Introducing the Third Major Release of Windows Presentation Foundation

最新最全的.Net Framework 3.5教程,WPF教程,欢迎在线阅读学习WPF教程.

Today I'm excited to announce the public beta availability of a major new release of WPF. Since we shipped .NET Framework 3.5 late last year, the team has been hard at work at a new release that adds many supplemental features, fixes a good number of bugs, offers many performance optimizations, and includes a new streamlined installer for a subset profile of the .NET Framework optimized for client scenarios. This new release will ship as part of .NET Framework 3.5 Service Pack 1 later this summer; the beta release is an early preview of these enhancements. In this blog post, I want to provide a broad overview of the new features in this release, focusing on WPF.

Deployment
It's been interesting over the last year or two to see the balance between business and consumer applications developed using WPF. Our early expectation was that WPF would be used primarily for consumer software: the assumption was that animation, rich media, flow documents, 2D and 3D graphics etc. would be primarily of interest to those kinds of applications. In fact, it's been surprising how many enterprise applications have taken advantage of it: architectural patterns such as the data templating and binding model and the separation of UI from code have turned out to be even more compelling reasons to adopt WPF in many cases.

Although Windows Vista includes WPF out of the box, we recognize the need to provide a lightweight way to deploy the platform to desktops running Windows XP. If you're distributing a consumer application over the Internet, it's key to have a setup package that downloads and installs quickly, while providing the user good feedback on its progress. We've put the .NET Framework on a diet, and we've now got a solution for those kinds of applications. As well as the full .NET Framework, we now have a Client Profile that weighs in at about 25MB (roughly the same size as Acrobat Reader), installs in a couple of minutes, and provides a customizable install experience.

How did we reduce the size of the .NET Framework? We removed many assemblies that aren't typically used in client application scenarios (it would be an esoteric client application that needed ASP.NET to execute locally, for instance). The file list was selected over the past year through profiling of numerous client applications; at a high level, it includes the core CLR and base class libraries, WPF, Windows Forms and WCF. We also took advantage of some new compression technology to shrink the package considerably. You can still target the full .NET Framework, of course - this is just an additional option. And it's important to note that the actual shipping assemblies are identical in both the Client Profile and the .NET Framework as a whole.

In Visual Studio 2008 SP1 (also in beta today), you can target the Client Profile through a checkbox in the setup project template. You'll of course get a warning during the build process if you have this option set and your project has a dependency on assemblies missing from the Client Profile. When you compile the application, you will have the option to package the Client Profile installer and your application together into a seamless, unified installer for the best possible experience. We provide a tiny (~200KB) bootstrapper package that keeps to an absolute minimum the time between an end-user clicking the installer and seeing results. We even do a full ngen on the .NET Framework files asynchronously during the install process, so that nothing competing with the startup of your application when it runs for the first time. Despite all this, you should expect to see the full setup complete in a matter of just a few minutes.

How does an application know if it has enough of the .NET Framework to execute? I'm glad you asked that question! Only applications that have been compiled to target the Client Profile will contain the special manifest that indicates that they are supported on machines with just the subset. If you try and execute an application that isn't appropriately marked, the Client Profile will pop up a dialog that will help the end-user update to the full framework. It's also important to note that the Client Profile is fully compatible with ClickOnce.

For end-users who have opted into Windows Update, the .NET Framework Client Profile will be upgraded to the full .NET Framework through a background drizzle process so that applications that target the full framework will be able to take advantage of the increased number of people with WPF installed on their machines.

Lastly, shortly after Visual Studio 2008 SP1 ships, we'll be releasing an add-in that will provide developers with the ability to completely customize the look and feel Client Profile installer - changing background graphics, etc. We're also working with third-party installers such as InstallShield to build Client Profile support into their setup packaging technologies.

One other deployment feature unrelated to the Client Profile - we've slightly loosened up the policy for managed executables run from a network share to allow them to run with full trust. This is a popularly requested change, as Brad Abrams' informal poll testified.