Silverlight 2 applications: a day after Silverlight 3 release
Silverlight 3 release date is approaching, and I’m getting questions what will happen to existing Silverlight 2 applications after it will be released. Also I’m getting questions about the runtime version upgrade.
Let’s see what will happen after Silverlight 3 will be released…
Those who already using Silverlight 2 and getting automatic updates will receive the new runtime automatically. Everyone else need to download and install it manually.
The updated clients will be able to run Silverlight 2 applications as it was before the runtime update. It is possible because of “quirk mode change” – the special mode, that will not enforce Silverlight 3 runtime/features if the runtime detects that the application being run was designed for Silverlight 2. In this way, Silverlight 3 is made “bug compatible” with Silverlight 2 when a Silverlight 2 application is being run (i.e. all bugs from original Silverlight 2 will occur, even if Silverlight 3 already fix them). This will happen until the developers will not compile the application with Silverlight 3 runtime.
Actually, the detection made by querying the “RuntimeVersion” attribute in AppManifest.xml: “RuntimeVersion” reflects the build of Silverlight that was on the developer’s machine when the application was compiled. Thus, if Silvelright 3 runtime will detect for example RuntimeVersion="2.0.31005.0" (Silverlight 2 RTW version) it will execute the application in “quirk mode”, if “RuntimeVersion” will be Silverlight 3 version the application will work in full Silverlight 3 mode.
Now the quick tip for those, who developed Silverlight 2 application:
While updating Silverlight 2 application to use version 3 make sure that you also update update the new “minRuntimeVersion” attribute to the Silverlight 3 ones to ensure the end-user has the correct version.
Stay tuned for more updates/tips
Alex