how to generate qr code in c# windows application LAYOUT CONTROLS: INCLUDING THE NEW SILVERLIGHT 4 CONTROLS in C#

Generation QR Code 2d barcode in C# LAYOUT CONTROLS: INCLUDING THE NEW SILVERLIGHT 4 CONTROLS

StackPanel; give it a foreground color of white. Do this again so you have two TextBlocks, as I have in Figure 4-29.

4. Now double-click the first TextBlock to edit the Text and type in Silverlight Rocks! 5. Double-click the second TextBlock to edit the Text and paste in

Silverlight! (the Arabic equivalent of Silverlight Rocks!) Your StackPanel should look like what I have in Figure 4-30.

Figure 4-30. Your StackPanel should now look like this. Although this looks quite cool, it is quite incorrect because Arabic is written and read from right to left not left to right, as English is. We can correct this by giving the second TextBlock a FlowDirection of RightToLeft. See my code: <TextBlock FlowDirection="RightToLeft" TextWrapping="Wrap" Text= " Silveright!" Foreground="White"/>

You should have what I have in Figure 4-31.

Figure 4-31. Your second TextBlock is now able to be read from right to left and is correct for the Arabic language. As I mention earlier, this property applies to content controls as well as Text controls. For example, if we were to put a FlowDirection property of RightToLeft on the parent StackPanel, all of its children would inherit that property and thus all be aligned right. Try adding that property to the StackPanel, and you should see what I have in Figure 4-32.

Figure 4-32. Content Controls such as StackPanel can also have a FlowDirection property. And children of the control will inherit this property.

Data Binding is an easy way for Silverlight controls to bind to data. That data can be either a set of predefined data or data of another object. For example, if you had a String property named Foo with a value of Silverlight Rocks you could, in XAML Data Bind a TextBlock s Text value to the value of Foo, and the TextBlock would read Silverlight Rocks. Further, if the TextBlock had a Binding mode set to TwoWay, then if the TextBlock s value were to change, Foo would change as well. Silverlight 4 has improved Data Binding in a few ways:

Now in Silverlight 4 you can bind to properties on a DependencyObject and not just on FrameworkElements. What, you ask is a DependencyObject A DependencyObject is the base class of several important Silverlight classes such as UIElements, Styles, Resource Dictionaries, and Transformations. So now you can bind a Framework Element s X position in a TranslateTransform transformation to the value of a Slider. This will allow you to move the Slider and change the position of the FrameworkElement. Prior to Silverlight 4 this was not possible.

If a Silverlight entity implements the IDataErrorInfo interface and then is involved in a binding operation, it validates the bound properties and can then notify the UI of any binding errors and if the NotifyOnValidationError property is set to True, any error messages can be displayed. Basically this gives developers a way to know when binding errors have occurred via asynchronous server-side validation errors.

Silverlight 4 now allows you to tell the bound object how to display its data. For example, say you are binding to a Date object and want a particular format for that date, now you can simply set your binding expression to this: <TextBox Text="{Binding Path=PublishedDate, Mode=OneWay, StringFormat='MM-ddyyyy'}"/> This will format your date to this format: 01-24-10 and override the default format of the Date object. Prior to Silverlight 4 the object would have to be manipulated in code-behind prior to populating the TextBlock. You can now set a FallbackValue for a binding expression. If the binding fails for any reason, what will be displayed is the FallbackValue. Example: <TextBox Text="{Binding Path=SomeBindingValue, Mode=TwoWay, FallbackValue=N/A}" /> TargetNullValue allows you to set a value if the binding expression encounters a null value. Example: