Android Bundle类
http://blog.csdn.net/randyjiawenjie/article/details/6651437
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:
publicfinalclass
Bundle
extendsObjectimplementsParcelableCloneable
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
<?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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