Android定时刷新UI界面----Handler

本想做一个软件可以对UI界面进行定时更新，找了一些资料，先贴一个简单的定时更新界面程序，可以实现每隔1秒递增计数器的功能。

界面布局文件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() { @Override public void run() { // TODO Auto-generated method stub if (run) { handler.postDelayed(this, 1000); count++; } tvCounter.setText("Count: " + count); } }; /** Called when the activity is first created. */ @Override public 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() { @Override public void onClick(View v) { // TODO Auto-generated method stub run = true; updateButton(); handler.postDelayed(task, 1000); } }); btnStop.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { // TODO Auto-generated method stub run = false; updateButton(); handler.post(task); } }); btnReset.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { // TODO Auto-generated method stub count = 0; run = false; updateButton(); handler.post(task); } }); } private void updateButton() { btnStart.setEnabled(!run); btnStop.setEnabled(run); } }