MSDN Magazine - November 2008 - (Page 32)

The Document property returns a reference to an object of the managed type System.Windows.Browser.HtmlDocument, which represents the DOM of the underlying page. The Document property is strongly typed and exposes to Silverlight applications most of the features available to script in a weakly typed manner. Properties include the list of cookies, the query string, the body of the document, and the reference to the root of the DOM. The object also features a Boolean IsReady property to signal whether the browser’s document has been fully loaded, which is paired with transposition of the DocumentReady event in the browser’s DOM. The HtmlDocument class also features methods such as Submit, AttachEvent, DetachEvent, GetElementById, and CreateElement. Figure 1 Properties of the Silverlight ASP.NET Server Control Property AutoUpgrade Description Indicates whether the Silverlight plug-in should automatically be upgraded. The default is false. The default type of the client JavaScript object to create and associate with the Silverlight plug-in. By default, it is Sys.UI.Silverlight.Control. Indicates whether to display the current frame rate in the hosting browser’s status bar. The default is true. Indicates whether to show the areas of the Silverlight plug-in that are being redrawn for each frame. The default is true. Indicates whether to allow the Silverlight application to access the page DOM. Defines an optional set of user-defined initialization parameters. Maximum number of frames to render per second for the Silverlight document. Minimum version of the plug-in that is required for the current application. The default is 1.0. Indicates the plug-in background color. HTML markup to render if the Silverlight plug-in is not installed. Indicates how the Silverlight plug-in fills the available space: none, zoom, or stretch. The default is none. The type of the client JavaScript object to create and associate with the Silverlight plug-in. The URL for the XAML source file or the Extensible Ajax Platform (XAP) source package to download. The URL of the splash screen document to render when the source document is loading. Indicates whether the Silverlight plug-in is rendered directly in the browser’s client area or within an aptly created window. The default is true. In addition, a couple of inherited methods—GetProperty and SetProperty—allow you to get and set attributes of the HTML elements from within managed code. Full browser information is available through the BrowserInformation property. Also, in this case, the property is of a managed type that wraps any user agent information that is available at the browser level. The following code snippet shows how to access user-agent data: string info = HtmlPage.BrowserInformation.UserAgent; The BrowserInformation object also exposes a Boolean property that indicates whether the browser supports cookies. The following code shows how to retrieve a reference to a DOM element using managed code: HtmlElement label1 = HtmlPage.Document.GetElementById("Label1"); label1.SetProperty("innerHTML", "Dino"); DefaultScriptType EnableFrameRateCounter The GetElementById method takes an ID string and attempts to locate a corresponding element in the underlying DOM. The object returned is of type HtmlElement—a managed type acting as the wrapper for a reference to an underlying browser object. HtmlElement features a set of properties that makes it look like an HTML element. It has methods such as AppendChild, RemoveChild, GetAttribute, RemoveAttribute, and SetAttribute. Properties are Id, Parent, TagName, and Children. Figure 2 Values to Control Access to the Page DOM Value Disabled Enabled SameDomain Description The application is not allowed access to the DOM of the underlying page. The application is allowed access to the DOM of the underlying page. The application is allowed access to the DOM of the underlying page only if the page comes from the same domain of the Silverlight XAP application. This is the default setting. EnableRedrawRegions HtmlAccess InitParameters MaxFrameRate MinimumVersion Figure 3 Members of the HtmlPage Class Member BrowserInformation Description Gets general information about the browser, such as name, version, and operating system. Provides access to the document object of the page. Indicates whether access to the page DOM is allowed. Gets a reference to the Silverlight object. Provides access to the window object of the page. Registers a managed type as available for creation from JavaScript code. Registers a managed object as scriptable by JavaScript code in the page. Unregisters a type that was previously registered as createable using the RegisterCreteableType method. Cutting Edge PluginBackground PluginNotInstalledTemplate ScaleMode Document IsEnabled Plugin Window RegisterCreateableType RegisterScriptableObject UnregisterCreateableType ScriptType Source SplashScreenSource Windowless 32 msdn magazine

Table of Contents Feed for the Digital Edition of MSDN Magazine - November 2008

Contents MSDN Magazine - November 2008 Toolbox CLR Inside Out Data Points Cutting Edge Security Briefs Test Your Security IQ Agile SDL Access Control Utility Spotlight RIA Test Run Wicked Code Foundations Team System End Bracket

MSDN Magazine - November 2008

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