Android regularly refreshes the UI-Handler

If you want to create a software, you can regularly update the UI interface, find some information, and first paste a simple timer update interface program, which can increase the counter every one second.

Main. xml

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"android:orientation="vertical" android:layout_width="fill_parent"android:layout_height="fill_parent"><TextView android:id="@+id/counter" android:layout_width="fill_parent"android:layout_height="wrap_content" android:text="Count: 0" /><LinearLayout android:orientation="horizontal"android:layout_width="fill_parent" android:layout_height="wrap_content"><Button android:text="start" android:id="@+id/Button01"android:layout_width="fill_parent" android:layout_height="wrap_content" android:layout_weight="1.0"></Button><Button android:text="stop" android:id="@+id/Button02"android:layout_width="fill_parent" android:layout_height="wrap_content" android:layout_weight="1.0" android:enabled="false"></Button><Button android:text="reset" android:id="@+id/Button03"android:layout_width="fill_parent" android:layout_height="wrap_content" android:layout_weight="1.0"></Button></LinearLayout></LinearLayout>

Myhandler. Java

package com.scnu.mc.myhandler;import android.app.Activity;import android.os.Bundle;import android.os.Handler;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;import android.widget.TextView;public class MyHandler extends Activity {private Button btnStart;private Button btnStop;private Button btnReset;private TextView tvCounter;private long count = 0;private boolean run = false;private final Handler handler = new Handler();private final Runnable task = new Runnable() {@Overridepublic void run() {// TODO Auto-generated method stubif (run) {handler.postDelayed(this, 1000);count++;}tvCounter.setText("Count: " + count);}};/** Called when the activity is first created. */@Overridepublic void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.main);btnStart = (Button) findViewById(R.id.Button01);btnStop = (Button) findViewById(R.id.Button02);btnReset = (Button) findViewById(R.id.Button03);tvCounter = (TextView) findViewById(R.id.counter);btnStart.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View v) {// TODO Auto-generated method stubrun = true;updateButton();handler.postDelayed(task, 1000);}});btnStop.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View v) {// TODO Auto-generated method stubrun = false;updateButton();handler.post(task);}});btnReset.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View v) {// TODO Auto-generated method stubcount = 0;run = false;updateButton();handler.post(task);}});}private void updateButton() {btnStart.setEnabled(!run);btnStop.setEnabled(run);}}