现在一般的android软件都是需要不断更新的，当你打开某个app的时候，如果有新的版本，它会提示你有新版本需要更新。该小程序实现的就是这个功能。
该小程序的特点是，当有更新时，会弹出一个提示框，点击确定，则在通知来创建一个进度条进行下载，点击取消，则取消更新。
以下是详细代码:
1.创建布局文件notification_item.xml，用于在通知栏生成一个进度条和下载图标。
<?xml version="1.0" encoding="utf-8"?><RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="fill_parent" android:padding="3dp" > <ImageView android:id="@+id/notificationImage" android:layout_width="wrap_content" android:layout_height="wrap_content" android:src="@android:drawable/stat_sys_download" /> <TextView android:id="@+id/notificationTitle" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignParentRight="true" android:layout_toRightOf="@id/notificationImage" android:paddingLeft="6dp" android:textColor="#FF000000" /> <TextView android:id="@+id/notificationPercent" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_below="@id/notificationImage" android:paddingTop="2dp" android:textColor="#FF000000" /> <ProgressBar android:id="@+id/notificationProgress" style="@style/ProgressBarHorizontal_color" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignLeft="@id/notificationTitle" android:layout_alignParentRight="true" android:layout_alignTop="@id/notificationPercent" android:layout_below="@id/notificationTitle" android:paddingLeft="6dp" android:paddingRight="3dp" android:paddingTop="2dp" /></RelativeLayout>
2.创建AppContext类，该类继承自Application。
package com.test.application;import android.app.Application;import android.content.Context;import com.test.update.config.Config;public class AppContext extends Application { private static AppContext appInstance; private Context context; public static AppContext getInstance() { return appInstance; } @Override public void onCreate() { // TODO Auto-generated method stub super.onCreate(); appInstance = this; context = this.getBaseContext();// // 获取当前版本号// try {// PackageInfo packageInfo = getApplicationContext()// .getPackageManager().getPackageInfo(getPackageName(), 0);// Config.localVersion = packageInfo.versionCode;// Config.serverVersion = 1;// 假定服务器版本为2，本地版本默认是1// } catch (NameNotFoundException e) {// e.printStackTrace();// } initGlobal(); } public void initGlobal() { try { Config.localVersion = getPackageManager().getPackageInfo( getPackageName(), 0).versionCode; // 设置本地版本号 Config.serverVersion = 2;// 假定服务器版本为2，本地版本默认是1--实际开发中是从服务器获取最新版本号，android具体与后端的交互见我另///外的博文 } catch (Exception ex) { ex.printStackTrace(); } }}3.创建配置文件类Config.java,在这个类里面定义一些与版本相关的常量
package com.test.update.config;public class Config { //版本信息 public static int localVersion = 0; public static int serverVersion = 0; /* 下载包安装路径 */ public static final String savePath = "/sdcard/test/"; public static final String saveFileName = savePath + "test.apk"; }4.编写更新服务类UpdateServcie.java
package com.test.update;import java.io.File;import java.io.FileOutputStream;import java.io.InputStream;import java.net.HttpURLConnection;import java.net.URL;import android.annotation.SuppressLint;import android.app.Notification;import android.app.NotificationManager;import android.app.PendingIntent;import android.app.Service;import android.content.Intent;import android.net.Uri;import android.os.Environment;import android.os.Handler;import android.os.IBinder;import android.os.Message;import android.widget.RemoteViews;import com.test.update.config.Config;public class UpdateService extends Service { // 标题 private int titleId = 0; // 文件存储 private File updateDir = null; private File updateFile = null; // 下载状态 private final static int DOWNLOAD_COMPLETE = 0; private final static int DOWNLOAD_FAIL = 1; // 通知栏 private NotificationManager updateNotificationManager = null; private Notification updateNotification = null; // 通知栏跳转Intent private Intent updateIntent = null; private PendingIntent updatePendingIntent = null; /*** * 创建通知栏 */ RemoteViews contentView; // 这样的下载代码很多，我就不做过多的说明 int downloadCount = 0; int currentSize = 0; long totalSize = 0; int updateTotalSize = 0; // 在onStartCommand()方法中准备相关的下载工作： @SuppressWarnings("deprecation") @Override public int onStartCommand(Intent intent, int flags, int startId) { // 获取传值 titleId = intent.getIntExtra("titleId", 0); // 创建文件 if (android.os.Environment.MEDIA_MOUNTED.equals(android.os.Environment .getExternalStorageState())) { updateDir = new File(Environment.getExternalStorageDirectory(), Config.saveFileName); updateFile = new File(updateDir.getPath(), getResources() .getString(titleId) + ".apk"); } this.updateNotificationManager = (NotificationManager) getSystemService(NOTIFICATION_SERVICE); this.updateNotification = new Notification(); // 设置下载过程中，点击通知栏，回到主界面 updateIntent = new Intent(this, UpdateActivity.class); updatePendingIntent = PendingIntent.getActivity(this, 0, updateIntent, 0); // 设置通知栏显示内容 updateNotification.icon = R.drawable.ic_launcher; updateNotification.tickerText = "开始下载"; updateNotification.setLatestEventInfo(this, "QQ", "0%", updatePendingIntent); // 发出通知 updateNotificationManager.notify(0, updateNotification); // 开启一个新的线程下载，如果使用Service同步下载，会导致ANR问题，Service本身也会阻塞 new Thread(new updateRunnable()).start();// 这个是下载的重点，是下载的过程 return super.onStartCommand(intent, flags, startId); } @Override public IBinder onBind(Intent arg0) { // TODO Auto-generated method stub return null; } @SuppressLint("HandlerLeak") private Handler updateHandler = new Handler() { @Override public void handleMessage(Message msg) { switch (msg.what) { case DOWNLOAD_COMPLETE: // 点击安装PendingIntent Uri uri = Uri.fromFile(updateFile); Intent installIntent = new Intent(Intent.ACTION_VIEW); installIntent.setDataAndType(uri, "application/vnd.android.package-archive"); updatePendingIntent = PendingIntent.getActivity( UpdateService.this, 0, installIntent, 0); updateNotification.defaults = Notification.DEFAULT_SOUND;// 铃声提醒 updateNotification.setLatestEventInfo(UpdateService.this, "QQ", "下载完成,点击安装。", updatePendingIntent); updateNotificationManager.notify(0, updateNotification); // 停止服务 stopService(updateIntent); case DOWNLOAD_FAIL: // 下载失败 updateNotification.setLatestEventInfo(UpdateService.this, "QQ", "下载完成,点击安装。", updatePendingIntent); updateNotificationManager.notify(0, updateNotification); default: stopService(updateIntent); } } }; public long downloadUpdateFile(String downloadUrl, File saveFile) throws Exception { HttpURLConnection httpConnection = null; InputStream is = null; FileOutputStream fos = null; try { URL url = new URL(downloadUrl); httpConnection = (HttpURLConnection) url.openConnection(); httpConnection .setRequestProperty("User-Agent", "PacificHttpClient"); if (currentSize > 0) { httpConnection.setRequestProperty("RANGE", "bytes=" + currentSize + "-"); } httpConnection.setConnectTimeout(10000); httpConnection.setReadTimeout(20000); updateTotalSize = httpConnection.getContentLength(); if (httpConnection.getResponseCode() == 404) { throw new Exception("fail!"); } is = httpConnection.getInputStream(); fos = new FileOutputStream(saveFile, false); byte buffer[] = new byte[4096]; int readsize = 0; while ((readsize = is.read(buffer)) > 0) { fos.write(buffer, 0, readsize); totalSize += readsize; // 为了防止频繁的通知导致应用吃紧，百分比增加10才通知一次 if ((downloadCount == 0) || (int) (totalSize * 100 / updateTotalSize) - 10 > downloadCount) { downloadCount += 10; updateNotification.setLatestEventInfo(UpdateService.this, "正在下载", (int) totalSize * 100 / updateTotalSize + "%", updatePendingIntent); /*** * 在这里我们用自定的view来显示Notification */ updateNotification.contentView = new RemoteViews( getPackageName(), R.layout.notification_item); updateNotification.contentView.setTextViewText( R.id.notificationTitle, "正在下载"); updateNotification.contentView.setProgressBar( R.id.notificationProgress, 100, downloadCount, false); updateNotificationManager.notify(0, updateNotification); } } } finally { if (httpConnection != null) { httpConnection.disconnect(); } if (is != null) { is.close(); } if (fos != null) { fos.close(); } } return totalSize; } class updateRunnable implements Runnable { Message message = updateHandler.obtainMessage(); public void run() { message.what = DOWNLOAD_COMPLETE; try { // 增加权限<USES-PERMISSION // android:name="android.permission.WRITE_EXTERNAL_STORAGE">; if (!updateDir.exists()) { updateDir.mkdirs(); } if (!updateFile.exists()) { updateFile.createNewFile(); } // 下载函数，以QQ为例子 // 增加权限<USES-PERMISSION // android:name="android.permission.INTERNET">; long downloadSize = downloadUpdateFile( "http://softfile.3g.qq.com:8080/msoft/179/1105/10753/MobileQQ1.0(Android)_Build0198.apk", updateFile); if (downloadSize > 0) { // 下载成功 updateHandler.sendMessage(message); } } catch (Exception ex) { ex.printStackTrace(); message.what = DOWNLOAD_FAIL; // 下载失败 updateHandler.sendMessage(message); } } }}5.编写活动类UpdateActivity
package com.test.update;import com.test.update.config.Config;import android.support.v4.app.Fragment;import android.app.Activity;import android.app.AlertDialog;import android.content.DialogInterface;import android.content.Intent;import android.os.Bundle;import android.util.Log;import android.view.LayoutInflater;public class UpdateActivity extends Activity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); checkVersion(); } /** * 检查更新版本 */ public void checkVersion() { if (Config.localVersion < Config.serverVersion) { Log.i("hgncxzy", "=============================="); // 发现新版本，提示用户更新 AlertDialog.Builder alert = new AlertDialog.Builder(this); alert.setTitle("软件升级") .setMessage("发现新版本,建议立即更新使用.") .setPositiveButton("更新", new DialogInterface.OnClickListener() { public void onClick(DialogInterface dialog, int which) { // 开启更新服务UpdateService // 这里为了把update更好模块化，可以传一些updateService依赖的值 // 如布局ID，资源ID，动态获取的标题,这里以app_name为例 Intent updateIntent = new Intent( UpdateActivity.this, UpdateService.class); updateIntent.putExtra("titleId", R.string.app_name); startService(updateIntent); } }) .setNegativeButton("取消", new DialogInterface.OnClickListener() { public void onClick(DialogInterface dialog, int which) { dialog.dismiss(); } }); alert.create().show(); } else { // 清理工作，略去 // cheanUpdateFile() } }}6.添加权限以及将服务静态加载(在配置文件中加载)。
<uses-permission android:name="android.permission.INTERNET" /> <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" /> <uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS" />注册服务
<service android:name="com.test.update.UpdateService" > </service>完整的AndroidManifest.xml文件如下:
<?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.test.update" android:versionCode="1" android:versionName="1.0" > <uses-sdk android:minSdkVersion="8" android:targetSdkVersion="8" /> <application android:name="com.test.application.AppContext" android:icon="@drawable/ic_launcher" android:label="@string/app_name" > <activity android:name="com.test.update.UpdateActivity" android:label="@string/app_name" > <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity> <service android:name="com.test.update.UpdateService" > </service> </application> <uses-permission android:name="android.permission.INTERNET" /> <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" /> <uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS" /></manifest>
到此编码结束。
源码下载