前言
之前的文章有介紹ActivityGroup,不少人問嵌套使用的問題,同樣的需求在Fragment中也存在,幸好在最新的Android support 包已經支持這一特性!這里就跳過Fragment的介紹,需要注意的是TabActivity已經被標記為棄用(deprecated)。
聲明
歡迎轉載,但請保留文章原始出處:)
博客園:http://www.cnblogs.com
農民伯伯: http://www.cnblogs.com/over140/
正文
一、准備
關於最新的Android兼容包的介紹,參見官網這里。可以在android sdk目錄下extras/android/support/v13/android-support-v13.jar找到最新版,注意是伴隨着Android 4.2一起更新的。
關於嵌套Fragment的介紹,參照官網這里。
二、截圖
三、代碼
FragmentNestActivity.java
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentStatePagerAdapter;
import android.support.v4.app.FragmentTransaction;
import android.support.v4.view.ViewPager;
import android.view.Gravity;
import android.view.LayoutInflater;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.TextView;
/**
* 嵌套Fragment使用
*
* @author 農民伯伯
* @see http://www.cnblogs.com/over140/archive/2013/01/02/2842227.html
*
*/
public class FragmentNestActivity extends FragmentActivity implements OnClickListener {
@Override
protected void onCreate(Bundle arg0) {
super.onCreate(arg0);
setContentView(R.layout.nested_fragments);
findViewById(R.id.btnModule1).setOnClickListener( this);
findViewById(R.id.btnModule2).setOnClickListener( this);
findViewById(R.id.btnModule3).setOnClickListener( this);
findViewById(R.id.btnModule1).performClick();
}
@Override
public void onClick(View v) {
switch (v.getId()) {
case R.id.btnModule1:
addFragmentToStack(FragmentParent.newInstance(0));
break;
case R.id.btnModule2:
addFragmentToStack(FragmentParent.newInstance(1));
break;
case R.id.btnModule3:
addFragmentToStack(FragmentParent.newInstance(2));
break;
}
}
private void addFragmentToStack(Fragment fragment) {
FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
// ft.setCustomAnimations(android.R.anim.slide_in_left, android.R.anim.slide_in_left);
ft.replace(R.id.fragment_container, fragment);
ft.commit();
}
/** 嵌套Fragment */
public final static class FragmentParent extends Fragment {
public static final FragmentParent newInstance( int position) {
FragmentParent f = new FragmentParent();
Bundle args = new Bundle(2);
args.putInt("position", position);
f.setArguments(args);
return f;
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View convertView = inflater.inflate(R.layout.viewpager_fragments, container, false);
ViewPager pager = (ViewPager) convertView.findViewById(R.id.pager);
final int parent_position = getArguments().getInt("position");
// 注意這里的代碼
pager.setAdapter( new FragmentStatePagerAdapter(getChildFragmentManager()) {
@Override
public Fragment getItem( final int position) {
return new Fragment() {
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
TextView convertView = new TextView(getActivity());
convertView.setLayoutParams( new ViewGroup.LayoutParams(ViewGroup.LayoutParams.FILL_PARENT, ViewGroup.LayoutParams.FILL_PARENT));
convertView.setGravity(Gravity.CENTER);
convertView.setTextSize(30);
convertView.setTextColor(Color.BLACK);
convertView.setText("Page " + position);
return convertView;
}
};
}
@Override
public int getCount() {
return 3;
}
@Override
public CharSequence getPageTitle( int position) {
return "Page " + parent_position + " - " + position;
}
});
return convertView;
}
}
}
代碼說明:
這里最關鍵的是方法getChildFragmentManager的支持。這里也演示了Fragment作為嵌套內部類的使用方法。
nested_fragments.xml
< LinearLayout xmlns:android ="http://schemas.android.com/apk/res/android"
android:layout_width ="match_parent"
android:layout_height ="match_parent"
android:orientation ="vertical" >
< FrameLayout
android:id ="@+id/fragment_container"
android:layout_width ="fill_parent"
android:layout_height ="0dip"
android:layout_weight ="1.0"
android:background ="#F7F5DE" >
</ FrameLayout >
< LinearLayout
android:layout_width ="fill_parent"
android:layout_height ="wrap_content"
android:layout_gravity ="bottom"
android:background ="@android:color/black"
android:orientation ="horizontal" >
< ImageView
android:id ="@+id/btnModule1"
android:layout_width ="wrap_content"
android:layout_height ="wrap_content"
android:layout_marginBottom ="3dp"
android:layout_marginLeft ="7dp"
android:layout_marginTop ="3dp"
android:src ="@android:drawable/ic_dialog_dialer" />
< ImageView
android:id ="@+id/btnModule2"
android:layout_width ="wrap_content"
android:layout_height ="wrap_content"
android:layout_marginBottom ="3dp"
android:layout_marginLeft ="7dp"
android:layout_marginTop ="3dp"
android:src ="@android:drawable/ic_dialog_info" />
< ImageView
android:id ="@+id/btnModule3"
android:layout_width ="wrap_content"
android:layout_height ="wrap_content"
android:layout_marginBottom ="3dp"
android:layout_marginLeft ="7dp"
android:layout_marginTop ="3dp"
android:src ="@android:drawable/ic_dialog_alert" />
</ LinearLayout >
</ LinearLayout >
viewpager_fragments.xml
< LinearLayout xmlns:android ="http://schemas.android.com/apk/res/android"
android:layout_width ="match_parent"
android:layout_height ="match_parent" >
< android.support.v4.view.ViewPager
android:id ="@+id/pager"
android:layout_width ="match_parent"
android:layout_height ="match_parent" >
< android.support.v4.view.PagerTitleStrip
android:layout_width ="wrap_content"
android:layout_height ="wrap_content"
android:layout_gravity ="top" />
</ android.support.v4.view.ViewPager >
</ LinearLayout >
代碼說明:
注意!實踐發現ViewPager並不能作為頂層容器,否則會報錯。
四、說明
這是一個典型的嵌套Fragment的例子,最外層使用FrameLayout來實現幾大模塊的切換,內部使用ViewPager實現子模塊的切換,非常實用。
結束
考慮把Support Package, revision 11 更新翻譯一下,強烈建議大家升級到最新的兼容包。
