Basic App

Question 1

What is needed in Adapter class?

Answer 1

Extend adapter 
onCreateViewHolder
onBindViewHolder
getItemCount
new layout for views for items

Question 2

What is the function signature for onCreateViewHolder?

Answer 2

public ViewHolder onCreateViewHolder(ViewGroup, viewType)

Question 3

What does onCreateViewHolder do?

Answer 3

1) gets the id from the layout xml item
2) creates an inflator
3) creates a view from inflator
4) Creates new viewHolder by passing view into viewHolder constructor

Question 4

What is the function signature for onBindViewHolder in the adaptor

Answer 4

public void onBindViewHolder(ViewHolder, position)

Question 5

What does the adaptor constructor take?

Answer 5

number of items

Question 6

What does the onBindViewHolder in the adapator do?

Answer 6

call viewHolder.bind

Question 7

What is in the ViewHolder?

Answer 7

extends the RecyclerView.ViewHolder
gets the text view in the layout from constructor
contains the bind function to set the text of the listView

Question 8

difference between view holder and layout manager

Answer 8

view holder: determines how an individual entry is displayed

layout manager: determines how the collection of items is displayed

Question 9

3 types of layout managers

Answer 9

LinearLayoutManager
GridLayoutManager
StaggeredGridLayoutManager

Question 10

Steps for Recycler View

Answer 10

Add dependency to gradle

Add Recycler view to .xml

Question 11

description of onCreateViewHolder

Answer 11

gets called when each new ViewHolder is created; happens when the RecyclerView is laid out; Enough ViewHolders will be created to fill the screen and allow for scrolling

Question 12

description of onBindViewHolder

Answer 12

called by RecyclerView to display the data at the specified position; update the contents of the ViewHolder to display the correct indices in the last for the particular position given

Question 13

In Main Activity onCreate() to Hook up Layout Manager

Answer 13

1) setContentView(R.layout.activity)
2) get RecyclerView from xml id
3) create new layout manager
4) RecyclerView.setLayoutManager(layoutmanager)
5) Create new adapater
6) RecyclerView.setAdapter(adapter)

Question 14

What does the adapter do?

Answer 14

Sends data to RecyclerView via View Holder
Provides new views
binds data with data source

Question 15

onCreateOptionsMenu signature

Answer 15

public boolean onCreateOptionsMenu(Menu menu)

Question 16

What does onCreateOptionsMenu do?

Answer 16

inflate menu, return true

Question 17

onOptionsItemSelected signature

Answer 17

boolean onOptionsItemSelected(MenuItem item)

Question 18

What does onOptionsItemSelected() do?

Answer 18

get id of MenuItem passed in, if item id == xml id, then do something
else return super.onOptions..()

Question 19

What is passed into the Intent constructor?

Answer 19

1. Context (MainActivity.this)

2. Class (ChildActivity.Class)

Question 20

How to go from one activity to another?

Answer 20

startActivity(intent)

Question 21

How to add data to send with intent

Answer 21

putExtra(String name, String value)

Question 22

How to retrieve data in child sent from parent

Answer 22

getIntent()
if (intent.hasExtra(Intent.EXTRA_TEXT)
string = intent.getStringExtra(Intent.EXTRA_TEXT)

Question 23

verify intent can be launched

Answer 23

intent.resolveActivity(getPackageManager()) != null

Question 24

What two things are included in implicit intents?

Answer 24

An action and a data (what you are trying to do and what info is passed to the action)