Visual studio 2010 part 31 ppsx

290 Microsoft Visual Studio 2010: A Beginner’s Guide Navigating the Silverlight Designer The underlying technology for displaying the UI is XML Application Markup Language (XAML), pronounced “Zamel.” Appendix A contains an introduction to XML, and Appendix B contains an introduction to XAML if you need to obtain a basic understanding of these two technologies. It would really be helpful for you to review Chapter 8 because you’ll find many of the same controls for layout and display in both Silverlight and WPF . The Silverlight Designer is very similar to the WPF Designer in how you work with controls. Drag and drop from the Toolbox, configure Grids, interact with XAML, and set properties in exactly the same way with Silverlight as with WPF. Since there are so many similarities, I won’t repeat the material covered in Chapter 8 but will build upon previous material, showing you what is special about Silverlight. Using Silverlight Controls Silverlight has strong multimedia support through streaming audio and video. In fact, the Toolbox has controls that make it easy to host your own videos and control the user experience for playing videos. The following steps show how to design a screen that shows a video, as shown in Figure 10-3. 1. Your project starts out with a page named MainPage.xaml, which you should open so the designer is showing. If the XAML editor is showing, click on the Design tab at the bottom of the designer window. 2. You’ll have a default Grid, which you can work with in exactly the same way as the designer for WPF, discussed in Chapter 8. You need to ensure the Grid has two rows, with the top row being large enough to fit the MediaElement and the bottom large enough to fit a single button. Hover over the left margin of the window until you see a grid line appear on the window. Move the grid line vertically until you’ve created two rows, where the bottom row is large enough to hold a button, as shown in Figure 10-3. Click on the window margin when you have the grid line positioned where you want. 3. Find the MediaElement in the Toolbox and drag it onto the top row of the Window in the designer. If you find that you haven’t made the top row large enough, grab the grid line arrow in the left margin and drag it down some more. 4. Set the Name property of the MediaElement control to VideoPlayer. Chapter 10: Designing Silverlight Applications 291 5. The MediaElement control has a Source property that you can set with the URL of a movie. Set the Source property of the MediaElement control to http://mschnlnine .vo.llnwd.net/d1/ch9/8/3/7/0/7/4/OfficeVS10SC1_2MB_ch9.wmv, which is a video that introduces VS 2010. 6. Drag a Button from the Toolbox to the bottom row of the Window in the designer. 7. Set the Name property of the Button to StartStopButton and set the Content property of the Button to Start. In Figure 10-3, you can see a Grid with two rows. The top row holds a MediaElement control and the bottom row holds a button. The name of the Video control is VideoPlayer and the name of the button is StartStopButton. Figure 10-3 Playing Silverlight videos 292 Microsoft Visual Studio 2010: A Beginner’s Guide Double-clicking the StartStopButton control will generate this Click event handler in the code-behind at MainPage.xaml.cs, shown in Listing 10-2. Listing 10-2 Playing and stopping a video C#: using System; using System.Collections.Generic; using System.Linq; using System.Net; using System.Windows; using System.Windows.Controls; using System.Windows.Documents; using System.Windows.Input; using System.Windows.Media; using System.Windows.Media.Animation; using System.Windows.Shapes; namespace SilverlightDemoCS { public partial class MainPage : UserControl { public MainPage() { InitializeComponent(); VideoPlayer.AutoPlay = false; } private bool m_isPlaying = false; private void StartStopButton_Click( object sender, RoutedEventArgs e) { if (m_isPlaying) { VideoPlayer.Stop(); StartStopButton.Content = "Start"; m_isPlaying = false; } else { VideoPlayer.Play(); StartStopButton.Content = "Stop"; Chapter 10: Designing Silverlight Applications 293 m_isPlaying = true; } } } } VB: Partial Public Class MainPage Inherits UserControl Public Sub New() InitializeComponent() VideoPlayer.AutoPlay = False End Sub Dim m_isPlaying As Boolean = False Private Sub StartStopButton_Click( ByVal sender As System.Object, ByVal e As System.Windows.RoutedEventArgs) If (m_isPlaying) Then VideoPlayer.Stop() StartStopButton.Content = "Start" m_isPlaying = False Else VideoPlayer.Play() StartStopButton.Content = "Stop" m_isPlaying = True End If End Sub End Class By default, the MediaElement starts playing the Source video as soon as the application loads, so I set AutoPlay to false in the code-behind constructor. The m_isPlaying field keeps track of whether the MediaElement is playing or not. The Click event handler uses m_isPlaying to toggle between playing and stopped. This is a quick demo of how to work with the MediaElement control, but there’s much more you can do, such as pausing, tracking buffering, checking video position, and more. All you need to do is either capture events of the MediaElement control or use controls like buttons and sliders to interact with MediaElement, as the example shows in Listing 10-2. It would be good practice for you to take what you’ve learned here and add more functionality to the MediaElement control. 294 Microsoft Visual Studio 2010: A Beginner’s Guide Running Silverlight Out-of-Browser (OOB) A new capability of Silverlight 3 is running out-of-browser, meaning that users can load your application onto their desktop without needing to visit the hosting site. T o implement OOB, open the Silverlight application properties by double-clicking the Properties folder in Solution Explorer. You’ll see a window similar to Figure 10-4. Most of the properties in Figure 10-4 have been covered in previous chapters. What’ s different is the section on Silverlight build options, which allows you to set the version and check the box to reduce the size of the *.xap file through caching. However, leave the option to reduce the *.xap file size unchecked if running OOB because it’s not compatible Figure 10-4 Silverlight properties Chapter 10: Designing Silverlight Applications 295 with OOB. The Manifest file describes the contents of the *.xap file. To enable OOB, check the box “Enable running application out of the browser.” Then click the Out-Of- Browser Settings button to display the window shown in Figure 10-5. The OOB settings in Figure 10-5 allow you to set information for the application, the size it will take when running, and variously sized icons that W indows will display. Setting GPU acceleration allows the application to take advantage of the local hardware to optimize graphics. After you save OOB settings and run the application, the user can right-click the application running in the browser and select Install SilverlightDemoCSApplication Onto This Computer, as shown in Figure 10-6. Figure 10-5 Out-of-browser settings 296 Microsoft Visual Studio 2010: A Beginner’s Guide Figure 10-6 Choosing OOB Figure 10-7 Choosing OOB deployment options The next window you’ll see gives options for adding the application to the Start menu and an icon on the desktop. Figure 10-7 shows that both options are checked. When you click OK, Silverlight creates a Start menu item and adds the application to the desktop, as shown in Figure 10-8. When you start the application, it will run in a window rather than the browser. Chapter 10: Designing Silverlight Applications 297 Deploying Silverlight Applications You can deploy a Silverlight application to a Web site, as you would an ASP.NET MVC application. However, you’ll need to ensure the MIME type and policy is in place to ensure the application will run outside of your development environment. If you’re running IIS 7, Silverlight will already be set up. However, if you’re deploying to an IIS 6 server, you must set the MIME type for *.xap files to application/ x-silverlight-app as described in the following steps: 1. Open Administrative Tools | Internet Information Services (IIS) Manager. 2. Under Web Sites, in IIS, right-click on the Web site for your Silverlight application and select Properties. 3. Click the HTTP Headers tab, click MIME Types, and click New. 4. Type .xap as the Extension and application/x-silverlight-app as the MIME type. Click OK three times to close all windows and close IIS. Additionally, you must have a policy file in the root folder of your Web site. There are two types of policy files you can use: crossdomain.xml or clientaccesspolicy.xml. Figure 10-8 Executing an OOB application 298 Microsoft Visual Studio 2010: A Beginner’s Guide The crossdomain.xml policy was created for Adobe Flash applications and can be used with Silverlight applications too. Here’s an example: <!DOCTYPE cross-domain-policy SYSTEM "http://www.macromedia.com/xml/dtds/cross-domain-policy.dtd"> <cross-domain-policy> <allow-access-from domain="*" /> <allow-http-request-headers-from domain="*" headers="*" /> </cross-domain-policy> When designing Silverlight, Microsoft recognized that the crossdomain.xml file wasn’t flexible enough and added support for another type of policy called clientaccesspolicy.xml. Here’s an example: <?xml version="1.0" encoding="utf-8"?> <access-policy> <cross-domain-access> <policy> <allow-from http-methods="*">" <domain uri="*"/> </allow-from> <grant-to> <resource path="/" include-subpaths="true"/> </grant-to> </policy> </cross-domain-access> </access-policy> This clientaccesspolicy.xml listing allows all domains to access all site content that isn’t already secured by other means. You can restrict access by replacing the * in the domain uri with an allowable domain. Further, you can replace the resource path with a path on the site to restrict access to specific folders. Add more policy elements to this file to add more domains and paths. Summary This chapter explains how to run a Silverlight application. You learned how to use the MediaElement control and how to build UIs using the same techniques as in WPF . The OOB functionality allows you to run Silverlight from your desktop. A section describes deploying the Silverlight application to a Web server. We’ve discussed a couple Web technologies already: ASP.NET MVC in Chapter 9 and Silverlight in this chapter. The next chapter shows you another Web technology: WCF Web services. . 290 Microsoft Visual Studio 2010: A Beginner’s Guide Navigating the Silverlight Designer The underlying technology for. of the button is StartStopButton. Figure 10-3 Playing Silverlight videos 292 Microsoft Visual Studio 2010: A Beginner’s Guide Double-clicking the StartStopButton control will generate this Click. you’ve learned here and add more functionality to the MediaElement control. 294 Microsoft Visual Studio 2010: A Beginner’s Guide Running Silverlight Out-of-Browser (OOB) A new capability of Silverlight