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  • 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

    Always Believe Something Beauitful Will Be Happen
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  • 原文地址:https://www.cnblogs.com/Oude/p/12783200.html
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