Android bundle class

Today, I found that I didn't even figure out the bundle class, so I took some time to study it.

According to the official Google documentation (http://developer.android.com/reference/android/ OS /Bundle.html)

The bundle class is a key-value pair, "a mapping from string values to various parcelable types ."

Class inheritance relationship:

Java. Lang. Object
Android. OS. Bundle

The bundle class is a final class:
Public final class
Bundle
Extends objectimplements parcelable cloneable

Communication between two activities can be achieved through the bundle class. The practice is:

(1) create a bundle class

Bundle mBundle = new Bundle(); 

(2) Add data to the bundle class (in the form of key-value, when retrieving data in another activity, key is used to find the corresponding value)

mBundle.putString("Data", "data from TestBundle");

(3) create a new intent object and add this bundle to this intent object

Intent intent = new Intent();  intent.setClass(TestBundle.this, Target.class);  intent.putExtras(mBundle);

The complete code is as follows:

Android mainfest. XML is as follows:

<?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="http://schemas.android.com/apk/res/android"      package="com.tencent.test"      android:versionCode="1"      android:versionName="1.0">    <application android:icon="@drawable/icon" android:label="@string/app_name">        <activity android:name=".TestBundle"                  android:label="@string/app_name">            <intent-filter>                <action android:name="android.intent.action.MAIN" />                <category android:name="android.intent.category.LAUNCHER" />            </intent-filter>        </activity><activity android:name=".Target"></activity>    </application>    <uses-sdk android:minSdkVersion="7" /></manifest> 

The two classes are as follows: intent is initiated from the testbundle class to the target class.

Class 1: testbundle class:

Import android. app. activity; import android. content. intent; import android. OS. bundle; import android. view. view; import android. view. view. onclicklistener; import android. widget. button; public class testbundle extends activity {private button button1; private onclicklistener Cl; Public void oncreate (bundle savedinstancestate) {super. oncreate (savedinstancestate); setcontentview (R. layout. main); button1 = (button) findviewbyid (R. id. button1); CL = new onclicklistener () {@ override public void onclick (view arg0) {// todo auto-generated method stubintent intent = new intent (); intent. setclass (testbundle. this, target. class); bundle mbundle = new bundle (); mbundle. putstring ("data", "data from testbundle"); // press the data intent. putextras (mbundle); startactivity (intent) ;}}; button1.setonclicklistener (CL );}}

Class 2: Target

Import android. app. activity; import android. OS. bundle; public class target extends activity {public void oncreate (bundle savedinstancestate) {super. oncreate (savedinstancestate); setcontentview(r.layout.tar get); bundle = getintent (). getextras (); // get the passed bundle string data = bundle. getstring ("data"); // read data settitle (data );}}

Layout file:

Main. xml

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:orientation="vertical"    android:layout_width="fill_parent"    android:layout_height="fill_parent"    ><TextView      android:layout_width="fill_parent"     android:layout_height="wrap_content"     android:text="@string/hello"    /><Button      android:layout_width="fill_parent"     android:layout_height="wrap_content"     android:text="@string/button"    android:id = "@+id/button1"    /> </LinearLayout>

Target. xml

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:orientation="vertical"    android:layout_width="fill_parent"    android:layout_height="fill_parent"    ><TextView      android:layout_width="fill_parent"     android:layout_height="wrap_content"     android:text="@string/target"    /></LinearLayout>

String. xml

<? XML version = "1.0" encoding = "UTF-8"?> <Resources> <string name = "hello"> Hello world, testbundle! </String> <string name = "app_name"> test bundle usage </string> <string name = "button"> click to jump </string> <string name = "target"> Target activity </string> </resources>

Result:

Jump Result: