今天發現自己連Bundle類都沒有搞清楚,於是花時間研究了一下。
根據google官方的文檔(http://developer.android.com/reference/android/os/Bundle.html)
Bundle類是一個key-value對,“A mapping from String values to various Parcelable types.”
類繼承關係:
java.lang.Object
android.os.Bundle
Bundle類是一個final類:
public final class
Bundle
extends Objectimplements Parcelable Cloneable
兩個activity之間的通訊可以通過bundle類來實現,做法就是:
(1)建立一個bundle類
Bundle mBundle = new Bundle();
(2)bundle類中加入資料(key -value的形式,另一個activity裡面取資料的時候,就要用到key,找出對應的value)
mBundle.putString("Data", "data from TestBundle");
(3)建立一個intent對象,並將該bundle加入這個intent對象
Intent intent = new Intent(); intent.setClass(TestBundle.this, Target.class); intent.putExtras(mBundle);
完整代碼如下:
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>
兩個類如下:intent從TestBundle類發起,到Target類。
類1:TestBundle類:
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");//壓入資料 intent.putExtras(mBundle); startActivity(intent);} }; button1.setOnClickListener(cl); }}
類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); Bundle bundle = getIntent().getExtras(); //得到傳過來的bundle String data = bundle.getString("Data");//讀出資料 setTitle(data); } }
布局檔案:
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">測試Bundle用法</string> <string name="button">點擊跳轉</string> <string name="target">來到target activity</string></resources>
結果:
跳轉結果: