Android App Development 4

7 May, 2015

Building a Simple User Interface Add a Button Weight Attribute

Exercise1

Last Workshop

2/9 3/9 4/9

Activity An application component that provides a

screen with which users can interact

Starting Another Activity

click

In java directory, select the package com.mycompany.myfirstapp, right-click

Select New > Activity > Blank Activity

Create the Second Activity

Activity Name: DisplayMessageActivity Layout Name: acticity_display_message Title: My Message Hierarchical Parent:

com.mycompany.myfirstapp.MyActivity Package name:com.mycompany.myfirstapp

Create the Second Activity

Edit res/layout/activity_display_message.xml

Edit res/values/strings.xml

Create the Second Activity

Add “Go Next” ButtonCreate the Second Activity

LinearLayout

(horizontal)

ButtonText Field

Button

LinearLayout

(vertical)

LinearLayout

(horizontal)

ButtonText Field

Button

LinearLayout

(vertical)

Width = match_parentHeight = match_paremt

Width = match_parentHeight = match_parent

wrap_content

Add “Go Next” Buttonactivity_my.xml

LinearLayout

(horizontal)

ButtonText Field

Button

LinearLayout

(vertical)

Create the Second Activity

Edit res/layout/activity_my.xml Add onClick attribute

Respond to “Go Next” Button

Edit MyActivity.java Add the goNextActivity() method

Respond to the “Go Next” Button

1. Build an Intent Intent

An object that provides runtime binding between separate components (such as two activities)

2. Add a startActivity Method

goNextActivity() Method

①②

At the top of “MyActivity.java”, import the Intent class

Respond to “Go Next” Button

When you start a new Activity,you need to build an Intent first.

click

click

click

Add a New Button LinearLayout (vertical)

Starting Another Activity Create the Second Activity goNextActivity() Method

Build an Intent Add a startActivity Method

Next Workshop Adding Multimedia to your App

Wrap Up for Today

fin.