Android

 

Fragments concept is already have Android3.0 version, 3.0 version is Tab (tablet) specific, version 4.0 or later to continue along the

 

with Fragments, improving Activity flexibility.

 

 In the absence of Fragments

before a screen can only put an Activity, With Fragments after a screen can only put a Anticity, but the Activity can contain multiple Fragments, Fragments therefore also known as sub-Activity, but not the Activity Fragments of subClass, Fragments immediate Object subclass.

 

 

example below an Activity that contains two Fragments left a realistic Title on the right a reality corresponding content.

 

 Activity

Fragments must parasites in the inside, not from the exist Activity and Activity as, Fragments also has its own life cycle, its life cycle is more complicated than the Activity, but the life cycle by Fragments Activity impact, with the Activity end of the end.

 

 

 

1. onAttach (Activity) When in Fragments and associated Activity callbacks can be some restrictions judgment.

 

2. onCreate (Bundle) < / a> and Activity as

 

3. onCreateView (LayoutInflater, ViewGroup, Bundle) View initialized here, and returned to the Fragments

 

4. onActivityCreated (Bundle) < / a> at Activity. onCreate () . namely Activity initialized, this function will be lost Fragments

 

5. onStart ()

 

6. onResume ()

 

1. onPause ()

 

2. onStop ()

 

3. onDestroyView () < / strong>

 

4. onDestroy ()

 

 

5. onDetach ()

 

 

Demo Example:

 

Main Activity

 

 

  

package com.example.fragmenttest; 
 
import com.example.fragmenttest.FragmentTitle.OnTtileClickListener; 
 
import android.os.Bundle; 
import android.app.Activity; 
import android.app.FragmentTransaction; 
import android.database.sqlite.SQLiteDatabase; 
import android.view.Menu; 
 
/** 
 * 主Activity 
 * @author ccf 
 *  
 */ 
public class MainActivity extends Activity implements OnTtileClickListener { 
 
    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
        super.onCreate(savedInstanceState); 
        setContentView(R.layout.activity_main); 
 
    } 
 
    @Override 
    public void onTtitleClick(String content) { 
        FragmentContent content2 = FragmentContent.getInstance(content); 
        getFragmentManager().beginTransaction() 
                .replace(R.id.mContent, content2).commit(); 
    } 
 
    @Override 
    public void onBackPressed() { 
        // TODO Auto-generated method stub 
        super.onBackPressed(); 
    } 
} 
 

 

 

 

 

XML layout file

 

 

  

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    xmlns:tools="http://schemas.android.com/tools" 
    android:layout_width="match_parent" 
    android:layout_height="match_parent" 
> 
 
    <fragment 
        class="com.example.fragmenttest.FragmentTitle" 
        android:id="@+id/titleList" 
        android:layout_width="0dip" 
        android:layout_height="fill_parent" 
        android:layout_weight="1" 
         /> 
 
    <FrameLayout 
        android:id="@+id/mContent" 
        android:layout_width="0dip" 
        android:layout_height="fill_parent" 
        android:layout_weight="2" 
        /> 
 
</LinearLayout> 
  
 
 

 

 

 

fragment is just a placeholder, class attributes, which mark the placeholder Fragments.

 

FrameLayout as the parent container, put to set Fragments.

 

 

 

FragmentTitle Activity on the left of the Title list, inherited ListFragment . , ListFragment holds a ListView

 

  

  
 
package com.example.fragmenttest; 
 
import android.annotation.SuppressLint; 
import android.app.FragmentTransaction; 
import android.app.ListFragment; 
import android.os.Bundle; 
import android.view.LayoutInflater; 
import android.view.View; 
import android.view.ViewGroup; 
import android.widget.ArrayAdapter; 
import android.widget.ListView; 
 
@SuppressLint("NewApi") 
public class FragmentTitle extends ListFragment { 
    private final static String title[] = { "龙骑士", "死灵骑士", "死神来了", "第一滴血" }; 
    private final static String content[] = { 
            "　曾经和平富饶的国度阿拉盖西亚，如今陷在邪恶国王（约翰·马尔科维奇 John Malkovich 饰）的暴政统治下，期待神灵解救敢怒不敢言的人民。一日，农家少年伊拉贡（艾德·斯皮尔斯 Ed Speleers 饰）在林中拾获一枚奇石，不想竟是一枚龙卵，孵出一只蓝色飞龙。伊拉贡为小龙取名"萨菲拉"，遇到先知布鲁姆（杰瑞米·艾恩斯 Jeremy Irons 饰）后，才明白这是一场怎样的机缘——曾经守护这片土地的龙骑士应该回来了，带领人民找回自由。在布鲁姆的指导下，伊拉贡开始学习剑术和驭龙技巧，慢慢从一个普通少年成长为担当重任的龙骑士，前路危险重重，前路通向光明…… ", 
            "莫罗（伊德瑞斯·艾尔巴 Idris Elba 饰）请求布雷斯把小孩丹尼带来神殿以避免恶魔夺取他的灵魂，作为回报他将驱除布雷斯身上的诅咒。丹尼是魔鬼罗尔科的儿子，罗尔科为了把自己的魔力植入儿子体内正派卡里跟追踪逃跑途中的母子两人。正当母子俩被困在采石场的时候，布雷斯到来，他体内的天使爆发了出来，压制住了卡里根。他变成了恶灵骑士，毫不手软的把对手撕成碎片。当战争结束时，三人前往神殿，同时，罗尔科也救醒了死亡边缘的卡里根，并赋予他更可怕的摧毁力，让他再去把丹尼找回来。 在神殿里，莫罗履行协议把布雷斯体内的扎萨罗斯驱赶了出来。但正当他做法时，神殿的牧师试图杀死丹尼——他认为丹尼就是恶魔。还没等他们行动，卡里根就到了。把丹尼带去见了", 
            "某公司组织一次远游，虽然员工们各怀心事，不过他们还是踏上了欢乐的旅途。在经过一座巨大的吊桥时，年轻人山姆（Nicholas D'Agosto 饰）突然看到幻象，幻象中大桥开始垮塌，包括他、同事、朋友在内无数人在这起事故中遇难。当他从幻象中醒来时，周边的种种迹象表明那场灾难即将到来。慌乱之中，他和朱莉（艾玛·贝尔 Emma Bell 饰）、皮特（Miles Fisher 饰）、坎蒂丝（Ellen Wroe 饰）、奥利维亚（Jacqueline MacInnes Wood 饰）等8个人下了车。灾难随即发生，山姆等人成为车上仅有的幸存者。 但是命运并未偏袒这几名幸运儿，死神仍时刻逡巡在他们的周围。死神来了，无论逃到天涯海角也没有用…", 
            "　退伍军人兰博（西尔维斯特•史泰龙Sylvester Stallone 饰）从越南回国，他回到已显得陌生的原居小镇，当地警长（布莱恩•丹内利 Brian Dennehy 饰）看到这个退伍军人的第一眼起，就开始对兰博百般挑剔，甚至将他带回警局肆意侮辱，不堪忍受责打的兰博袭警之后逃跑。警长召集大批警察展开对兰博的追捕，兰博逃至荒山野林之中，不断用自己在越战中掌握的游击战术对警察展开反击，他了一辆武器运输车返回小镇烧毁了商店，法律和武器都不能阻止兰博了。兰博在越战时的长官上校（理查德•克里纳 Richard Crenna 饰）出现，劝说兰博放下枪械，愤懑已久的兰博吼出了自己的困惑与不甘…… " }; 
 
    @Override 
    public void onActivityCreated(Bundle savedInstanceState) { 
        super.onActivityCreated(savedInstanceState); 
        getListView().setBackgroundColor( 
                getResources().getColor(android.R.color.darker_gray)); 
        setListAdapter(new ArrayAdapter<String>(getActivity(), 
                android.R.layout.simple_list_item_1, title)); 
    } 
 
    @Override 
    public View onCreateView(LayoutInflater inflater, ViewGroup container, 
            Bundle savedInstanceState) { 
        return super.onCreateView(inflater, container, savedInstanceState); 
    } 
 
    @Override 
    public void onListItemClick(ListView l, View v, int position, long id) { 
        // TODO Auto-generated method stub 
        super.onListItemClick(l, v, position, id); 
        OnTtileClickListener listener = (OnTtileClickListener) (getActivity()); 
        listener.onTtitleClick(content[position]); 
    } 
 
    @Override 
    public void onPause() { 
        super.onPause(); 
    } 
 
    public interface OnTtileClickListener { 
        public void onTtitleClick(String content); 
    } 
} 
  
 
 

 

 

 

 

FragmentContent the details of the display area on the right.

 

 

  

package com.example.fragmenttest; 
 
import android.annotation.SuppressLint; 
import android.app.Fragment; 
import android.app.ListFragment; 
import android.os.Bundle; 
import android.view.LayoutInflater; 
import android.view.View; 
import android.view.ViewGroup; 
import android.widget.ListView; 
import android.widget.ScrollView; 
import android.widget.TextView; 
 
@SuppressLint("NewApi") 
public class FragmentContent extends Fragment { 
    private String strContent; 
 
    public static FragmentContent getInstance(String strContent) { 
        FragmentContent content = new FragmentContent(); 
        content.strContent = strContent; 
        return content; 
    } 
 
    @Override 
    public View onCreateView(LayoutInflater inflater, ViewGroup container, 
            Bundle savedInstanceState) { 
        super.onCreateView(inflater, container, savedInstanceState); 
        ScrollView scrollView = new ScrollView(getActivity()); 
        TextView mTextView = new TextView(getActivity()); 
        mTextView.setPadding(5, 5, 5, 5); 
        mTextView.setTextSize(15); 
        mTextView.setText(strContent); 
        scrollView.addView(mTextView); 
        scrollView.setBackgroundColor(getResources().getColor(android.R.color.holo_blue_light)); 
        return scrollView; 
    } 
 
    @Override 
    public void onPause() { 
        // TODO Auto-generated method stub 
        super.onPause(); 
    } 
 
} 
  
 
  
 
  
 
 

 

 

 

MainActivity class is very simple. onCreate (Bundle savedInstanceState) function simply calls setContentView ()., plus realized FragmentTitle in custom OnTitleClickListener interfaces, did not do anything other initialization, FragmentTitle initialization is in his own onActivityCreated (Bundle savedInstanceState) in carried out.

 

When Activity calls onCreate (), it will call FragmentTitle onActivityCreated (Bundle savedInstanceState) to complete the initialization of the left side of the title list.

 

  

  
 
  
 
@Override 
    public void onActivityCreated(Bundle savedInstanceState) { 
        super.onActivityCreated(savedInstanceState); 
        getListView().setBackgroundColor( 
                getResources().getColor(android.R.color.darker_gray));//设置背景颜色 
        setListAdapter(new ArrayAdapter<String>(getActivity(), 
                android.R.layout.simple_list_item_1, title));//调用该方法初始化列表 
    } 
  
 
  
 
 

 

 

 

mainActivity achieve FragmentTitle OnTitleClickListener in custom interfaces, FragmentTitle can can

 

onListItemClick (ListView l, View v, int position, long id)

 

 

  

@Override 
    public void onTitleClick(String content) { 
        FragmentContent content2 = FragmentContent.getInstance(content); 
        getFragmentManager().beginTransaction() 
                .replace(R.id.mContent, content2).commit(); 
    } 
 

 

 

 

  

  
 
  
 
@Override 
    public void onListItemClick(ListView l, View v, int position, long id) { 
        // TODO Auto-generated method stub 
        super.onListItemClick(l, v, position, id); 
        OnTitleClickListener listener = (OnTitleClickListener) (getActivity()); 
        listener.onTitleClick(content[position]); 
    } 
  
 
 

 

 

 

how to operate Fragment Activity in it?

 

in onTitleClick (String content) callback function, call getFragmentManager () function, access FragmentManager instance, and then through FragmentManager ; the beginTransaction () function to obtain FragmentTransaction instance.

 

use FragmentTransaction instance of Fragments can operate instance, there are several basic operations

 

add () The Fragments instances and associated Activity

 

hide () that exist in the Activity Fragments shadow hide, corresponding to earnings a function show () to have been shadow possession of Fragments displayed

 

remo ve () the Activity of Fragments removed.

 

replace () with the specified replacement another Fragments Fragments equivalent remo ve () + add ()

 

commit () more action and subject to commit () condition that transaction (Transaction) to take effect.

 

 

When

 

 

Fragments and communication between Activity:

 

1. in Activity By FragmentManager two ways you can get to the corresponding Fragments

 

findFragmentById (int id) through xml layout file for the instance id registered Such Fragments must declare that it is in the layout file id

 

findFragmentByTag (String tag) find instances via tag, tag is changed Fragments instance being FragmentTransaction # add (int containerViewId, Fragment fragment, String tag) as The last parameter passing, tag to maintain its uniqueness, because he is a unique identifier corresponding Fragments instance.

 

 

2. Fragments can be passed getActivity () to obtain the corresponding Activity instance