Android Bundle类

https://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:
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);
Bundle bundle = getIntent().getExtras(); //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>

————————————————
版权声明:本文为CSDN博主「randyjiawenjie」的原创文章,遵循 CC 4.0 BY-SA 版权协议,转载请附上原文出处链接及本声明。
原文链接:https://blog.csdn.net/randyjiawenjie/java/article/details/6651437

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