VerticalAlignment = " Stretch "  Grid.Column = " 1 "   />
    
     < Image  x:Name = " myImage "  Grid.Column = " 1 "   />
     < Button Grid.Row = " 1 "
      Grid.Column = " 1 "
      Content = " 选择图片 "
      Margin = " 8 "  Click = " OnClick "  FontSize = " 16 "   />
   
</ Grid >

相应Page.xaml.cs文件的代码如下：

public   partial   class  Page : UserControl
{
     public  Page()
    {
        InitializeComponent();
    }

   // 将选择图片按钮单击事件
     void  OnClick( object  sender, EventArgs args)
    {
        OpenFileDialog openFileDialog  =   new  OpenFileDialog()
        {
            Filter  =   " Jpeg Files (*.jpg)|*.jpg|All Files(*.*)|*.* " ,
            EnableMultipleSelection  =   true
        };

         if  (openFileDialog.ShowDialog()  ==  DialogResult.OK)
        {
// 向ListBox控件加载图片列表数据
            myList.DataContext  =  openFileDialog.SelectedFiles;
        }
    }



     private   void  OnSelectionChanged( object  sender, SelectionChangedEventArgs e)
    {
         if  ((e.AddedItems  !=   null )  &&  (e.AddedItems.Count  >   0 ))
        {
             // 获取选取的图片信息
            FileDialogFileInfo fi  =  e.AddedItems[ 0 ]  as  FileDialogFileInfo;

             if  (fi  !=   null )
            {
                 using  (Stream stream  =  fi.OpenRead())
                {　　
   // 获取图片流信息并完成与Image控件的绑定
                    BitmapImage image  =   new  BitmapImage();
                    image.SetSource(stream);
                    myImage.Source  =  image;
                    myImage.Visibility  =  Visibility.Visible;
                    stream.Close();
                }
            }
        }
    }
}

    代码很简单，大家看一下注释就可以了，总体感觉又回到了在学校时用delphi开发图片游览器的时候了:)

    源码下载链接请　点击这里．

    有兴趣的朋友不妨在这个DEMO上再开发新的功能，如上传，图片格式转换什么的,　相信会有所收获的:)