How Android asynchronously updates the UI using the handler messaging mechanism

due to performance requirements, Android requirements can only be UI Update in Thread UI that you want to update in other threads UI , let us introduce one way: using Handler message passing mechanism .

below updates a textview :

package com.example.runonuithreadtest; import android.app.activity; import  Android.os.bundle; import android.os.handler; import android.widget.textview; public  class MainActivity extends Activity { private TextView tv;  Handler handler = new handler ()  {   public void  Handlemessage (android.os.message msg)  {    if (msg.what==0x123)      {     tv.settext ("Updated TextView");    }   };  };  @Override  protected void oncreate (bundle savedinstancestate)  {    super.oncreate (savedinstancestate);    setcontentview (R.layout.activity_main);    tv =  (TextView)  findviewbyid (r.id.tv);    new mythread (). Start () ;  } class mythread extends thread {    @Override    public void run ()  {     //delay two seconds Update     try {     thread.sleep (2000);     } catch  (interruptedexception e)  {     //  todo auto-generated catch block     e.printstacktrace ();     }    handler.sendemptymessage (0x123);    } } }

Yes , yes. APP performance test, I am more commonly used in this platform: www.ineice.com

How Android asynchronously updates the UI using the handler messaging mechanism