1. 2
Activity & Layout
Anuchit Chalothorn
anoochit@gmail.com
Licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License.

2. Quote
การทําอะไรให ้ถึงขันเทพนัน ไม่เคยง่าย มีแต่ความมุงมัน อดทน
่
อย่างยาวนานเท่านัน ทีจะทําให ้บรรลุได ้
วิถแห่งเทพนันย่อมเต็มไปด ้วยความยากลําบากเสมอ
ี
อันเทพแห่งศาสตร์ใด เริมต ้นต ้องมีความรัก
อย่างงมงายในศาสตร์นัน มีความพากเพียรในการศึกษาจนแตกฉาน
ฝึ กหัดอย่างอดทน
หมันพิจารณาแก ้ไขให ้ศาสตร์แห่งตนย่างเข ้าสูความสมบูรณ์
่
อัจฉริยภาพแค่ชวยลดเวลาแห่งความยากลําบากให ้สันลงเท่านัน
่
แต่หากปราศจากความมุงมันแล ้ว ต่อให ้มีอจฉริยภาพสักเพียงไหน
่ ั
ย่อมไม่สามารถถึงซึงความเป็ นเลิศนันได ้เลย
-- ภุชงค์ อุทโยภาศ

3. Activity
An activity represents the visual representation
of an Android application. activities use views, i.
e. user interface widgets as for example
buttons to create the user interface and to
interact with the user. An Android application
can have several activities.

4. Activity Life Cycle

5. Created

6. Paused and Resumed

7. Stopped

8. Save and Restore State

9. Workshop: Trace Activity Life Cycle
You can use Log or Toast to check life cycle of
activity on each methods;
● onCreate
● onStart
● onResume
● onPause
● onStop
● onDestroy

11. Activity Layout
The user interface for Activities is typically
defined via XML files (layout files).

14. Trick: Single Task
Prevent create instance of Activity, you can
identify launchMode in AndroidManifest.xml
● force for single instance
○ android:launchMode="singleInstance"
● force for single task
○ android:launchMode="singleTask"
● force app to recognize latest state
○ android:alwaysRetainTaskState="true"

15. Trick: Screen Orientation
You can identify the screen orientation by
config in AndroidManifest.xml
● Portrait
○ android:screenOrientation="portrait"
● Landscape
○ android:screenOrientation="landscape"
● Landscape with No Keyboard
○ android:configChange="orientation|kyboardHidden"

16. Multiple Activities
Single App has at least 1 Activity, complex app
has multiple activity. You can call to another
activity using Intent.

17. Workshop: Two Activities
Create App with 2 Activities each activity has a
button for navigate to other activity. Using
Intent to call another activity.
Intent i = new Intent(MainActivity.this,SecondActivity);
startactivity(i);

19. Workshop: Sent data between activity
Create App with 2 Activities, first activity has
text field and button, after push button it'll sent
data in text field to the second activity. Using
putExtra method to create a variable and
identify value;
Intent i = new Intent(getApplicationContext(),
NewActivity.class);
i.putExtra("new_variable_name","value");
startActivity(i);

20. Sent a value
Using putExtra method to create a variable and
identify value;
Intent i = new Intent(getApplicationContext(),
NewActivity.class);
i.putExtra("new_variable_name","value");
startActivity(i);

21. Receive a value
Using getExtras methods to receive value from
variable;
Bundle extras = getIntent().getExtras();
if (extras != null) {
String value = extras.getString("new_variable_name");
}

23. Workshop: Temperature Converter
Create multiple Activity App, temperature
converter between Celsius and Fahrenheit
using the following formula
°C x 9/5 + 32 = °F
(°F - 32) x 5/9 = °C

25. Layouts
Android has different layouts for place an
widgets
● Linear Layout
● Relative Layout
● Frame Layout

26. Workshop: App with Relative Layout
Create single Activity App with Label and
Button using Relative Layout and see how
relative layout work.

28. Workshop: App with Linear Layout
Create single Activity App with Label and
Button using Linear Layout and see how the
linear layout work.

31. Workshop: App with Frame Layout
Create single Activity App with Label and
Button using Frame Layout and see how the
frame layout work.

33. Trick: Dump Layout
You can use DDMS tool to dump screen to see
the layout design and properties

35. End