Five Minute Silverlight 4 Aides-Memoire #7 – IDataErrorInfo

The XAML:

DATA INPUT

1. <Grid x:Name="LayoutRoot">
2.   <Grid.Resources>
3.     <local:Person x:Key="NewJoiner" Age="49" Forename="Fred" Surname="Flintstone" />
4.   </Grid.Resources>
5.   <Grid DataContext="{StaticResource NewJoiner}">
6.     <Grid.ColumnDefinitions>
7.       <columndefinition Width="1*" />
8.       <columndefinition Width="5*" />
9.     </Grid.ColumnDefinitions>
10.     <Grid.RowDefinitions>
11.       <rowdefinition Height="50" />
12.       <rowdefinition Height="50" />
13.       <rowdefinition Height="50" />
14.     </Grid.RowDefinitions>
15.     <Grid.Resources>
16.       <Style TargetType="TextBlock">
17.         <setter Property="Margin" Value="10" />
18.         <setter Property="HorizontalAlignment" Value="Right" />
19.         <setter Property="VerticalAlignment" Value="Center" />
20.       </Style>
21.       <Style TargetType="TextBox">
22.         <setter Property="Margin" Value="10" />
23.         <setter Property="Width" Value="154" />
24.         <setter Property="HorizontalAlignment" Value="Left" />
25.         <setter Property="VerticalAlignment" Value="Center" />
26.       </Style>
27.     </Grid.Resources>
28.     <TextBlock Text="First Name" Grid.Row="0" Grid.Column="0" />
29.     <TextBlock Text="Last Name" Grid.Row="1" Grid.Column="0" />
30.     <TextBlock Text="Age" Grid.Row="2" Grid.Column="0" />
31.     <textbox x:Name="Forename" Grid.Row="0" Grid.Column="1" Text="{Binding Forename, Mode=TwoWay, ValidatesOnDataErrors=True}" />
32.     <textbox x:Name="Surname" Grid.Row="1" Grid.Column="1" Text="{Binding Surname, Mode=TwoWay, ValidatesOnDataErrors=True}" />
33.     <textbox x:Name="Age" Grid.Row="2" Grid.Column="1" Text="{Binding Age, Mode=TwoWay, ValidatesOnDataErrors=True}" />
34.   </Grid>
35. </Grid>

The code:

IMPLEMENTATION

1. public class Person : IDataErrorInfo
2. {
3.     public string Forename { get; set; }
4.     public string Surname { get; set; }
5.     public int Age { get; set; }
6.     public string Error { get { return null; } }
7.  
8.     public string this[string columnName]
9.     {
10.         get
11.         {
12.             string error = null;
13.             switch (columnName)
14.             {
15.                 case "Forename":
16.                     if (string.IsNullOrEmpty(Forename))
17.                         error = "Forename required";
18.                     break;
19.                 case "Surname":
20.                     if (string.IsNullOrEmpty(this.Surname))
21.                         error = "Surname required";
22.                     break;
23.                 case "Age":
24.                     if (this.Age < 0 || this.Age > 130)
25.                         error = "Invalid Age";
26.                     break;
27.             }
28.             return error;
29.         }
30.     }
31. }

The result:

Five Minute Silverlight 4 Aides-Memoire #6 – Right Mouse Event Support

<Popup x:Name="PopupMenu" IsOpen="False">
    <ListBox x:Name="MenuItems">
        <ListBoxItem Content="Item 1" />
        <ListBoxItem Content="Item 2" />
        <ListBoxItem Content="Item 3" />
        <ListBoxItem Content="Item 4" />
    </ListBox>
</Popup>

public MainPage()
{
    InitializeComponent();
    MouseRightButtonDown += (s, e) => e.Handled = true;
    MouseRightButtonUp += MainPage_MouseRightButtonUp;
    MenuItems.MouseLeftButtonUp += MenuItems_MouseLeftButtonUp;
}

void MainPage_MouseRightButtonUp(object sender, System.Windows.Input.MouseButtonEventArgs e)
{
    this.PopupMenu.HorizontalOffset = e.GetPosition(this).X;
    this.PopupMenu.VerticalOffset = e.GetPosition(this).Y;
    this.PopupMenu.IsOpen = true;
}

void MenuItems_MouseLeftButtonUp(object sender, System.Windows.Input.MouseButtonEventArgs e)
{
    PopupMenu.IsOpen = false;
    System.Diagnostics.Debug.WriteLine(((sender as ListBox).SelectedItem as ListBoxItem).Content);
}

Five Minute Silverlight 4 Aides-Memoire #5 – Rich Text Area Control

<RichTextArea x:Name="Editor">
    <RichTextArea.Blocks>
        <Paragraph>
            <Run Foreground="Blue" Text="This is "/>
            <Run Foreground="Red" FontWeight="Bold" Text="some sample " />
            <Run FontStyle="Italic" Text="text" />
        </Paragraph>
        <Paragraph>
            <Run Text="Here is "/>
            <Run TextDecorations="Underline" Text="some more" />
        </Paragraph>
    </RichTextArea.Blocks>
</RichTextArea>

void UnderlineSelection_Click(object sender, RoutedEventArgs e)
{
    var currentValue = this.Editor.Selection.GetPropertyValue(TextElement.TextDecorationsProperty);
    TextDecorationCollection setValue = TextDecorations.Underline;
    if (currentValue != DependencyProperty.UnsetValue)
        setValue = (TextDecorationCollection)currentValue == setValue ? null : setValue;
    this.Editor.Selection.SetPropertyValue(TextElement.TextDecorationsProperty, setValue);
}

void ItalicSelection_Click(object sender, RoutedEventArgs e)
{
    var currentValue = this.Editor.Selection.GetPropertyValue(TextElement.FontStyleProperty);
    FontStyle setValue = FontStyles.Italic;
    FontStyle defaultValue = FontStyles.Normal;
    if (currentValue != DependencyProperty.UnsetValue)
        setValue = (FontStyle)currentValue == setValue ? defaultValue : setValue;
    this.Editor.Selection.SetPropertyValue(TextElement.FontStyleProperty, setValue);
}

void BoldSelection_Click(object sender, RoutedEventArgs e)
{
    var currentValue = this.Editor.Selection.GetPropertyValue(TextElement.FontWeightProperty);
    FontWeight setValue = FontWeights.Bold;
    FontWeight defaultValue = FontWeights.Normal;
    if (currentValue != DependencyProperty.UnsetValue)
        setValue = (FontWeight)currentValue == setValue ? defaultValue : setValue;
    this.Editor.Selection.SetPropertyValue(TextElement.FontWeightProperty, setValue);
}

Five Minute Silverlight 4 Aides-Memoire #4 – Clipboard Access

private void PopButton_Click(object sender, RoutedEventArgs e)
{
    var newPara = new Paragraph();

    newPara.Inlines.Add(new Run { Text = Clipboard.GetText() });

    this.rightRichTextArea.Blocks.Add(newPara);
}

private void PushButton_Click(object sender, RoutedEventArgs e)
{
    Clipboard.SetText(this.leftRichTextArea.Selection.Text);
}

Five Minute Silverlight 4 Aides-Memoire #3 – WebCam/Microphone Device Support

<UserControl.Resources>
    <Style x:Key="ListBoxStyle" TargetType="ListBox">
        <Setter Property="ItemTemplate">
            <Setter.Value>
                <DataTemplate>
                    <Image Margin="5" Source="{Binding}" Stretch="UniformToFill" Height="80" VerticalAlignment="Center"/>
                </DataTemplate>
            </Setter.Value>
        </Setter>
        <Setter Property="ItemsPanel">
            <Setter.Value>
                <ItemsPanelTemplate>
                    <StackPanel Orientation="Horizontal" VerticalAlignment="Center" HorizontalAlignment="Center"/>
                </ItemsPanelTemplate>
            </Setter.Value>
        </Setter>
    </Style>
</UserControl.Resources>

<StackPanel Grid.Row="2" Grid.Column="0">
    <Button Content="Start WebCam" Click="StartWebCam_Click" Height="30" />
    <Button Content="Snapshot" Click="Snapshot_Click" Height="30" />
</StackPanel>
<Rectangle Grid.Row="0" Stretch="Fill" Grid.Column="1" x:Name="CapturedImage" />
<ListBox Grid.Row="1" Margin="10" Grid.RowSpan="2" Grid.Column="1" x:Name="Snapshots" Style="{StaticResource ListBoxStyle}"/>

private void StartWebCam_Click(object sender, RoutedEventArgs e)
{
    if (!CaptureDeviceConfiguration.AllowedDeviceAccess & !CaptureDeviceConfiguration.RequestDeviceAccess())
        return;

    VideoBrush videoBrush = new VideoBrush();
    videoBrush.SetSource(captureSource);
    CapturedImage.Fill = videoBrush;
    this.Snapshots.ItemsSource = snaps;
    captureSource.Start();
}

private void Snapshot_Click(object sender, RoutedEventArgs e)
{
    captureSource.AsyncCaptureImage((image) => { snaps.Add(image); });
}

Five Minute Silverlight 4 Aides-Memoire #2 – Printing

private void Print_Click(object sender, RoutedEventArgs e)
{
    PrintDocument printDoc = new PrintDocument();

    // Name that will show in the spooler...
    printDoc.DocumentName = "Directory Tree";
    printDoc.PrintPage += new EventHandler<PrintPageEventArgs>(printDoc_PrintPage);
    printDoc.Print();
}

private void printDoc_PrintPage(object sender, PrintPageEventArgs e)
{
    // Needs a UIElement (visual tree)
    e.PageVisual = DirectoriesTreeView;

    // Setting true will ensure PrintPage is called again for subsequent pages
    e.HasMorePages = false;
}