Using a Pan Window and Interactive Modes in Silverlight

SilverlightTutorials

Take the following steps to start a project and to add some code that will demonstrate the various interactive modes of the LEADTOOLS Silverlight Control and the Pan Viewer:

1. Start Visual Studio .NET.
2. Start with the project that you created in Loading and displaying an image in Silverlight.

3. Open the Page.xaml file and copy the below XAML code into the editor:

   [XAML]

   <UserControl x:Class="Load_And_Display.MainPage" 
     xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"  
     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"  
     xmlns:Leadtools_Windows_Controls="clr-namespace:Leadtools.Windows.Controls;assembly=Leadtools.Windows.Controls" 
     Width="800" Height="600"> 
     <Grid x:Name="LayoutRoot" Background="White"> 
       <Grid.ColumnDefinitions>        
           <ColumnDefinition Width="5*"/> 
           <ColumnDefinition Width="2*"/> 
       </Grid.ColumnDefinitions> 
                         
       <ScrollViewer VerticalScrollBarVisibility="Disabled" HorizontalScrollBarVisibility="Disabled" Grid.Column="0"> 
           <StackPanel Orientation="Vertical" > 
               <Button Name="myButton" Content="Load" FontSize="30" Click="Button_Click" Height="40"></Button> 
               <Leadtools_Windows_Controls:RasterImageViewer x:Name="viewerControl" SizeMode="Normal" Height="550"></Leadtools_Windows_Controls:RasterImageViewer>  
           </StackPanel> 
       </ScrollViewer> 
                         
       <ScrollViewer VerticalScrollBarVisibility="Disabled" HorizontalScrollBarVisibility="Disabled" Grid.Column="1"> 
           <StackPanel Orientation="Vertical" > 
               <TextBlock Text="Pan Window :"/> 
               <Leadtools_Windows_Controls:ImagePanViewer x:Name="_imagePanViewer" Width="150" Height="150" HorizontalAlignment="Left"></Leadtools_Windows_Controls:ImagePanViewer> 
               <TextBlock Text="Interactive Mode :"/> 
               <ComboBox Name="_cmbInteractiveMode" SelectedIndex="0" Width="200" HorizontalAlignment="Left" SelectionChanged="ComboBox_SelectionChanged"> 
                   <ComboBoxItem Content="None"/> 
                   <ComboBoxItem Content="Pan"/> 
                   <ComboBoxItem Content="Center At"/> 
                   <ComboBoxItem Content="Zoom To"/> 
                   <ComboBoxItem Content="Scale"/> 
                   <ComboBoxItem Content="Magnify Glass"/> 
               </ComboBox> 
           </StackPanel> 
       </ScrollViewer>     
     </Grid> 
   </UserControl> 

4. Switch to Page.xaml code view (right-click Page.xaml in the solution explorer then select View Code) and add the following class function:

   C#

   VB
   Private Sub ComboBox_SelectionChanged(ByVal sender As Object, ByVal e As SelectionChangedEventArgs) 
     If _cmbInteractiveMode Is Nothing OrElse _cmbInteractiveMode.SelectedItem Is Nothing Then 
        Return 
     End If 
                    
     Dim item As String = (CType(IIf(TypeOf _cmbInteractiveMode.SelectedItem Is ComboBoxItem, _cmbInteractiveMode.SelectedItem, Nothing), ComboBoxItem)).Content.ToString() 
                    
     Select Case item 
        Case "Pan" 
           viewerControl.InteractiveMode = Leadtools.Windows.Controls.InteractiveMode.Pan 
                    
        Case "Center At" 
           viewerControl.InteractiveMode = Leadtools.Windows.Controls.InteractiveMode.CenterAt 
                    
        Case "Magnify Glass" 
           viewerControl.InteractiveMode = Leadtools.Windows.Controls.InteractiveMode.MagnifyGlass 
                    
        Case "Scale" 
           viewerControl.InteractiveMode = Leadtools.Windows.Controls.InteractiveMode.Scale 
                    
        Case "Zoom To" 
           viewerControl.InteractiveMode = Leadtools.Windows.Controls.InteractiveMode.ZoomTo 
                    
        Case Else 
           viewerControl.InteractiveMode = Leadtools.Windows.Controls.InteractiveMode.None 
     End Select 
   End Sub 
                     
        

   private void ComboBox_SelectionChanged(object sender, SelectionChangedEventArgs e) 
   { 
     if (_cmbInteractiveMode == null ||   _cmbInteractiveMode.SelectedItem == null) 
        return; 
                    
     string item = (_cmbInteractiveMode.SelectedItem as ComboBoxItem).Content.ToString(); 
                    
     switch (item) 
     { 
        case "Pan": 
           viewerControl.InteractiveMode = Leadtools.Windows.Controls.InteractiveMode.Pan; 
           break; 
                    
        case "Center At": 
           viewerControl.InteractiveMode = Leadtools.Windows.Controls.InteractiveMode.CenterAt; 
           break; 
                    
        case "Magnify Glass": 
           viewerControl.InteractiveMode = Leadtools.Windows.Controls.InteractiveMode.MagnifyGlass; 
           break; 
                    
        case "Scale": 
           viewerControl.InteractiveMode = Leadtools.Windows.Controls.InteractiveMode.Scale; 
           break; 
                    
        case "Zoom To": 
           viewerControl.InteractiveMode = Leadtools.Windows.Controls.InteractiveMode.ZoomTo; 
           break; 
                    
        default: 
           viewerControl.InteractiveMode = Leadtools.Windows.Controls.InteractiveMode.None; 
           break; 
     } 
   } 
                     
        

5. Update the Button_Click event as shown below:

   C#

   VB
   Private Sub Button_Click(ByVal sender As Object, ByVal e As RoutedEventArgs) 
     Try   
        Dim ofd As OpenFileDialog = New OpenFileDialog() 
        If ofd.ShowDialog() = True Then 
           Dim fileStream As FileStream = ofd.File.OpenRead() 
           Try 
              Dim codecs As RasterCodecs = New RasterCodecs() 
              viewerControl.Image = codecs.Load(fileStream) 
              _imagePanViewer.Source = viewerControl 
           Finally 
              fileStream.Dispose() 
           End Try 
        End If 
     Catch ex As Exception 
        MessageBox.Show(ex.Message) 
     End Try 
   End Sub 
                     
        

   private void Button_Click(object sender, RoutedEventArgs e) 
   { 
     try 
     { 
        OpenFileDialog ofd = new OpenFileDialog(); 
        if (ofd.ShowDialog() == true) 
        { 
           using (FileStream fileStream = ofd.File.OpenRead()) 
           { 
              RasterCodecs codecs = new RasterCodecs(); 
              viewerControl.Image = codecs.Load(fileStream); 
              _imagePanViewer.Source = viewerControl; 
           } 
        } 
     } 
     catch (Exception ex) 
     { 
        MessageBox.Show(ex.Message); 
     } 
   } 
                     
        

6. Build, and Run the program to test it.

   Click the "Load" button, and select an image. NOTE: if you encounter an "Invalid File Format" or "Feature Not Supported" exception, please refer to the topic Invalid File Format/Feature Not Supported.