How Android asynchronously updates the UI using the handler messaging mechanism

Because of the performance requirements, Android requires that the UI be updated only in the UI thread, and to update the UI in other threads, let's introduce a way to use the handler messaging mechanism.

Here's how to update a TextView:

 Packagecom.example.runonuithreadtest;Importandroid.app.Activity;ImportAndroid.os.Bundle;ImportAndroid.os.Handler;ImportAndroid.widget.TextView; Public classMainactivityextendsActivity {PrivateTextView TV; Handler Handler=NewHandler () { Public voidhandlemessage (android.os.Message msg) {if(msg.what==0x123) {Tv.settext ("Updated TextView"); }   }; }; @Overrideprotected voidonCreate (Bundle savedinstancestate) {Super. OnCreate (savedinstancestate);   Setcontentview (R.layout.activity_main); TV=(TextView) Findviewbyid (r.id.tv); NewMyThread (). Start ();} classMyThreadextendsThread {@Override Public voidrun () {//Two-second delay update   Try{Thread.Sleep (2000); } Catch(interruptedexception e) {//TODO auto-generated Catch blockE.printstacktrace (); } handler.sendemptymessage (0x123); } } } 

Of course, the performance test of the app, I am more commonly used this platform: www.ineice.com

How Android asynchronously updates the UI using the handler messaging mechanism