Mobile midterm

Question 1

To create a click event for a button, there are 2 ways:
Using onClick============
XML: 
android:onClick="name" 
code: 
public void name (View view) {
          //code
}

using click listener===========
Button btn = findViewById(R.id.name);
btn.setOnClickListener(new View.OnClickListener() {
               @override
               public void onClick (View v) {
               //code
               }
});

Answer

true

Question 2

Which of these layouts are most commonly used in our projects:

Accepted Answer

ConstraintLayout

Accepted Answer

LinerLayout

Answer

FrameLayout

Answer

RelativeLayout

Question 3

Toasts:

Toast.makeText(this, "hello", Toast.LENGTH_LONG).show();

Answer

true

Question 4

OnClick in XML
Advantages:
Easy to implement
Disadvantages:
Only available in OnClick event
callback method must be in parent activity

Answer

true

Question 5

Inner class listener
Advantages:
Can use all events
Disadvantages:
harder to implement

Answer

true

Question 6

Widgets are design time created, when inflated it becomes a view

Answer

true

Question 7

Button hierarchy:
Textview
^
Button
^
CompoundButton
^
CheckBox, RadioButton, Switch, ToggleButton

Answer

true

Question 8

RadioButtons require a parent RadioGroup, which is a subclass of LinerLayout

Answer

true

Question 9

Spinners are a drop down selection of items that can be selected.
Usually uses a string-array in string.xml to populate it.
Can set the array in xml or by using an ArrayAdapter.
Selected values can be get using getSelectedItemPosition or getSelectedItem.

Answer

true

Question 10

this vs MainActivity.this
When the method call is directly within the Activity, use this
When the method call is within an inner class, use MainActivity.this

Answer

true

Question 11

Model View Controller (MVC) is a software design pattern used in developing apps.

Useful for separating areas of responsibility in the app.

Answer

true

Question 12

Model of the MVC, is composed of objects that make up the data of the app.

ie. Student class, Employee class etc

Answer

true

Question 13

View of MVC, is what the user sees and interacts with, handles the look and feel.

Answer

true

Question 14

Controller of MVC, acts as a go-between between view and model. View takes user input, sends to controller, controller has logic to process the input by calling the model objects to process the input.

Answer

true

Question 15

MVC
Model: implemented by programmer
View: XML, widgets
Controller: activities act as controllers

Answer

true

Question 16

Benefits of packages (putting Student class in a folder)
-group classes
-avoid naming conflicts
-protect classes

Answer

true

Question 17

Packages are hierarchical (android.app.Activity, Activity is within app package)
Package names must be unique and lowercase
To access a package, import it (import java.app.package_name)

Answer

true

Question 18

Dont use findViewByID before OnCreate as its initially just a java object before OnCreate is called.

Spinner spn = find.....

protected void OnCreate(...){
...
}

Answer

true

Question 19

Activity is like a screen,
handles interaction with the user
Do not keep instance data (clears when refreshed)

Answer

true

Question 20

Activity lifecycle

Accepted Answer

this

Answer

no

Question 21

Usually when configuration changes in a app occur, OnDestory() is called followed by OnCreate()

Answer

true

Question 22

Bundles can be used on OnSaveInstanceState and OnRestoreInstanceState to prevent the app from resetting its state entirely.

Answer

true

Question 23

OnResume() is a safe place to put SharedPreferences code

Answer

true

Question 24

Pros of SharedPreferences:
quick and easy way to store info
access value using name-value pair
not visible to other apps
cons:
limited data storage
cannot control where data is stored

Answer

true

Question 25

Pros of File I/O:
better for storing large data
can create/store any type of data
multiple places can be stored in
cons:
more coding

Answer

true

Question 26

Pros of SQLite:
flexibly on storage
ability to use querys for data 
performs updates transactionally
robust for storing relational data
cons:
more coding
requires knowledge on SQL
overkill for simple data saving

Answer

true

Question 27

When using SharedPreferences, use must call apply() or commit() to save the changes

clear() will wipe all values

Answer

true

Question 28

Context is an abstract class, implemented by android systems
allows access to specific resources and classes

Answer

true

Question 29

Intents are used to create more loosely coupled apps, and allows your app to call services from other apps

Answer

true

Question 30

Intents can be explicit:
calling a specific services
Or implicit:
let run-time or user pick the activity to handle the intent

Answer

true

Question 31

With Intents, to set the action property, use Intent.ACTION_VIEW
set the data property to be URL needed

Intent (string action)
Intent (string action, URL)
Intent (Context context, class)

Answer

true

Question 32

startActivity - launched and independent of launching activity
startActivityForResult - launched as sub-activity of launching activity and returns a result

Answer

true

Question 33

Returning result from sub-activity using setResult

setResult(int response) - returning a success or failure

setResult(int response, Intent intent) - returning additional information

Answer

true

Question 34

passing data from activity to another activity, using Intent

intent.putExtra("data", "from parent")

Getting the data:
data = intent.getStringExtra("data")

Answer

true

Question 35

ActionBar is the portion on top of the app that contains icons for additional control of the app.

Answer

true

Question 36

Creating an options menu for an app:
creating an xml layout for the menu
hooking up the menu to activity

To respond to the menu interaction:
use onOptionsItemSelected

Answer

true

Question 37

PreferenceActivity:
works along SharedPreferences
is XML-based
uses components which are subclasses of preference
UI file is stored in a folder called xml (use must create it)

Answer

true

Question 38

Preference class:
represents basic UI building block for PreferenceActivity screens

Four main subclasses:
DialogPreference
PreferenceGroup
TwoStatePreference
RingtonePreference

Answer

true

Question 39

Android Studio Stack

Accepted Answer

hai Upma <3

Answer

no

Mobile midterm

Preguntas del test (39)

Información

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