Using Intents

Hour2Application for Android in 24, 4th Edition

In hour 2, you learn all about intents. Android intents are used to initiate actions like showing a web page or starting an activity.

Hour 2 shows how to start an activity and to pass data to that activity.

MainActivity shows example intents for

• Starting an Activity called SecondaryActivity
• Showing a location
• Showing a web page

SecondaryActivity can also be started via the implicit intent Action.SEND

Hour 2 Errata

Listings 2.3, 2.5, and 2.9 the book have the same error.

Intent = getIntent();

should be

Intent intent = getIntent();

Listing 2.8

<Intent-filter> 

should be

<intent-filter>

Listing 2.9

 6:          Intent= getIntent();
 7:          if (Intent != null) {
 8:              if (Intent.hasExtra("com.talkingandroid.MESSAGE")) {
 9:                  message = Intent.getStringExtra("com.talkingandroid.MESSAGE");
 10:             } else if (Intent.hasExtra(Intent.EXTRA_TEXT)) {
 11:                 message = Intent.getStringExtra(Intent.EXTRA_TEXT);
 12:             }
 13:         }

should be

6:          Intent intent = getIntent();
7:          if (intent != null) {
8:              if (intent.hasExtra("com.talkingandroid.MESSAGE")) {
9:                  message = intent.getStringExtra("com.talkingandroid.MESSAGE");
10:             } else if (intent.hasExtra(Intent.EXTRA_TEXT)) {
11:                 message = intent.getStringExtra(Intent.EXTRA_TEXT);
12:             }
13:         }