大家都知道，由于性能要求，android要求只能在UI线程中更新UI。如果想在其他线程更新UI，我大致总结了4种方式。欢迎补充指正：使用Handler消息传递机制；使用AsyncTask异步任务；使用runOnUiThread(action)方法；使用Handler的post(Runnabelr)方法；以下四种方法用于更新TextView。1.使用Handler消息传递机制packagecom.example.runonuithreadtest;importandroid.app.Activity;importandroid.os.Bundle;importandroid.os.Handler;importandroid.widget.TextView;publicclassMainActivityextendsActivity{privateTextViewtv;Handlerhandler=newHandler(){publicvoidhandleMessage(.os.Messagemsg){if(msg.what==0x123){tv.setText("UpdatedTextView");}};};@OverrideprotectedvoidonCreate(BundlesavedInstanceState){super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);tv=(TextView)findViewById(R.id.tv);newMyThread().start();}classMyThreadextendsThread{@Overridepublicvoidrun(){//延迟更新两秒try{Thread.sleep(2000);}catch(InterruptedExceptione){//TODOAuto-generatedcatchblocke.printStackTrace();}handler.sendEmptyMessage(0x123);}}}2.使用AsyncTask异步任务注意：更新UI的操作只能在onPostExecute(String结果）方法。packagecom.example.runonuithreadtest;importandroid.app.Activity;importandroid.os.AsyncTask;importandroid.os.Bundle;importandroid.widget.TextView;publicclassMainActivityextendsActivity{privateTextViewtv;@OverrideprotectedvoidonCreate(BundlesavedInstanceState){super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);tv=(TextView)findViewById(R.id.tv);newYibu().execute();}classYibuextendsAsyncTask{@OverrideprotectedStringdoInBackground(String...params){try{Thread.sleep(2000);}catch(InterruptedExceptione){//TODOAuto-generatedcatchblocke.printStackTrace();}returnnull;}@OverrideprotectedvoidonPostExecute(Stringresult){//TODOAuto-generatedmethodstubtv.setText("更新后的TextView");}}}3。使用runOnUiThread(action)方法packagecom.example.runonuithreadtest;importandroid.app.Activity;importandroid.os.Bundle;importandroid.widget.TextView;publicclassMainActivityextendsActivity{privateTextViewtv;@OverrideprotectedvoidonCreate(BundlesavedInstanceState){super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);tv=(TextView)findViewById(R.id.tv);newMyThread().start();}classMyThreadextendsThread{@Overridepublicvoidrun(){runOnUiThread(newRunnable(){@Overridepublicvoidrun(){//TODOAuto-generatedmethodstubtry{//延迟两秒更新Thread.sleep(2000);}catch(InterruptedExceptione){e.printStackTrace();}tv.setText("更新后的TextView");}});}}}4.使用Handler的post(Runnabelr)方packagecom.example.runonuithreadtest;importandroid.app.Activity;importandroid.os.Bundle;importandroid.os.Handler;importandroid.widget.TextView;publicclassMainActivityextendsActivity{privateTextViewtv;@OverrideprotectedvoidonCreate(BundlesavedInstanceState){super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);tv=(TextView)findViewById(R.id.tv);Handlerhandler=newHandler();handler.post(newRunnable(){@Overridepublicvoidrun(){try{//延迟两秒更新Thread.sleep(2000);}catch(InterruptedExceptione){e.printStackTrace();}tv.setText("更新的TextView");}});}}
