1 Bundle介绍

Bundle主要用于传递数据；它保存的数据，是以key-value(键值对)的形式存在的。

我们经常使用Bundle在Activity之间传递数据，传递的数据可以是boolean、byte、int、long、float、double、string等基本类型或它们对应的数组，也可以是对象或对象数组。当Bundle传递的是对象或对象数组时，必须实现Serializable 或Parcelable接口。下面分别介绍Activity之间如何传递基本类型、传递对象。

2传递基本类型

Bundle提供了各种常用类型的putXxx()/getXxx()方法，用于读写基本类型的数据。Bundle操作基本数据类型的API表格如下所示：

写数据的方法如下：

// "com.test" is the package name of the destination class// "com.test.Activity02" is the full class path of the destination classIntent intent = new Intent().setClassName("com.bundletest", "com.bundletest.Bundle02"); Bundle bundle = new Bundle();bundle.putString("name", "skywang");bundle.putInt("height", 175);intent.putExtras(bundle); startActivity(intent); // end current classfinish();

对应的读数据的方法如下：

Bundle bundle = this.getIntent().getExtras();    String name = bundle.getString("name");  int height = bundle.getInt("height");

3传递Parcelable类型的对象

3.1 Parcelable说明

Parcelable是Android自定义的一个接口，它包括了将数据写入Parcel和从Parcel中读出的API。一个实体（用类来表示），如果需要封装到bundle消息中去，可以通过实现Parcelable接口来实现。

Parcelable和Serializable的API如下表：

3.2 Parcelable接口说明

public interface Parcelable {    //内容描述接口，基本不用管    public int describeContents();    //写入接口函数，打包    public void writeToParcel(Parcel dest, int flags);    //读取接口，目的是要从Parcel中构造一个实现了Parcelable的类的实例处理。因为实现类在这里还是不可知的，所以需要用到模板的方式，继承类名通过模板参数传入。    //为了能够实现模板参数的传入，这里定义Creator嵌入接口,内含两个接口函数分别返回单个和多个继承类实例。    public interface Creator<T> {        public T createFromParcel(Parcel source);        public T[] newArray(int size); }}

3.3 Parcelable接口的实现方法

从parcelable接口定义中，我们可以看到，实现parcelable接口，需要我们实现下面几个方法：
(01)describeContents方法。内容接口描述，默认返回0就可以;
(02)writeToParcel 方法。该方法将类的数据写入外部提供的Parcel中.即打包需要传递的数据到Parcel容器保存，以便从parcel容器获取数据，该方法声明如下：
writeToParcel(Parcel dest, int flags) 具体参数含义见doc文档
(3.)静态的Parcelable.Creator接口，本接口有两个方法：
createFromParcel(Parcelin) 从Parcel容器中读取传递数据值，封装成Parcelable对象返回逻辑层。
newArray(int size) 创建一个类型为T，长度为size的数组，仅一句话（returnnew T[size])即可。方法是供外部类反序列化本类数组使用。

4传递Serializable类型的对象

4.1 Serializable说明

Serializable是一个对象序列化的接口。一个类只有实现了Serializable接口，它的对象才是可序列化的。因此如果要序列化某些类的对象，这些类就必须实现Serializable接口。而实际上，Serializable是一个空接口，没有什么具体内容，它的目的只是简单的标识一个类的对象可以被序列化。

4.2 Serializable接口的实现方法

很简单，只要implements Serializable接口就可以了

5 demo演示程序

下面是对实现上述三种数据传递方式的BundleTest(demo程序)进行简要介绍

5.1 demo概要

BundleTest共包含了4个java文件和2个layout文件(main.xml和main2.xml)

Bundle01.java —— 默认的主Activity窗口。

Bundle02.java —— 主Activity用于跳转的目的窗口。

Book.java —— 实现Parcelable接口的类

Person.java —— 实现Serializable接口的类

main.xml —— Bundle01.java的layout文件

main2.xml —— Bundle02.java的layout文件

工程文件结构如下所示：

5.2代码

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="http://schemas.android.com/apk/res/android"      package="com.bundletest"      android:versionCode="1"      android:versionName="1.0">      <application android:icon="@drawable/icon" android:label="@string/app_name">        <activity android:name=".Bundle01"                  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=".Bundle02"> </activity>    </application>    <uses-sdk android:minSdkVersion="11" /></manifest>

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/app_01"       />   <Button         android:id="@+id/btnBasic"      android:layout_width="fill_parent"      android:layout_height="wrap_content"        android:text="@string/text_basic"       />   <Button         android:id="@+id/btnPar"        android:layout_width="fill_parent"      android:layout_height="wrap_content"        android:text="@string/text_par"     />   <Button         android:id="@+id/btnSer"        android:layout_width="fill_parent"      android:layout_height="wrap_content"        android:text="@string/text_ser"     />   </LinearLayout>

main2.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/app_02"       />   <Button         android:id="@+id/btnBack"       android:layout_width="fill_parent"      android:layout_height="wrap_content"        android:text="@string/text_jump_back"       />    </LinearLayout>

strings.xml

<?xml version="1.0" encoding="utf-8"?><resources>    <string name="hello">Hello MyBundleTest!</string>    <string name="app_name">MyBundleTest</string>    <string name="app_01">Bundle_01</string>    <string name="app_02">Bundle_02</string>    <string name="text_basic">Bundle Basic Data</string>    <string name="text_par">Bundle Parcelable Data</string>    <string name="text_ser">Bundle Seriable Data</string>    <string name="text_jump_back">Jump Back to Bundler01</string></resources>

Bundle01.java

package com.bundletest; import android.app.Activity;import android.os.Bundle;  import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;import android.content.Intent;import android.util.Log; public class Bundle01 extends Activity implements View.OnClickListener{    private static final String TAG = "skywang-->Bundle01";   private Button mBtnBasic = null;    private Button mBtnPar = null;  private Button mBtnSer = null;  @Override    public void onCreate(Bundle savedInstanceState) {       super.onCreate(savedInstanceState);       setContentView(R.layout.main);      mBtnBasic = (Button) findViewById(R.id.btnBasic);       mBtnBasic.setOnClickListener(this);       mBtnPar = (Button) findViewById(R.id.btnPar);       mBtnPar.setOnClickListener(this);         mBtnSer = (Button) findViewById(R.id.btnSer);       mBtnSer.setOnClickListener(this); }   @Override    public void onClick(View view) {        switch (view.getId()) {           case R.id.btnBasic:               sendBasicDataThroughBundle();               break;            case R.id.btnPar:             sendParcelableDataThroughBundle();              break;            case R.id.btnSer:             sendSeriableDataThroughBundle();                break;            default:              break;        }   }   // sent basic data, such as int, strin, etc...  through bundle    private void sendBasicDataThroughBundle(){          // "com.test" is the package name of the destination class        // "com.test.Activity02" is the full class path of the destination class      Intent intent = new Intent().setClassName("com.bundletest", "com.bundletest.Bundle02");             Bundle bundle = new Bundle();     bundle.putString("name", "skywang");      bundle.putInt("height", 175);     intent.putExtras(bundle);               startActivity(intent);      // end current class      finish();   }   // sent object through Pacelable    private void sendParcelableDataThroughBundle(){       Intent intent = new Intent().setClassName("com.bundletest", "com.bundletest.Bundle02");         Book mBook = new Book();        mBook.setBookName("Android");        mBook.setAuthor("skywang");        mBook.setPublishTime(2013);         Bundle mBundle = new Bundle();        mBundle.putParcelable("ParcelableValue", mBook);        intent.putExtras(mBundle);                  startActivity(intent);        finish();    }  // sent object through seriable    private void sendSeriableDataThroughBundle(){          Intent intent = new Intent().setClassName("com.bundletest", "com.bundletest.Bundle02");         Person mPerson = new Person();        mPerson.setName("skywang");        mPerson.setAge(24);         Bundle mBundle = new Bundle();        mBundle.putSerializable("SeriableValue",mPerson);        intent.putExtras(mBundle);                  startActivity(intent);      finish();    } }

Bundle02.java

package com.bundletest; import android.app.Activity;import android.os.Bundle;  import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;import android.content.Intent;import android.util.Log; public class Bundle02 extends Activity implements View.OnClickListener {   private static final String TAG = "skywang-->Bundle02";   private Button mBtnBack = null; @Override    public void onCreate(Bundle savedInstanceState) {       super.onCreate(savedInstanceState);       setContentView(R.layout.main2);         mBtnBack = (Button) findViewById(R.id.btnBack);     mBtnBack.setOnClickListener(this);        receiveBasicData();     receiveParcelableData();        receiveSeriableData();  }   private void receiveBasicData() {        Bundle bundle = this.getIntent().getExtras();                    String name = bundle.getString("name");          int height = bundle.getInt("height");      if (name != null && height != 0)       Log.d(TAG, "receice basic data -- " +                 "name="+name+", height="+height);  }   private void receiveParcelableData() {      Book mBook = (Book)getIntent().getParcelableExtra("ParcelableValue");      if (mBook != null)          Log.d(TAG, "receice parcel data -- " +                    "Book name is: " + mBook.getBookName()+", "+                      "Author is: " + mBook.getAuthor() + ", "+                     "PublishTime is: " + mBook.getPublishTime());   }   private void receiveSeriableData() {        Person mPerson = (Person)getIntent().getSerializableExtra("SeriableValue");        if (mPerson != null)            Log.d(TAG, "receice serial data -- " +                    "The name is:" + mPerson.getName() + ", "+                    "age is:" + mPerson.getAge());      }   @Override    public void onClick(View view) {        switch (view.getId()) {           case R.id.btnBack:            {               // "com.test" is the package name of the destination class                // "com.test.Activity01" is the full class path of the destination class              Intent intent = new Intent().setClassName("com.bundletest", "com.bundletest.Bundle01");             startActivity(intent);              // end current class              finish();           }               break;            default:              break;        }   } }

Book.java

package com.bundletest; import android.os.Parcel;  import android.os.Parcelable;   public class Book implements Parcelable {      private String bookName;      private String author;      private int publishTime;            public String getBookName() {          return bookName;      }      public void setBookName(String bookName) {          this.bookName = bookName;      }      public String getAuthor() {          return author;      }      public void setAuthor(String author) {          this.author = author;      }      public int getPublishTime() {          return publishTime;      }      public void setPublishTime(int publishTime) {          this.publishTime = publishTime;      }            public static final Parcelable.Creator<Book> CREATOR = new Creator<Book>() {          @Override        public Book createFromParcel(Parcel source) {              Book mBook = new Book();              mBook.bookName = source.readString();              mBook.author = source.readString();              mBook.publishTime = source.readInt();              return mBook;          }          @Override        public Book[] newArray(int size) {              return new Book[size];          }      };           @Override    public int describeContents() {          return 0;      }    @Override    public void writeToParcel(Parcel parcel, int flags) {          parcel.writeString(bookName);          parcel.writeString(author);          parcel.writeInt(publishTime);      }  }

Person.java

package com.bundletest; import java.io.Serializable;   public class Person implements Serializable {       private static final long serialVersionUID = 1L;      private String name;      private int age;      public String getName() {          return name;      }      public void setName(String name) {          this.name = name;      }      public int getAge() {          return age;      }      public void setAge(int age) {          this.age = age;      }        }