安卓学习记录（1）

publicvoidsave(){Stringdata="Datatosave";FileOutputStreamout=null;BufferedWriterwriter=null;try{		

	out=openFileOutput("data",Context.MODE_PRIVATE);

writer=newBufferedWriter(newOutputStreamWriter(out));writer.write(data);	

}catch(IOExceptione){e.printStackTrace();

try{

if(writer!=null){

writer.close();

}}catch(IOExceptione){				

e.printStackTrace();}

publicStringload(){FileInputStreamin=null;BufferedReaderreader=null;StringBuildercontent=newStringBuilder();try{

in=openFileInput("data");

reader=newBufferedReader(newInputStreamReader(in));Stringline=“”;

while((line=reader.readLine())!=null){content.append(line);

}}catch(IOExceptione){			

e.printStackTrace();}finally{			

if(reader!=null){try{	

reader.close();}catch(IOExceptione){				

e.printStackTrace();}	

SharedPreferences.Editoreditor=getSharedPreferences("data",MODE_PRIVATE).edit();editor.putString("keep",text);editor.commit();

//读取

TextViewv=(TextView)findViewById(R.id.id_textview);SharedPreferencessharedPreferences=getSharedPreferences("data",MODE_PRIVATE);Stringdata=sharedPreferences.getString("keep","null");v.setText(data.toString());

publicclassMyDatabaseHelperextendsSQLiteOpenHelper{//版本1//publicstaticfinalStringCREATE_BOOK="createtableBook("+//"idintegerprimarykeyautoincrement,"//+"authortext,"//+"pricereal,"//+"pagesinteger,"//+"nametext)";//版本3publicstaticfinalStringCREATE_BOOK="createtableBook("+"idintegerprimarykeyautoincrement,"+"authortext,"+"pricereal,"+"pagesinteger,"+"nametext,"+"category_idinteger)";publicstaticfinalStringCREATE_CATEGORY="createtableCategory("+"idintegerprimarykeyautoincrement,"+"category_nametext,"+"category_codeinteger)";privateContextmContext;publicMyDatabaseHelper(Contextcontext,Stringname,SQLiteDatabase.CursorFactoryfactory,intversion){super(context,name,factory,version,null);mContext=context;}@Override//如果用户是从版本2开始安装程序，那么会创建两个表publicvoidonCreate(SQLiteDatabasedb){db.execSQL(CREATE_BOOK);db.execSQL(CREATE_CATEGORY);Toast.makeText(mContext,"Createsucceeded",Toast.LENGTH_SHORT).show();}@Override//对数据库进行升级时候调用,当初始化传入的版本号高于之前的，就会升级publicvoidonUpgrade(SQLiteDatabasedb,intoldVersion,intnewVersion){switch(oldVersion){//如果用户已经安装版本1，现在更新到版本2，只需要再创建第2个表case1:db.execSQL(CREATE_CATEGORY);break;//用户从版本2更新到版本3case2:db.execSQL("altertableBookaddcolumncategory_idinteger");break;default:}}}

privateMyDatabaseHelpermyDatabaseHelper;@OverrideprotectedvoidonCreate(BundlesavedInstanceState){super.onCreate(savedInstanceState);myDatabaseHelper=newMyDatabaseHelper(this,"BookStore.db",null,2);setContentView(R.layout.activity_main);//创建表finalButtoncreateDatabase=(Button)findViewById(R.id.create_database);createDatabase.setOnClickListener(newView.OnClickListener(){@OverridepublicvoidonClick(Viewv){myDatabaseHelper.getWritableDatabase();}});//添加ButtonaddData=(Button)findViewById(R.id.add_data);addData.setOnClickListener(newView.OnClickListener(){@OverridepublicvoidonClick(Viewv){SQLiteDatabasedb=myDatabaseHelper.getWritableDatabase();ContentValuesvalues=newContentValues();//开始组装第一条数据values.put("name","TheDaVinciCode");values.put("author","DanBrown");values.put("pages",454);values.put("price",16.96);db.insert("Book",null,values);//插入第一条数据values.clear();//开始组装第二条数据values.put("name","TheLostSymbol");values.put("author","DanBrown");values.put("pages",510);values.put("price",19.95);db.insert("Book",null,values);}});//更新数据ButtonupdateData=(Button)findViewById(R.id.update_data);updateData.setOnClickListener(newView.OnClickListener(){@OverridepublicvoidonClick(Viewv){SQLiteDatabasedb=myDatabaseHelper.getWritableDatabase();ContentValuescontentValues=newContentValues();contentValues.put("price",10.99);db.update("Book",contentValues,"name=?",newString[]{"TheDaVinciCode"});}});//删除ButtondeleteButton=(Button)findViewById(R.id.delete_data);deleteButton.setOnClickListener(newView.OnClickListener(){@OverridepublicvoidonClick(Viewv){SQLiteDatabasedb=myDatabaseHelper.getWritableDatabase();db.delete("Book","pages>?",newString[]{"500"});}});//查询ButtonqueryButton=(Button)findViewById(R.id.query_data);queryButton.setOnClickListener(newView.OnClickListener(){@OverridepublicvoidonClick(Viewv){SQLiteDatabasedb=myDatabaseHelper.getWritableDatabase();Cursorcursor=db.query("Book",null,null,null,null,null,null);if(cursor.moveToFirst()){do{Stringname=cursor.getString(cursor.getColumnIndex("name"));Stringauthor=cursor.getString(cursor.getColumnIndex("author"));intpages=cursor.getInt(cursor.getColumnIndex("pages"));doubleprice=cursor.getDouble(cursor.getColumnIndex("price"));Log.w("MainActivity","booknameis"+name);Log.w("MainActivity","bookauthoris"+author);Log.w("MainActivity","bookpagesis"+pages);}while(cursor.moveToNext());cursor.close();}}});}

//XML文件

<LinearLayoutxmlns:android="http://schemas.android.com/apk/res/android"android:layout_width="match_parent"android:layout_height="match_parent"android:orientation="vertical"><Buttonandroid:id="@+id/create_database"android:layout_width="match_parent"android:layout_height="wrap_content"android:text="Createdatabase"/><Buttonandroid:id="@+id/add_data"android:layout_width="match_parent"android:layout_height="wrap_content"android:text="Adddata"/><Buttonandroid:id="@+id/update_data"android:layout_width="match_parent"android:layout_height="wrap_content"android:text="Updatedata"/><Buttonandroid:id="@+id/delete_data"android:layout_width="match_parent"android:layout_height="wrap_content"android:text="Deletedata"/><Buttonandroid:id="@+id/query_data"android:layout_width="match_parent"android:layout_height="wrap_content"android:text="Querydata"/></LinearLayout>

//}				

e.printStackTrace();

		}finally{

<providerandroid:name="com.example.demo.DatabaseProvider"android:authorities="com.example.demo.provider"/>

使用了<provider>标签来对DatabaseProvider这个内容供器进行注册，在android:name属性中指定了该类的全名，又在android:authorities属性中指定了该内容提供器的权限

//自定义行为

long[]vibrates={0,1000,1000,1000};notification.vibrate=vibrates;

//闪光灯颜色notification.ledARGB=Color.GREEN;//闪光灯暗去，单位：毫秒notification.ledOnMS=1000;//闪光灯亮起notification.ledOffMS=1000;//指定通知行为notification.flags=Notification.FLAG_SHOW_LIGHTS;

//或者不自定义，设置全部默认行为。

//notification.defaults=Notification.DEFAULT_ALL;

@OverrideprotectedvoidonCreate(BundlesavedInstanceState){super.onCreate(savedInstanceState);setContentView(R.layout.notification_layout);NotificationManagermanager=(NotificationManager)getSystemService(Context.NOTIFICATION_SERVICE);manager.cancel(1);}

privateTextViewsender;privateTextViewcontent;privateIntentFilterintentFilter;privateMessageReceivermessageReceiver;@OverrideprotectedvoidonCreate(BundlesavedInstanceState){super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);sender=(TextView)findViewById(R.id.id_sender);content=(TextView)findViewById(R.id.id_content);intentFilter=newIntentFilter();

//设置优先级，保证第一个接收到intentFilter.setPriority(100);

//activity文件protectedvoidonDestroy(){super.onDestroy();unregisterReceiver(messageReceiver);}classMessageReceiverextendsBroadcastReceiver{@OverridepublicvoidonReceive(Contextcontext,Intentintent){Bundlebundle=intent.getExtras();Object[]obj=(Object[])bundle.get("pdus");SmsMessage[]smsMessage=newSmsMessage[obj.length];for(inti=0;i<smsMessage.length;i++){smsMessage[i]=SmsMessage.createFromPdu((byte[])obj[i]);}Stringaddress=smsMessage[0].getOriginatingAddress();StringfullMessage="";for(SmsMessagemessage:smsMessage){fullMessage+=message.getMessageBody();}sender.setText(address.toString());content.setText(fullMessage.toString());

//拦截通知，不可以继续下发abortBroadcast();

//manifest文件设置权限

<uses-permissionandroid:name="android.permission.RECEIVE_SMS"/>

@Overridepublicvoidrun(){……..}}).start();

Params：在执行AsyncTask需要传入的参数，可用于后台任务中使用。Progress：后台执行任务时，如果需要在界面显示当前进度，可以设置为进度单位。Result：当任务结束时，如果需要返回，可以使用这里的范型作为返回类型publicclassMyAsyncTaskextendsAsyncTask<Void,Integer,Boolean>{@WorkerThreadprotectedBooleandoInBackground(Void...params){这里执行所有耗时操作，但是因为不是主线程，所以不能进行界面操作返回值和继承范型Result的类型是一致的。如果需要更新UI元素，比如说反馈当前任务的执行进度，可以调用publishProgress(Progress...)方法来完成。returntrue;}@MainThread这个方法在后台执行前调用，一般用于进行界面一些初始化操作，比如显示一个进度条protectedvoidonPreExecute(){}@MainThreadprotectedvoidonPostExecute(Resultresult){当后台任务执行完毕并通过return语句进行返回时，这个方法就很快会被调用。返回的数据会作为参数传递到此方法中，可以利用返回的数据来进行一些UI操作，比如说醒任务执行的结果，以及关闭掉进度条对话框等。}@MainThreadprotectedvoidonProgressUpdate(Integer...values){当在后台任务中调用了publishProgress(Progress...)方法后，这个方法就会很快被调用，方法中携带的参数就是在后台任务中传递过来的。在这个方法中可以对UI进行操作，利用参数中的数值就可以对界面元素进行相应地更新}@MainThreadprotectedvoidonCancelled(Resultresult){onCancelled();}}

使用：newMyAsyncTask().execute();

publicclassMyServiceextendsService{privateDownloadBindermBinder=newDownloadBinder();classDownloadBinderextendsBinder{publicvoidstartDownload(){Log.d("MyService","startDownloadexecuted");}publicintgetProgress(){Log.d("MyService","getProgressexecuted");return0;}}@OverridepublicIBinderonBind(Intentintent){Log.w("onBind",getClass().getSimpleName());returnmBinder;}@Override，如果初始化，则首先执行。publicvoidonCreate(){Log.w("onCreate",getClass().getSimpleName());}@Override，startService后调用，如果该服务还没创建，则该方法在onCreate后调用。publicintonStartCommand(Intent_intent,intflags,int_startID){Log.w("onStartCommand",getClass().getSimpleName());returnsuper.onStartCommand(_intent,flags,_startID);}@OverridepublicvoidonDestroy(){Log.w("onDestroy",getClass().getSimpleName());super.onDestroy();}}

使用：

1.先声明一个ServiceConnection对象：

privateMyService.DownloadBinderdownloadBinder;

privatefinalServiceConnectionserviceConnection=newServiceConnection(){@OverridepublicvoidonServiceConnected(ComponentNamename,IBinderservice){downloadBinder=(MyService.DownloadBinder)service;downloadBinder.startDownload();downloadBinder.getProgress();}@OverridepublicvoidonServiceDisconnected(ComponentNamename){}};

2.执行执行绑定：

Intentbind=newIntent(this,MyService.class);bindService(bind,serviceConnection,BIND_AUTO_CREATE);

3.接触绑定：

Intentunbind=newIntent(this,MyService.class);unbindService(serviceConnection);

<serviceandroid:name=".MyService"/>

publicclassMyIntentServiceextendsIntentService{publicMyIntentService(){super("MyIntentService");}@OverridepublicIBinderonBind(Intentintent){returnnull;}//@WorkerThreadprotectedvoidonHandleIntent(Intentintent){Log.w("onHandleIntent","Threadidis"+Thread.currentThread().getId());}}

..

//在manifest文件注册权限：

<serviceandroid:name=".MyIntentService"/>

使用：

IntentintentService=newIntent(this,MyIntentService.class);

startService(intentService);

HttpsURLConnection的使用。

e.g.:

privatestaticfinalintSHOW_RESPONSE=0;privateButtonsendRequest;privateTextViewresponseText;privateHandlerhandler=newHandler(){publicvoidhandleMessage(Messagemsg){switch(msg.what){caseSHOW_RESPONSE:StringBuilderstr=(StringBuilder)msg.obj;responseText.setText(str.toString());break;default:break;}}};@OverrideprotectedvoidonCreate(BundlesavedInstanceState){super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);sendRequest=(Button)findViewById(R.id.id_send_request);responseText=(TextView)findViewById(R.id.id_response);sendRequest.setOnClickListener(newView.OnClickListener(){@OverridepublicvoidonClick(Viewv){sendRequestWithHttpURLConnection();}});}publicvoidsendRequestWithHttpURLConnection(){newThread(newRunnable(){@Overridepublicvoidrun(){HttpsURLConnectionconnection=null;try{URLurl=newURL("https://www.baidu.com");connection=(HttpsURLConnection)url.openConnection();connection.setConnectTimeout(8000);connection.setReadTimeout(8000);connection.setRequestMethod("GET");InputStreaminputStream=connection.getInputStream();BufferedReaderbufferedReader=newBufferedReader(newInputStreamReader(inputStream));StringBuilderstringBuilder=newStringBuilder();Stringline="";while((line=bufferedReader.readLine())!=null){stringBuilder.append(line);}Messagemessage=newMessage();message.what=SHOW_RESPONSE;message.obj=stringBuilder;handler.sendMessage(message);}catch(Exceptione){e.printStackTrace();}finally{if(connection!=null){connection.disconnect();}}}}).start();}

[{"id":"5","version":"5.5","name":"AngryBirds"},{"id":"6","version":"7.0","name":"ClashofClans"},{"id":"7","version":"3.5","name":"HeyDay”}]

//jsonData的值打印出来跟上面一致。

privatevoidparseJSONWithJSONObject(StringjsonData){

try{

JSONArrayjsonArray=newJSONArray(jsonData);for(inti=0;i<jsonArray.length();i++){

JSONObjectjsonObject=jsonArray.getJSONObject(i);

Stringid=jsonObject.getString("id");Stringname=jsonObject.getString("name");Stringversion=jsonObject.getString("version");Log.d("MainActivity","idis"+id);Log.d("MainActivity","nameis"+name);

}}catch(Exceptione){

e.printStackTrace();}

publicclassHttpService{publicinterfaceHttpCallbackListener{voidonFinish(Stringresponse);voidonError(Exceptione);}publicstaticvoidsendHttpRequest(finalStringaddress,finalHttpCallbackListenerlistener){newThread(newRunnable(){@Overridepublicvoidrun(){HttpURLConnectionconnection=null;try{URLurl=newURL(address);connection=(HttpURLConnection)url.openConnection();connection.setRequestMethod("GET");connection.setConnectTimeout(8000);connection.setReadTimeout(8000);connection.setDoInput(true);connection.setDoOutput(true);InputStreamin=connection.getInputStream();BufferedReaderreader=newBufferedReader(newInputStreamReader(in));StringBuilderresponse=newStringBuilder();Stringline;while((line=reader.readLine())!=null){response.append(line);}if(listener!=null){//回调onFinish()方法listener.onFinish(response.toString());}}catch(Exceptione){if(listener!=null){//回调onError()方法 

		listener.onError(e);}}finally{if(connection!=null){connection.disconnect();}}}}).start();}

@OverridepublicvoidonFinish(Stringresponse){}@OverridepublicvoidonError(Exceptione){}});

publicclassMyApplicationextendsApplication{privatestaticContextcontext;	

	@OverridepublicvoidonCreate(){

context=getApplicationContext();}			

publicstaticContextgetContext(){returncontext;			

publicclassPersonimplementsSerializable{

	privateStringname;

privateintage;			

publicStringgetName(){returnname;			

person.setName("Tom");person.setAge(20);Intentintent=newIntent(FirstActivity.this,SecondActivity.class);intent.putExtra("person_data",person);	

startActivity(intent);

//获取对象

Personperson=(Person)getIntent().getSerializableExtra("person_data");

publicclassPersonimplementsSerializable{

	privateStringname;

privateintage;

	publicStringgetName(){returnname;			

	@OverridepublicintdescribeContents(){	

returnnewPerson[size];}