Encapsulates a Silverlight application.
Assembly: System.Windows (in System.Windows.dll)
Thetype exposes the following members.
|ApplicationLifetimeObjects||Gets the application extension services that have been registered for this application.|
|Current||Gets the object for the current application.|
|HasElevatedPermissions||Gets a value that indicates whether the application is running with elevated permissions.|
|Host||Gets various details about the Silverlight application's host.|
|InstallState||Gets the current out-of-browser installation state of the application.|
|IsRunningOutOfBrowser||Gets a value that indicates whether the application was launched from the out-of-browser state.|
|MainWindow||Gets the out-of-browser application window.|
|Resources||Gets a collection of application-scoped resources, such as styles, templates, and brushes.|
|RootVisual||Gets or sets the main application UI.|
|Windows||Gets a collection of the Window instances that have been created.|
|CheckAndDownloadUpdateAsync||Launches an asynchronous process to check for and download an updated version of the application.|
|Equals(Object)||Determines whether the specified Object is equal to the current Object. (Inherited from Object.)|
|Finalize||Allows an object to try to free resources and perform other cleanup operations before the Object is reclaimed by garbage collection. (Inherited from Object.)|
|GetHashCode||Serves as a hash function for a particular type. (Inherited from Object.)|
|GetResourceStream(Uri)||Returns a resource file from a location in the application package.|
|GetResourceStream(StreamResourceInfo, Uri)||Returns a resource file from a location in the specified zip package.|
|GetType||Gets the Type of the current instance. (Inherited from Object.)|
|Install||Attempts to install the application so that it can run outside the browser.|
|LoadComponent||Loads a XAML file that is located at the specified Uniform Resource Identifier (URI) and converts it to an instance of the object that is specified by the root element of the XAML file.|
|MemberwiseClone||Creates a shallow copy of the current Object. (Inherited from Object.)|
|ToString||Returns a string that represents the current object. (Inherited from Object.)|
|CheckAndDownloadUpdateCompleted||Occurs when the application has finished checking for updates in response to a CheckAndDownloadUpdateAsync method call.|
|Exit||Occurs just before an application shuts down and cannot be canceled.|
|InstallStateChanged||Occurs when the InstallState property value changes.|
|Startup||Occurs when an application is started.|
|UnhandledException||Occurs when an exception that is raised by Silverlight is not handled.|
is a class that encapsulates a Silverlight application and provides the following services:
Application Entry Point
Unhandled Exception Detection
The entry point in a Silverlight application is the class in your application assembly that derives from . This class is known as the application class. When the Silverlight plug-in starts, Silverlight uses metadata in the application package to instantiate the application class. At this point, the application's lifetime starts. The lifetime of an application occurs in the following order:
Application Shutting Down (initiated by user)
By handling the Startup event, you can retrieve and process initialization parameters from the InitParams property of the StartupEventArgs object that is passed to the Startup event handler. Initialization parameters are configured by using the initParams property of the HTML object element that is used to configure and instantiate the Silverlight plug-in.
During startup, you can also specify the main application UI to show by setting the RootVisual property.
Once an application is running, the object and its state can be accessed from the static Current property. The singleton pattern ensures that state managed by , including shared resources (Resources) and custom properties, is available from a single, application-scoped location.
XAML Usage Notes for the Application class
In practical XAML usage, is almost always the root element of the App.xaml file and therefore a practical usage would include the client and XAML xmlns values, as well as an x:Class value for the code-behind that initiates the root visual, as shown in the following XAML fragment.
<Application xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" x:Class="namespace.class"... > ... </Application>
Technically the XAML usage for any member of the class that supports XAML applies both to the class and also to any subclass that does not specifically disable XAML usage by shadowing members or changing the access level of its constructors. However, the XAML usage for members shows the literal rather than the placeholder application because subclassing is not necessary for most Silverlight application model scenarios, and the XAML usage shows the most common usage patterns whenever possible.
The following code example demonstrates how to use this class to merge the XAML and code-behind portions of a Page class. This code is similar to the InitializeComponent method that Visual Studio generates for the same purpose.
Visual Studio generates the InitializeComponent method when a XAML file has a build action of Page. To load a XAML file using the following example code, set its build action to Resource.
Private LayoutRoot As System.Windows.Controls.Grid Public Sub New() System.Windows.Application.LoadComponent(Me, New System.Uri( _ "/SilverlightApplication1;component/Page.xaml", _ System.UriKind.Relative)) Me.LayoutRoot = CType(Me.FindName("LayoutRoot"), _ System.Windows.Controls.Grid) End Sub
For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.