Android Bundle类
今天发现自己连Bundle类都没有搞清楚,于是花时间研究了一下。
根据google官方的文档(http://developer.android.com/reference/android/os/Bundle.html)
Bundle类是一个key-value对,“A mapping from String values to various Parcelable types.”
类继承关系:
java.lang.Object
android.os.Bundle
Bundle类是一个final类:
public final class
Bundle
extends Objectimplements Parcelable Cloneable
两个activity之间的通讯可以通过bundle类来实现,做法就是:
(1)新建一个bundle类
- Bundle mBundle = new Bundle();
(2)bundle类中加入数据(key -value的形式,另一个activity里面取数据的时候,就要用到key,找出对应的value)
- mBundle.putString("Data", "data from TestBundle");
(3)新建一个intent对象,并将该bundle加入这个intent对象
- Intent intent = new Intent();
- intent.setClass(TestBundle.this, Target.class);
- intent.putExtras(mBundle);
完整代码如下:
android mainfest.xml如下:
- <?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>
两个类如下:intent从TestBundle类发起,到Target类。
类1:TestBundle类:
- 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 stub
- Intent intent = new Intent();
- intent.setClass(TestBundle.this, Target.class);
- Bundle mBundle = new Bundle();
- mBundle.putString("Data", "data from TestBundle");//压入数据
- intent.putExtras(mBundle);
- startActivity(intent);
- }
- };
- button1.setOnClickListener(cl);
- }
- }
类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.target);
- <span style="color:#ff6600;">Bundle bundle = getIntent().getExtras(); </span> //得到传过来的bundle
- String data = bundle.getString("Data");//读出数据
- setTitle(data);
- }
- }
布局文件:
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">测试Bundle用法</string>
- <string name="button">点击跳转</string>
- <string name="target">来到target activity</string>
- </resources>
结果:
跳转结果:
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