Tonight I’m doing a talk at “Silverlight developers in Denmark” (SLDEV). The talk will focus on the new features in Silverlight 5 and I promise I will bring lots of demos.
You can download the slides here.
Tag Archives: Silverlight 5 beta
Silverlight 5 – Default file name in SaveFileDialog
25 MayA long requested feature coming with Silverlight 5 is the opportunity to set the default file name in the SaveFileDialog. In previous versions of Silverlight this missing feature have resulted in some bad user experiences, but finally it is here and it is easy to use.
To demonstrate it I have create a demo writing a text file to the computer allowing the user to set the default file name from the very beginning.
When the user clicks the Save-button the SaveFileDialog is shown and the user can save the file locally on the computer. The text from the TextBox is parsed to the SaveFileDialog as the default file name.
In the code I have set the Filter, the DefaultExt and the DefaultFileName on my SaveFileDialog instance. This provide an optimal experience for my user when saving files.
You can download the demo here.
Silverlight 5 – Debugging bindings in XAML
24 MayOne of the cool new tool features in Silverlight 5 is the XAML debugging features. It is limited to debugging bindings in XAML but that is an extremely useful feature.
I have created a demo showing the few steps needed to debug bindings in XAML. The demo consist of a TextBox containing a number a Button to refresh the number. The number is a random number.
The Text property of the TextBox binds to a property called “Number”. It is a Dependency Property defined in my code-behind. To make the binding work I have set the DataContext of the page to its self.
Whenever the Number property is updated it will automatically update the Text value on the TextBox.
As simple as it is I can spend hours looking for errors if I e.g. misspell the property that we use to bind to. Before Silverlight 5 I would get a hint in the Output window if I had a BindingExpression exception. In Silverlight 5 I can add a breakpoint to the binding directly in the XAML.
Debugging the XAML above I get an exception with a BindingExpression path error and enables me to easily identify the error.
You can download the sample here.
Silverlight 5 – Custom Markup Extensions
20 AprA Markup Extension is a class that decides at runtime how to set a property’s value. Markup extensions allow code to be run at XAML parse time for both properties and event handlers.
In Silverlight 4 we got some different Markup Extensions:
- Binding
Text=”{Binding Path=FirstName, Mode=TwoWay}” - StaticResource
Foreground=”{StaticResource BlueSolidColor}” - TemplateBinding
VerticalAlignment=”{TemplateBinding VerticalContentAlignment}” - NullExtension
Background={x:Null} - RelativeSource
DataContext="{Binding RelativeSource={RelativeSource TemplatedParent}}"
With Silverlight 5 we get Custom Markup Extensions allowing us to write more specific and complex Markup Extensions.
Jeff Prosise’s have written a good sample here and Jeremy Likness have written about getting creating a custom markup extension that uses MEF to satisfy imports on object instances declared in XAML here.
Silverlight 5 – Elevated Trust In-Browser
20 AprIn Silverlight 5 it is possible to enable applications to run with elevated permissions in-browser.
The code snippet below will open Notepad.exe using the AutomationFactory in Silverlight. Using the AutomationFactory requires elevated permissions.
To run the snippet in Silverlight 4 the application must run with elevated permissions and in out-of-browser. In Silverlight 5 it is possible to run the snippet in-browser and with elevated permissions.
There are some requirements that need to be fulfilled to be able to run with elevated permissions in-browser. The XAP file needs to be signed with a certificate present in the Trusted Publishers Certificate store. Furthermore it is necessary to add a registry setting:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Silverlight\
Add the following DWORD key "AllowElevatedTrustAppsInBrowser" with 0x00000001.
In order to make development a bit easier running using localhost (or 127.0.0.1) won’t require signing the XAP file or adding the registry setting.
You can download the demo here.
Silverlight 5 – ClickCount
13 AprSilverlight 5 enables support for multi-click input on left and right mouse button making it easier to implement features like double click. ClickCount is available on MouseButtonEventArgs.
Silverlight 5 – Multiple Windows Support
13 AprSilverlight 5 supports the ability to open multiple top level windows. It is required that the application run with elevated permissions.
Closing the main application window will cause all windows to close.
I have added a small demo here.
