是ActivityGroup 的BUG？是对机制理解不深刻？还是逻辑错误？还是。。。不知道了？
首先，先喷一下张艺谋的片子，你他妈太黑了~！什么史上最干净的爱情片，我说是史上最烂的爱情片，只能把无知当纯情。拍电影拍得一点诚意都没有，只会抄韩国的爱情片，记得有一部韩国片跟你这部剧情都差不多~！你就使劲抄吧~！！浪费我160大洋，进去睡觉。 喷到这里。 这一两天碰到一个问题，是一个关于ActivityGroup 的问题，因为项目需要，必须把一个自定义的PreferenceActivity 的界面嵌套在ActivityGroup 里面，可是当我嵌套在里面的时候发现了一个问题。就是PreferenceActivity 的元素不会自动更新UI，这是比较致命的，不知道为什么会出现这个问题。 查了很久，首先我怀疑是我的自定义preference写的有问题，改了一遍，然后再运行还是一样。 单独运行该 preferenceActivity 试了一下，界面可以按照自己的需求更新UI，那就是说不是我这个自定义的preference 的逻辑问题？这点还不敢确定。 那么我怀疑是 ActivityGroup 不允许底下Activity 元素的UI自动更新，那么新建一个普通的Activity 来试试，在这普通的Activity 里面只有一个按钮同样是点击之后弹出对话框然后改变按钮的字，试了一下，。更新成功。。。耶？那么说ActivityGroup 还是允许底下Activity UI 元素更新的？那么问题出在哪呢？ 我又再调试跟踪了代码，确定有执行settext的代码？那是不是说preferenceActivity 和ActivityGroup有冲突？不知道所然，下面贴出我碰到问题的全部代码，由于在公司有加密软件无法将DEMO提供给大家，大家可以根据代码新建一个工程，一起来研究这个问题。 自定义的PreferenceScreenExt 源码： packageasai.cn.seekbardemo; importjava.util.ArrayList; importjava.util.HashMap; importjava.util.List; importandroid.app.Dialog; importandroid.content.Context; importandroid.content.DialogInterface; importandroid.content.SharedPreferences; importandroid.preference.Preference; importandroid.preference.PreferenceGroup; importandroid.util.AttributeSet; importandroid.view.LayoutInflater; importandroid.view.View; importandroid.view.ViewGroup; importandroid.view.View.OnClickListener; importandroid.widget.AdapterView; importandroid.widget.ListView; importandroid.widget.RelativeLayout; importandroid.widget.SimpleAdapter; importandroid.widget.TextView; importandroid.widget.AdapterView.OnItemClickListener; public class PreferenceScreenExtextendsPreferenceGroupimplements OnItemClickListener,DialogInterface.OnDismissListener{ private Dialogdialog; private TextViewtitle,summary; private SharedPreferencesshare; private RelativeLayoutarea; private ListViewlistView; List < Preference > list; private List < HashMap < String,String >> listStr; private CharSequence[]mEntries; private StringmValue; private SimpleAdaptersimple; public PreferenceScreenExt(Contextcontext,AttributeSetattrs){ this (context,attrs,android.R.attr.preferenceScreenStyle); // TODOAuto-generatedconstructorstub } public PreferenceScreenExt(Contextcontext,AttributeSetattrs, int defStyle){ super(context,attrs,android.R.attr.preferenceScreenStyle); // TODOAuto-generatedconstructorstub int resouceId = attrs.getAttributeResourceValue( null , " Entries " , 0 ); if (resouceId > 0 ){ mEntries = getContext().getResources().getTextArray(resouceId); } } @Override protected ViewonCreateView(ViewGroupparent){ // TODOAuto-generatedmethodstu Viewview = LayoutInflater.from(getContext()).inflate( R.layout.preference_screen, null ); area = (RelativeLayout)view.findViewById(R.id.area); share = getPreferenceManager().getSharedPreferences(); title = (TextView)view.findViewById(R.id.title); summary = (TextView)view.findViewById(R.id.summary); title.setText(getTitle()); summary.setText(share.getString(getKey(),getSummary() == null ? "" :getSummary().toString())); area.setOnClickListener( new OnClickListener(){ @Override public void onClick(Viewv){ // TODOAuto-generatedmethodstub showDialog(); } }); return view; } public void bindView(ListViewlistview){ int length = mEntries.length; int i = 0 ; listStr = new ArrayList < HashMap < String,String >> (); for (i = 0 ;i < length;i ++ ){ HashMap < String,String > map = new HashMap < String,String > (); map.put( " keyname " ,mEntries[i].toString()); listStr.add(map); } simple = new SimpleAdapter(getContext(),listStr,R.layout.dialog_view, new String[]{ " keyname " }, new int []{R.id.text}); listview.setAdapter(simple); listview.setOnItemClickListener( this ); } public void showDialog(){ listView = new ListView(getContext()); bindView(listView); dialog = new Dialog(getContext(),android.R.style.Theme_NoTitleBar); dialog.setContentView(listView); dialog.setOnDismissListener( this ); dialog.show(); } @Override public void onItemClick(AdapterView <?> parent,Viewview, int position, long id){ // TODOAuto-generatedmethodstub mValue = listStr. get (position). get ( " keyname " ).toString(); SharedPreferences.Editoreditor = getEditor(); editor.putString(getKey(),mValue); callChangeListener(mValue); PreferenceScreenExt. this .setOnPreferenceChangeListener( new OnPreferenceChangeListener(){ @Override public booleanonPreferenceChange(Preferencepreference, ObjectnewValue){ // TODOAuto-generatedmethodstub if (temp != null ){ temp.onPreferenceChange(PreferenceScreenExt. this , newValue); } return true ; } }); editor.commit(); dialog.dismiss(); } @Override public void onDismiss(DialogInterfacedialog){ // TODOAuto-generatedmethodstub } private OnPreferenceChangeListenertemp; public interface OnPreferenceChangeListener{ public booleanonPreferenceChange(Preferencepreference,ObjectnewValue); } public void setOnPreferenceChangeListener( OnPreferenceChangeListenerpreference){ this .temp = preference; } public void setValue(Stringvalue){ summary.setText(value); persistString(value); } } 对应的XML布局文件： dialog_view.xml <? xmlversion="1.0"encoding="utf-8" ?> < LinearLayout android:layout_width ="fill_parent" xmlns:android ="http://schemas.android.com/apk/res/android" android:orientation ="vertical" android:gravity ="center" android:layout_height ="fill_parent" > < TextView android:id ="@+id/text" android:layout_marginLeft ="20dp" android:textAppearance ="?android:attr/textAppearanceLarge" android:textSize ="35sp" android:layout_width ="wrap_content" android:layout_height ="wrap_content" > </ TextView > </ LinearLayout > preference_screen.xml <? xmlversion="1.0"encoding="utf-8" ?> < RelativeLayout android:id ="@+id/area" android:gravity ="center_vertical" android:layout_marginTop ="5px" android:clickable ="true" xmlns:android ="http://schemas.android.com/apk/res/android" android:layout_width ="fill_parent" android:layout_height ="wrap_content" > < TextView android:id ="@+id/title" android:layout_marginLeft ="20dp" android:textAppearance ="?android:attr/textAppearanceLarge" android:textSize ="35sp" android:layout_width ="wrap_content" android:layout_height ="wrap_content" > </ TextView > < TextView android:id ="@+id/summary" android:layout_marginRight ="20dp" android:textSize ="35sp" android:textAppearance ="?android:attr/textAppearanceLarge" android:layout_alignParentRight ="true" android:layout_width ="wrap_content" android:layout_height ="wrap_content" > </ TextView > </ RelativeLayout > XML文件夹下的XML文件： preference.xml <? xmlversion="1.0"encoding="utf-8" ?> < PreferenceScreen xmlns:android ="http://schemas.android.com/apk/res/android" > < asai.cn.seekbardemo.PreferenceScreenExt Entries ="@array/country" android:title ="收音区域" android:summary ="美国" android:persistent ="true" android:key ="eeg" > </ asai.cn.seekbardemo.PreferenceScreenExt > </ PreferenceScreen > main.java 对应代码 packageasai.cn.seekbardemo; importandroid.app.ActivityGroup; importandroid.app.LocalActivityManager; importandroid.content.Intent; importandroid.os.Bundle; importandroid.view.View; importandroid.view.Window; importandroid.view.View.OnClickListener; importandroid.widget.Button; importandroid.widget.LinearLayout; public class mainextendsActivityGroupimplementsOnClickListener{ private LocalActivityManagerlm; private LinearLayoutlayout; private Buttonbtn,btn2; @Override protected void onCreate(BundlesavedInstanceState){ // TODOAuto-generatedmethodstub super.onCreate(savedInstanceState); setContentView(R.layout.group); lm = getLocalActivityManager(); btn = (Button)findViewById(R.id.Button01); btn2 = (Button)findViewById(R.id.Button02); btn.setOnClickListener( this ); btn2.setOnClickListener( this ); layout = (LinearLayout)findViewById(R.id.layout); Intentintent = new Intent( this ,seekBarDemo. class ); intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK); Windoww = lm.startActivity( " test " ,intent); Viewv = w.getDecorView(); layout.removeAllViews(); layout.addView(v); } @Override public void onClick(Viewv){ // TODOAuto-generatedmethodstub switch (v.getId()){ case R.id.Button01: Intentintent = new Intent( this ,seekBarDemo. class ); intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP); Windoww = lm.startActivity( " test " ,intent); Viewview = w.getDecorView(); layout.removeAllViews(); layout.addView(view); break ; case R.id.Button02: Intent in = new Intent( this ,test. class ); in .addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP); Windowwin = lm.startActivity( " ww " , in ); Viewvw = win.getDecorView(); layout.removeAllViews(); layout.addView(vw); break ; default : break ; } } } 对应的XML布局文件： group.xml <? xmlversion="1.0"encoding="utf-8" ?> < LinearLayout android:orientation ="vertical" android:layout_width ="fill_parent" android:layout_height ="fill_parent" xmlns:android ="http://schemas.android.com/apk/res/android" > < LinearLayout android:layout_width ="fill_parent" android:gravity ="center_horizontal" android:layout_height ="wrap_content" > < Button android:text ="preference界面" android:id ="@+id/Button01" android:layout_width ="wrap_content" android:layout_height ="wrap_content" ></ Button > < Button android:text ="普通" android:id ="@+id/Button02" android:layout_width ="wrap_content" android:layout_height ="wrap_content" ></ Button > </ LinearLayout > < LinearLayout android:id ="@+id/layout" android:layout_width ="fill_parent" android:layout_height ="wrap_content" ></ LinearLayout > </ LinearLayout > PreferenceActivity 界面代码 SeekBarDemo.java： packageasai.cn.seekbardemo; importandroid.os.Bundle; importandroid.preference.Preference; importandroid.preference.PreferenceActivity; importandroid.preference.Preference.OnPreferenceChangeListener; importandroid.widget.TextView; public class seekBarDemoextendsPreferenceActivity{ private Preferenceeeg; /* *Calledwhentheactivityisfirstcreated. */ @Override public void onCreate(BundlesavedInstanceState){ super.onCreate(savedInstanceState); addPreferencesFromResource(R.xml.preference); finalPreferenceScreenExtpre = (PreferenceScreenExt)findPreference( " eeg " ); pre.setOnPreferenceChangeListener( new OnPreferenceChangeListener(){ @Override public booleanonPreferenceChange(Preferencepreference, ObjectnewValue){ // TODOAuto-generatedmethodstub pre.setValue(String.valueOf(newValue)); return true ; } }); } } 普通的Activity 界面代码test.java： packageasai.cn.seekbardemo; importandroid.app.Activity; importandroid.app.AlertDialog; importandroid.content.DialogInterface; importandroid.os.Bundle; importandroid.view.View; importandroid.view.View.OnClickListener; importandroid.widget.Button; public class testextendsActivity{ @Override protected void onCreate(BundlesavedInstanceState){ // TODOAuto-generatedmethodstub super.onCreate(savedInstanceState); setContentView(R.layout.test); finalButtonbtn = (Button)findViewById(R.id.Button01); btn.setOnClickListener( new OnClickListener(){ @Override public void onClick(Viewv){ // TODOAuto-generatedmethodstub new AlertDialog.Builder(test. this ).setMessage( " 修改 " ).setTitle( " 提示 " ).setPositiveButton(android.R. string .ok, new DialogInterface.OnClickListener(){ @Override public void onClick(DialogInterfacedialog, int which){ // TODOAuto-generatedmethodstub btn.setText( " 修改后的按钮 " ); } }).show(); } }); } } 配置文件： AndroidManifest.xml <? xmlversion="1.0"encoding="utf-8" ?> < manifest xmlns:android ="http://schemas.android.com/apk/res/android" package ="asai.cn.seekbardemo" android:versionCode ="1" android:versionName ="1.0" > < application android:icon ="@drawable/icon" android:label ="@string/app_name" > < activity android:name =".main" 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 =".test" android:label ="@string/app_name" > < intent-filter > < category android:name ="android.intent.category.LAUNCHER" /> </ intent-filter > </ activity > < activity android:name =".seekBarDemo" android:label ="@string/app_name" > < intent-filter > < category android:name ="android.intent.category.LAUNCHER" /> </ intent-filter > </ activity > </ application > < uses-sdk android:minSdkVersion ="7" /> </ manifest > 本文转自 terry_龙 51CTO博客，原文链接：http://blog.51cto.com/terryblog/397862，如需转载请自行联系原作者
