barcodelib.barcode.asp.net.dll download Figure 3-7. The DockPanel with inner nesting of controls with LastChildFill set to false in VB.NET

Printing Denso QR Bar Code in VB.NET Figure 3-7. The DockPanel with inner nesting of controls with LastChildFill set to false

By preventing the last child from filling the space, it s possible to place more content around the edges of the container. The unfortunate consequence of this is that now the leftover space won t automatically be used by the last child added. One way to fill up the remaining space is by setting the width/height on the last child so that it fills up the space. Another technique is to nest a DockPanel within a DockPanel, giving you the ability to create the same interface as shown in Figure 3-7 without losing the fill behavior of the last child.

The WrapPanel is the other layout container available as part of the Silverlight Toolkit. As you did in the DockPanel section, add a reference of Systems.Windows.Controls.Toolkit.dll, delivered as part of the Silverlight toolkit, to the project and add a reference of this namespace to the UserControl within the XAML file. Its behavior is similar to the StackPanel in that you can automatically place content adjacent to each other (left to right or top to bottom), but it adds the behavior of wrapping content to the next row or column of an invisible grid when the content reaches the end of its available space. Added images under the scope of the WrapPanel shown in Figure 3-8 and Figure 3-9 represent the behavior of the WrapPanel with the horizontal and vertical orientation.

To develop the example shown in Figure 3-8, create a res folder under the project and then add the sample images, available in your machine, to the newly created res folder of the project and rename them 1.jpg to 5.jpg. Add the following code snippet to the user control to show the added images within the scope of the horizontally-oriented WrapPanel control, as shown here. <StackPanel> <TextBlock Text="Horizontally Oriented WrapPanel Example" Margin="5" FontWeight="Bold"/> <c:WrapPanel Width="500" Height="250" Orientation="Horizontal"> <Image Width="150" Height="100" Margin="2" Source="res/1.jpg"/> <Image Width="150" Height="100" Margin="2" Source="res/2.jpg"/> <Image Width="150" Height="100" Margin="2" Source="res/3.jpg"/> <Image Width="150" Height="100" Margin="2" Source="res/4.jpg"/> <Image Width="150" Height="100" Margin="2" Source="res/5.jpg"/> </c:WrapPanel> </StackPanel> Note that we have added the WrapPanel control within the StackPanel to display the title of the sample application. The WrapPanel exposes three new properties, as shown in Table 3-9, all of which are also dependency properties. The Orientation property controls whether child content is stacked horizontally (wrapping to the next row) or vertically (wrapping to the next column). In the preceding code snippet, if you change the Orientation property of the WrapPanel to Vertical, increase the value of the Height property, and change the TextBlock s Text properly, you will get an outcome similar to Figure 3.9. Table 3-10. Key Properties of the System.Windows.Controls.WrapPanel Class

Specifies the height of each item. Can be set to Auto or a qualified value using the suffix px for device independent pixels, in for inches, cm for centimeters, or pt for points. The default is pixels. Specifies the width of each item. Can be set to Auto (default value) or a qualified value using a suffix.

Orientation Specifies whether child content is stacked horizontally (wrapping to the next row) or vertically (wrapping to the next column). Can be set to Horizontal (default value) or Vertical.

The TabControl is used to host multiple items sharing the same space on the screen, with each page accessible via a tab. Table 3-11 describes its key properties.

Specifies the content of the currently active TabItem. Gets/sets the index of the currently active TabItem, or -1 if no TabItem is active. Specifies the currently active TabItem, or null if no TabItem is active. Gets/sets how TabItem headers align relative to the TabItem content and thus defines the place where Tabs are displayed within the TabControl. The Dock enumeration has four possible values specifying the behavior of the TabControl. They are Left, Top (default), Right, and Bottom.