HandlingĬonfiguration changes requires you to take many additional steps toĮnsure that each and every string, layout, drawable, dimension, etc. To handle device configuration changes manually in code. The primary concern is that it requires you The apparent simplicity of thisĪpproach makes it extremely attractive to developers The default destroy-and-recreate behavior by setting the android:configChangesĪttribute in your Android manifest. Perhaps the hackiest and most widely abused workaround is to disable It is vital that we correctly and efficiently retain active objectsĪcross Activity instances when configuration changes occur. Unaware that the old AsyncTask is still running. Might waste valuable resources by firing up the background work again, As if this wasn’t already an issue, the new Activity instance Old Activity instance, completely unaware that a new Activity has beenĬreated. When the AsyncTask eventuallyįinishes its work, it will incorrectly report its results back to the Assume, for example, that an Activity startsĪn AsyncTask and soon after the user rotates the screen, causing theĪctivity to be destroyed and recreated. That Activitys go through as a result stems from the fact that these eventsĪre unpredictable and may occur at any time. One problem with configuration changes and the destroy-and-create cycle Solution, which uses retained Fragments to achieve our goal. We will conclude with sample code illustrating the recommended The flaws of two common approaches to solving the problem. In conjunction with the Activity lifecycle. To answer this question, we will first discuss some of the commonĭifficulties developers face when using long-running background tasks Running Threads, Sockets, and AsyncTasks-across What is the best way to retain active objects-such as This post addresses a common question that is frequently asked on StackOverflow:
0 Comments
Leave a Reply. |