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Silverlight 4 Default Support

For several months, I have successfully used the example David Justices default button in my SL 3 application. This approach is based on an attached property.

After upgrading to SL4, this approach no longer works, and I get a XAML exception:

Unknown parser error: scanner 2148474880

Has anyone successfully used this (or any other) default button attached by default in SL4?

Is there any other way to achieve the default button behavior in SL4 with the new classes available?

Thanks Mark

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5 answers

, ( Enter):

    public static DependencyProperty ButtonKeyProperty = DependencyProperty.RegisterAttached(
         "ButtonKey",
         typeof(Key),
         typeof(Defaults),
         new PropertyMetadata(Key.Enter, ButtonChanged));

    public static void SetButtonKey(DependencyObject dependencyObj, Key key)
    {
        dependencyObj.SetValue(ButtonKeyProperty, key);
    }

    public static Key GetButtonKey(DependencyObject dependencyObj)
    {
        return (Key)dependencyObj.GetValue(ButtonKeyProperty);
    }

, :

    Key key = GetButtonKey(dependencyObj);
    if (button.IsEnabled && keyEvent.Key == key)
        ...

, , , Escape , ( , ):

    ... UI:Defaults.Button="{Binding ElementName=myButton}" UI:Defaults.ButtonKey="Escape" ...
+2

, backing ( MVVM).... : peer.SetFocus();

Edit: XAML.

public static class DefaultButtonService
{
    public static DependencyProperty DefaultButtonProperty =
          DependencyProperty.RegisterAttached("DefaultButton",
                                              typeof(Button),
                                              typeof(DefaultButtonService),
                                              new PropertyMetadata(null, DefaultButtonChanged));

    private static void DefaultButtonChanged(DependencyObject d, DependencyPropertyChangedEventArgs e) {
        var uiElement = d as UIElement;
        var button = e.NewValue as Button;
        if (uiElement != null && button != null) {
            uiElement.KeyUp += (sender, arg) => {
                var peer = new ButtonAutomationPeer(button);

                if (arg.Key == Key.Enter) {
                    peer.SetFocus();
                    uiElement.Dispatcher.BeginInvoke((Action)delegate {

                        var invokeProv =
                            peer.GetPattern(PatternInterface.Invoke) as IInvokeProvider;
                        if (invokeProv != null)
                            invokeProv.Invoke();
                    });
                }
            };
        }

    }

    public static Button GetDefaultButton(UIElement obj) {
        return (Button)obj.GetValue(DefaultButtonProperty);
    }

    public static void SetDefaultButton(DependencyObject obj, Button button) {
        obj.SetValue(DefaultButtonProperty, button);
    }       
}

XAML:

<StackPanel>
    <TextBox DinnerConfig:DefaultButtonService.DefaultButton="{Binding ElementName=MyButton}"
                Text="Press Enter" />
    <Button x:Name="MyButton"
            Content="Click me" />
</StackPanel>
+8

, Silverlight 4 , , , , .

. Attached Properties.

SL 4 , , .

: http://www.cauldwell.net/patrick/blog/DefaultButtonSemanticsInSilverlightRevisited.aspx

Edit: David Justice, Silverlight 4. GetDefaultButton SetDefaultButton, DefaultButtonService. , . :

Edit2: XAML .

public class DefaultButtonService
    {
        public static DependencyProperty DefaultButtonProperty =
            DependencyProperty.RegisterAttached("DefaultButton",
                                                typeof(Button),
                                                typeof(DefaultButtonService),
                                                new PropertyMetadata(null, DefaultButtonChanged));

        private static void DefaultButtonChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            var uiElement = d as UIElement;
            var button = e.NewValue as Button;
            if (uiElement != null && button != null)
            {
                uiElement.KeyUp += (sender, arg) =>
                {
                    if (arg.Key == Key.Enter)
                    {
                        var peer = new ButtonAutomationPeer(button);
                        var invokeProv =
                            peer.GetPattern(PatternInterface.Invoke) as IInvokeProvider;
                        if (invokeProv != null)
                            invokeProv.Invoke();
                    }
                };
            }
        }

        public static DefaultButtonService GetDefaultButton(UIElement obj)
        {
            return (DefaultButtonService)obj.GetValue(DefaultButtonProperty);
        }

        public static void SetDefaultButton(DependencyObject obj, DefaultButtonService button)
        {
            obj.SetValue(DefaultButtonProperty, button);
        }        
    }

XAML:

<StackPanel>
    <TextBox DinnerConfig:DefaultButtonService.DefaultButton="{Binding ElementName=MyButton}"
                Text="Press Enter" />
    <Button x:Name="MyButton"
            Content="Click me" />
</StackPanel>
+3

- GetDefaultButton. Button, , :

    public static Button GetDefaultButton(UIElement obj)
    {
        return (Button)obj.GetValue(DefaultButtonProperty);
    }


    public static DefaultButtonService GetDefaultButton(UIElement obj)    
    {    
        return (DefaultButtonService)obj.GetValue(DefaultButtonProperty);    
    }

.

HTH - ,

0

:

Silverlight , , , .

1: ,

private void DoSharedRoutine(){ // do something }

2:

private void Login_Click(object sender, System.Windows.RoutedEventArgs e)
    {
        DoSharedRoutine();
    }

3: ,

private void MyGrid_KeyDown(object sender, System.Windows.Input.KeyEventArgs e)
     {
         if (e.Key == Key.Enter) DoSharedRoutine();
     }
0

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