<?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"><!-- 长方形进度条，一开始不可见，直到点击按钮时才出现进度条 --><ProgressBar android:id="@+id/progressBar"style="?android:attr/progressBarStyleHorizontal"mce_style="?android:attr/progressBarStyleHorizontal"android:layout_width="fill_parent"android:layout_height="wrap_content"android:visibility="gone"android:max="100" /><!-- 圆形进度条 --><!--<ProgressBar android:id="@+id/progressBar"style="?android:attr/progressBarStyleLarge"mce_style="?android:attr/progressBarStyleLarge"android:layout_width="wrap_content"android:layout_height="wrap_content" />--><Button android:id="@+id/start" android:text="启动进度条"android:layout_width="wrap_content"android:layout_height="wrap_content" /><Button android:id="@+id/stop" android:text="停止进度条"android:layout_width="wrap_content"android:layout_height="wrap_content" />
</LinearLayout>

package com.ljq.pb;import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.os.Handler;
import android.view.View;
import android.widget.Button;
import android.widget.ProgressBar;public class PbActivity extends Activity {private ProgressBar progressBar = null;private Button start = null, stop = null;// 定义Handler对象private Handler handler = new Handler();@Overridepublic void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.main);progressBar = (ProgressBar) findViewById(R.id.progressBar);progressBar.setProgress(0);start = (Button) findViewById(R.id.start);start.setOnClickListener(new View.OnClickListener() {public void onClick(View v) {handler.post(runnable); //开始执行
            }});stop=(Button)findViewById(R.id.stop);stop.setOnClickListener(new View.OnClickListener() {public void onClick(View v) {handler.removeCallbacks(runnable);//停止执行progressBar.setProgress(0);}});}int pro=0;Runnable runnable=new Runnable(){public void run() {progressBar.setVisibility(View.VISIBLE);pro=progressBar.getProgress()+10;progressBar.setProgress(pro);//如果进度小于100,，则延迟1000毫秒后重复执行runnableif(pro<100){handler.postDelayed(runnable, 1000);}else{progressBar.setVisibility(View.GONE);startActivity(new Intent(PbActivity.this, TestActivity.class));handler.removeCallbacks(runnable);progressBar.setProgress(0);}}};
}