Android application development cookbook: 93 recipes for building winning apps

377 Pages·2013·11.94 MB·English

by  Wei-Meng Lee

Table of Contents
Cover
Chapter 1: Android Fundamentals
Recipe 1.1 Linking Activities
Recipe 1.2 Passing Data Between Activities
Recipe 1.3 Passing Objects Between Activities
Recipe 1.4 Sending and Receiving Broadcasts
Recipe 1.5 Assigning Priorities to Broadcast Receivers
Recipe 1.6 Auto-Launching Your Application at Boot Time
Recipe 1.7 Calling Built-In Apps
Chapter 2: Using Views to Design the User Interface
Recipe 2.1 Using Buttons
Recipe 2.2 Using Image Buttons
Recipe 2.3 Using Radio Buttons
Recipe 2.4 Using CheckBoxes
Recipe 2.5 Implementing a Star Rating System
Recipe 2.6 Using AutoCompleteTextView
Recipe 2.7 Displaying Web Pages
Recipe 2.8 Using the TimePicker
Recipe 2.9 Using the DatePicker
Recipe 2.10 Using LinearLayout for View Positioning
Recipe 2.11 Using RelativeLayout for View Positioning
Recipe 2.12 Using FrameLayout for View Positioning
Recipe 2.13 Using TableLayout for View Positioning
Recipe 2.14 Using the ScrollView
Recipe 2.15 Displaying Context and Options Menus
Recipe 2.16 Displaying Dialogs
Chapter 3: Displaying Lists of Items and Images
Recipe 3.1 Displaying a List of Items Using the ListView
Recipe 3.2 Customizing the ListView
Recipe 3.3 Displaying Multiple ListViews
Recipe 3.4 Creating Custom ListViews
Recipe 3.5 Further Customizing Each Row with Additional
TextViews
Recipe 3.6 Displaying a List of Items Using the Spinner View
Recipe 3.7 Displaying a List of Images
Recipe 3.8 Animating the Changing of Images Using the
ImageSwitcher
Recipe 3.9 Displaying Images Using the GridView
Chapter 4: Telephony
Recipe 4.1 Calling from Your Application
Recipe 4.2 Monitoring the State of the Phone
Recipe 4.3 Monitoring Phone State in the Background
Recipe 4.4 Blocking Outgoing Calls
Recipe 4.5 Auto-Answering an Incoming Call
Recipe 4.6 Switching to Airplane Mode
Recipe 4.7 Getting the Phone Number, IMEI, and SIM Card ID
Recipe 4.8 Enabling Bluetooth
Chapter 5: Messaging
Recipe 5.1 Sending SMS Messages Through the Built-in
Messaging Application
Recipe 5.2 Sending SMS Messages Programmatically in Your
Android Application
Recipe 5.3 Monitoring the Status of Sent SMS Messages
Programmatically
Recipe 5.4 Monitoring Outgoing SMS Messages
Chapter 6: Network Programming
Recipe 6.1 Connecting to Servers Using HTTP GET
Recipe 6.2 Connecting to Servers Using HTTP POST
Recipe 6.3 Downloading Binary Data Using HTTP
Recipe 6.4 Consuming XML Web Services
Recipe 6.5 Consuming JSON Web Services
Recipe 6.6 Getting the IP Address of the Device
Recipe 6.7 Creating a Socket Server
Recipe 6.8 Creating a Socket Client
Recipe 6.9 Checking for the Availability of Bluetooth
Recipe 6.10 Monitoring the State of Bluetooth
Chapter 7: Using Google Maps
Recipe 7.1 Displaying Google Maps
Recipe 7.2 Zooming in and out of Google Maps
Recipe 7.3 Changing Map Modes
Recipe 7.4 Navigating the Map to a Particular Location
Recipe 7.5 Adding Markers to the Map
Recipe 7.6 Finding a User-Friendly Address Using Reverse
Geocoding, and Vice Versa
Chapter 8: Location-Based Data Services
Recipe 8.1 Obtaining Geographical Location Using GPS, Wi-Fi,
or Cellular Networks
Recipe 8.2 Choosing the Best Location Provider to Use
Recipe 8.3 Monitoring a Location
Recipe 8.4 Using a BroadcastReceiver to Obtain Locations
Chapter 9: Accessing the Hardware
Recipe 9.1 Capturing Pictures with the Camera
Recipe 9.2 Detecting the Presence of Hardware Features
Recipe 9.3 Checking Network State
Recipe 9.4 Turning GPS On/Off
Recipe 9.5 Capturing Hardware Buttons Programmatically
Recipe 9.6 Switching on the Flashlight
Chapter 10: Persisting Data
Recipe 10.1 Saving and Loading User Preferences
Recipe 10.2 Creating a Preference Screen
Recipe 10.3 Saving Files to the Data Directory
Recipe 10.4 Saving Files to the Cache Directory
Recipe 10.5 Saving Files to External Storage
Recipe 10.6 Attaching Files to Your Project
Recipe 10.7 Creating and Using SQLite Databases
Programmatically
Chapter 11: Deploying Your Android Applications
Recipe 11.1 Localizing Your Application
Recipe 11.2 Exporting Your Application as an APK File
Recipe 11.3 Deploying Your App Through E-mail
Recipe 11.4 Deploying Your App Through the Web
Recipe 11.5 Deploying Your App Through an SD Card
Introduction
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Chapter 1
Android Fundamentals
In this chapter, you learn about the fundamental topics in Android that most
developers need to know, including how to link to other applications using the
Intent object, how to communicate with other applications (or parts of the same
application) using broadcast receivers, and how to pass data between activities.
Recipe 1.1 Linking Activities
Android Versions
Level 1 and above
Permissions
None
Source Code to Download at Wrox.com
Linking.zip
Unless you are writing a Hello World application, chances are good that your
application contains several activities that you need to connect in order to form a
cohesive application. This recipe shows you the various ways to link to another
activity in your Android application.
Solution
Suppose you have two activities in your application. The following
AndroidManifest.xml file shows the two activities classes, MainActivity and
Activity2: <manifest
xmlns:android="http://schemas.android.com/apk/res/android"
package="net.learn2develop.linking" android:versionCode="1"
android:versionName="1.0" > <uses-sdk android:minSdkVersion="8"
android:targetSdkVersion="15" > <application
android:icon="@drawableic_launcher"
android:label="@string/app_name" android:theme="@style/AppTheme" >
<activity android:name=".MainActivity"
android:label="@string/title_activity_main" > <intentfilter>
<action android:name="android.intent.action.MAIN" /> <category
android:name="android.intent.category.LAUNCHER" /> </intentfilter>
</activity> <activity android:name=".Activity2"
android:label="@string/app_name" > <intentfilter> <action
android:name="net.learn2develop.Activity2" /> <category
android:name="android.intent.category.DEFAULT" /> </intentfilter>
</activity> </application> </manifest>
Assuming you are currently in the MainActivity activity, to link to Activity2
you can use the following code snippet: package net.learn2develop.linking;
import android.app.Activity; import android.content.Intent; import
android.os.Bundle; public class MainActivity extends Activity {
@Override public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main); //---link to Activity2---
Intent i = new Intent("net.learn2develop.Activity2");
startActivity(i); } }
To link to another activity, you create an Intent object and set its constructor
to the name (as set in the <action> element in the AndroidManifest.xml file) of
the target activity. Then, call the startActivity() method to launch that
activity.
Alternatively, you can create an Intent object and then call its setAction()
method to set the name of the target activity: //---link to Activity2---
Intent i = new Intent();
i.setAction("net.learn2develop.Activity2"); startActivity(i);
The previous code snippets are useful for calling an activity that is within the
same application, as well as for other applications to call your activity. If you
want to call an activity that is internal to your application, you can also call it
using its class name, like this: //---link to Activity2--- Intent i = new
Intent(this, Activity2.class);
If you do not want other activities to call your activity from outside your
application, simply remove the <action> element within the <intentfilter>
element: <activity android:name=".Activity2"
android:label="@string/app_name" > <intentfilter> <!-- <action
android:name="net.learn2develop.Activity2" /> --> <category
android:name="android.intent.category.DEFAULT" > <intentfilter>
</activity>
If the activity you are trying to call does not exist on the device, your
application will crash, displaying a message like the one shown in Figure 1-1.
Figure 1-1
To ensure that your application does not stop abruptly, call the
startActivity() method together with the Intent.createChooser() method.
The createChooser() method takes an Intent object and a string to display if
an activity cannot be found (or if more than one activity has been found to
satisfy your Intent object): Intent i = new
Intent("net.learn2develop.Activity2");
startActivity(Intent.createChooser(i, "Choose an application"));
Figure 1-2 shows the message that is displayed if an activity cannot be found.
Figure 1-2
Figure 1-3 shows the message that is displayed when more than one activity
has been found.
Note that when using the createChooser() method, you need to specify the
name of the activity (such as net.learn2develop.Activity2 as seen in the
previous example) that you are launching, not its class name. The following code
snippet will not work: //---the following will never link to Activity2-
-- Intent i = new Intent(this, Activity2.class);
startActivity(Intent.createChooser(i, "Choose an application"));
Figure 1-3
Recipe 1.2 Passing Data Between
Activities
Android Versions
Level 1 and above
Permissions
None
Source Code to Download at Wrox.com
PassingData.zip