Data Validation in Silverlight 3

 1: public class User

 2: {

 3:     public string Name

 4:     {

 5:         get { return name; }

 6:         set

 7:         {

 8:             if ( string.IsNullOrEmpty( value ) )

 9:             {

 10:                 throw new Exception( "Please set a value" );

 11:             }

 12:  

 13:             name = value;

 14:         }

 15:     }

 16:  

 17:     public bool Gender { ... }

 18:  

 19:     public string LikesSilverlight { ... }

 20:  

 21:     public string Attended { ... }

 22:  

 23:     public bool AcceptTerms { ... }

 24:  

 25:     private string name;

 26:     private bool gender;

 27:     private string likesSilverlight;

 28:     private string attended;

 29:     private bool acceptTerms;

 30: }

 1: <StackPanel>

 2:     <StackPanel.DataContext>

 3:         <local:User />

 4:     </StackPanel.DataContext>

 5:     <TextBlock Text="Registration Form" FontSize="16"/>

 6:     <TextBlock Text="Name" />

 7:     <TextBox Text="{Binding Name, Mode=TwoWay, ValidatesOnExceptions=True}"/>

 8:     <TextBlock Text="Gender" />

 9:     <StackPanel Orientation="Horizontal">

 10:         <RadioButton GroupName="Gender" Content="Male" IsChecked="True" />

 11:         <RadioButton GroupName="Gender" Content="Female" 

 12:             IsChecked="{Binding Gender, Mode=TwoWay, ValidatesOnExceptions=True}" />

 13:     </StackPanel>

 14:     <TextBlock Text="I Like Silverlight" />

 15:     <ComboBox x:Name="LikesSilverlightCombo" 

 16:         SelectedItem="{Binding LikesSilverlight, Mode=TwoWay, 
 17:                         ValidatesOnExceptions=True, UpdateSourceTrigger=Explicit}"

>

 18:         <sys:String>Yes</sys:String>

 19:         <sys:String>No</sys:String>

 20:     </ComboBox>

 21:     <TextBlock Text="I've attended" />

 22:     <ListBox SelectionMode="Extended"

 23:         SelectedItem="{Binding Attended, Mode=TwoWay, ValidatesOnExceptions=True}">

 24:         <sys:String>None</sys:String>

 25:         <sys:String>MIX 07</sys:String>

 26:         <sys:String>MIX 08</sys:String>

 27:         <sys:String>MIX 09</sys:String>

 28:     </ListBox>

 29:     <CheckBox x:Name="AcceptTermsCheckBox" Content="Accept Terms" 

 30:         IsChecked="{Binding AcceptTerms, Mode=TwoWay, ValidatesOnExceptions=True}" />

 31:     <Button Content="Register" Click="Validate" 

 32:         IsEnabled="{Binding IsChecked, ElementName=AcceptTermsCheckBox}" />

 33: </StackPanel>

BindingExpression be = this.LikesSilverlightCombo.GetBindingExpression( ComboBox.SelectedItemProperty );

be.UpdateSource();