【Android 开发教程】动态添加Fragments

本章节翻译自《Beginning-Android-4-Application-Development》，如有翻译不当的地方，敬请指出。

原书购买地址http://www.amazon.com/Beginning-Android-4-Application-Development/dp/1118199545/

fragment的真正用处是在程序运行过程中动态地添加。

1. 新建工程。

2. res/layout/main.xml

"1.0" encoding="utf-8"?>
"http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="horizontal" >

3. res/layout/fragment1.xml

"1.0" encoding="utf-8"?>
"http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:background="#00FF00"
    android:orientation="vertical" >


        android:id="@+id/lblFragment1"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="This is fragment #1"
        android:textColor="#000000"
        android:textSize="25sp" />

4. res/layout/fragment2.xml

"1.0" encoding="utf-8"?>
"http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:background="#FFFE00"
    android:orientation="vertical" >


        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="This is fragment #2"
        android:textColor="#000000"
        android:textSize="25sp" />

5. Fragment1.java

public class Fragment1 extends Fragment {
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        // ---Inflate the layout for this fragment---
        return inflater.inflate(R.layout.fragment1, container, false);
    }
}

6. Fragment2.java

public class Fragment2 extends Fragment {
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        // ---Inflate the layout for this fragment---
        return inflater.inflate(R.layout.fragment2, container, false);
    }
}

7. FragmentsActivity.java

public class FragmentsActivity extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        FragmentManager fragmentManager = getFragmentManager();
        FragmentTransaction fragmentTransaction = fragmentManager
                .beginTransaction();

        // ---get the current display info---
        WindowManager wm = getWindowManager();
        Display d = wm.getDefaultDisplay();
        if (d.getWidth() > d.getHeight()) {
            // ---landscape mode---
            Fragment1 fragment1 = new Fragment1();
            // android.R.id.content refers to the content
            // view of the activity
            fragmentTransaction.replace(android.R.id.content, fragment1);
        } else {
            // ---portrait mode---
            Fragment2 fragment2 = new Fragment2();
            fragmentTransaction.replace(android.R.id.content, fragment2);
        }
        // ---add to the back stack---
        fragmentTransaction.addToBackStack(null);
        fragmentTransaction.commit();

    }

}

8. 调试。