Handler in Android

My example:

Package Com.wyl.wylhandler;import Android.os.bundle;import Android.os.handler;import android.os.message;import Android.support.v7.app.actionbaractivity;import Android.view.view;import Android.view.View.OnClickListener; Import Android.widget.button;import Android.widget.textview;public class Mainactivity extends Actionbaractivity { TextView TV; Button btn; Message msg;    Handler Handler;        @Override protected void OnCreate (Bundle savedinstancestate) {super.oncreate (savedinstancestate);        Setcontentview (R.layout.activity_main); TV = (TextView) Findviewbyid (R.ID.TEXTVIEWID);  Get TextView btn = (Button) Findviewbyid (R.id.buttonid);  Gets the button myonclicklistener L = new Myonclicklistener ();//Instantiate a listener L Btn.setonclicklistener (L); BTN bindings above gets the listener L} class Myonclicklistener implements onclicklistener{@Override public void OnClick (V   Iew v) {String c = "Wyl";//Set breakpoint with int len = C.length ();//Set Breakpoint with System.out.println ("Len:" +len); 1. Obtain the message MyHandler MyHandler = new MyHandler () through the handler object;    msg = Myhandler.obtainmessage ();    String a = "Zhang Ya lan";//Set breakpoint with msg.what = Len;    Msg.obj = A; Handler SendMessage (msg), Looper automatically removes MSG from the message queue (via the Handlemessage method), Myhandler.sendmessage (msg);//    Handler the MSG into the queue System.out.println ("onclick Thread:" +thread.currentthread (). GetName ()); }//Debug found that loop is in this line of time to get the value Handler in the queue msg} class MyHandler extends handler{@Override public void Handlemes SAGE (Message message) {String name = "Weiyongle";//Set breakpoint with int len2 = Name.length ();//Set Breakpoint with System.out.println ("    Len2: "+len2+", "+" MyHandler: "+thread.currentthread (). GetName ());    Object obj = message.obj;        System.out.println ("MyHandler" printed out: "+obj+" MyHandler the Thread: "+thread.currentthread (). GetName ()); }    }    }

　　

　　

Handler in Android