Android Bundle详解

待我称王封你为后i 2022-08-12 00:12 207阅读 0赞

#     #

# 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][Serializable_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：

![1362500890_6002.jpg][]

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 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();

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：

![1362501930_4748.jpg][]

## 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：

![1362501210_9850.jpg][]

## 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

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;  
        }  
          
    }

## 5.3输出图片 ##

Bundle01.java对应的界面如下：

![1362501241_4101.jpg][]

点击“Bundle Basic Data”、“Bundle Parcelable Data”、“Bundle Seriable Data”均跳转到如下界面，但它们对应的logcat信息不同。

![1362501256_9078.jpg][]

点击“Bundle Basic Data”的logcat如下：

![1362500814_3776.jpg][]

点击“Bundle Parcelable Data”的logcat如下：

![1362502105_3343.jpg][]

点击“Bundle Seriable Data”的logcat如下：

![1362501298_2909.jpg][]

转自：http://www.cnblogs.com/skywang12345/archive/2013/03/06/3165555.html

[Serializable_Parcelable]: http://blog.csdn.net/mer1234567/article/details/7841657
[1362500890_6002.jpg]: https://img-my.csdn.net/uploads/201303/06/1362500890_6002.jpg
[1362501930_4748.jpg]: https://img-my.csdn.net/uploads/201303/06/1362501930_4748.jpg
[1362501210_9850.jpg]: https://img-my.csdn.net/uploads/201303/06/1362501210_9850.jpg
[1362501241_4101.jpg]: https://img-my.csdn.net/uploads/201303/06/1362501241_4101.jpg
[1362501256_9078.jpg]: https://img-my.csdn.net/uploads/201303/06/1362501256_9078.jpg
[1362500814_3776.jpg]: https://img-my.csdn.net/uploads/201303/06/1362500814_3776.jpg
[1362502105_3343.jpg]: https://img-my.csdn.net/uploads/201303/06/1362502105_3343.jpg
[1362501298_2909.jpg]: https://img-my.csdn.net/uploads/201303/06/1362501298_2909.jpg