[Coursera]Programming Mobile Applications for Android Handheld Systems #3 - 2014-01-21@University of Maryland
Week 3 内容：
Last week we saw how Android applications are often designed as chains of Activities, one Activity starts another, and so on. To start an Activity we used Intents. This week we'll talk more about Intents and how Android uses them.
Activities use Intents to start other Activities. But is that always a good thing? Should just any app be allowed to read your contacts list? Or to delete files on your SD card? Sometimes, we need to control when and by whom an Activity is started. Android does this through its Permissions architecture. This week we'll look at how Permissions and created and enforced.
The Fragment Class.
Fragments represent a piece of an Activity's user interface. We'll talk about the Fragment class and what it can do. We'll also talk about the Fragment lifecycle and how it interacts with the Activity lifecycle.
Week 3 需上传：
We have a weekly quiz.
This week we have three Labs, one for each lecture topic. Make sure you read the Lab writeups very carefully. I suggest you implement them in the following order.
In the Intents Lab you will develop a simple application that uses both explicit and implicit Intents to starts other Activities and, in some cases, to receive data from them.
In the Permissions Lab you will develop two simple applications that together both use and define permissions.
In the Fragments Lab you will develop a single application that uses Fragments to create different layouts depending on the screen size of the device.