菜鸟的博客请多多指教
最近做了一个新功能，更新APK的功能
1、更新APK是一个耗时的任务，我采用了一个服务来做，上次在网上看到服务是在主线程里面，自己也测试了下，数据是真的
所以下载动作还必须在服务里面开一个线程来处理下载任务，在写下载任务的时候，由于经验不够，中间出了很多错，下载要分下载开始，下载中，下载异常，下载结束，
2、在后台下载，对用户来说，是看不见的，无法与用户交流，所以在开启服务的时候我就初始化了一个通知，通知在服务开启是初始化，所以其实通知也是在UI线程中，所以想在下载线程中更新通知进度栏，必须通过机制，来更新通知栏的进度条，但是后来组长又给你我一个需求，在点击通知栏时，在更新界面弹出一个对话框，显示是否要停止更新，这里就涉及到一个新的问题，怎样在Service里面获取Activity呢，找了很多资料，最后找到了一个ActivityManager系统服务，他可以得到指定包的任务栈，得到栈顶的Activity，这样就可以在Service中获取Activity里面了
String MY_PKG_NAME = "com.example.sunny.text333";
int i=0;
ActivityManager manager = (ActivityManager) MyApplication.getInstance().getSystemService(Context.ACTIVITY_SERVICE);
List<ActivityManager.RunningTaskInfo> list = manager.getRunningTasks(100);
for (ActivityManager.RunningTaskInfo info: list){
if(info.topActivity.getPackageName().equals(MY_PKG_NAME) || info.baseActivity.getPackageName().equals(MY_PKG_NAME)){
break;
}
i++;
}
ActivityManager.RunningTaskInfo info=list.get(i);
String className = info.topActivity.getClassName();//得到栈顶的Activity
Intent intent = null;
try {
intent = new Intent(this,Class.forName(className));
intent.addCategory(Intent.CATEGORY_LAUNCHER);
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK| Intent.FLAG_ACTIVITY_SINGLE_TOP);
Bundle bundle = new Bundle();
bundle.putString("flag","取消");
intent.putExtras(bundle);
} catch (ClassNotFoundException e) {
e.printStackTrace();
Log.e("没有找到Activity",""+className);
}
intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP
|Intent.FLAG_ACTIVITY_NEW_TASK);
pendingIntent = PendingIntent.getActivity(this, 0,intent,PendingIntent.FLAG_UPDATE_CURRENT);
notification.contentIntent =pendingIntent;
Log.e("通知的Activity名称",""+className);
下载线程：
class DownloadThread extends Thread {
String url;
MyHandler handler;
public DownloadThread(String url, MyHandler handler) {
this.url = url;
this.handler = handler;
}
@Override
public void run() {
FileOutputStream fos = null;
InputStream io = null;
try {
handler.sendEmptyMessage(0);
URL u = new URL(url);
Log.e("URL","＿＿＿＿＿＿＿＿＿＿＿＿"+u);
HttpURLConnection connection = (HttpURLConnection) u.openConnection();
connection.setConnectTimeout(30000);
connection.setReadTimeout(30000);
io = connection.getInputStream();
if (io != null) {
File file = new File(Environment.getExternalStorageDirectory() + "/" + "mapp.apk");
byte[] buff = new byte[1024];
if (file.exists()) {
file.delete();
} else {
file.createNewFile();
}
fos = new FileOutputStream(file);
int readNum = 0;
int lastPress = 0;//上一次的进度值
int press = 0;//
int fileLength = 0;
int count = 0;//记录文件的读取个数
while (isrunning) {
readNum = io.read(buff);
fileLength = connection.getContentLength();
count += readNum;
press = (int) ((float) count / (float) (fileLength - 1) * 100.0);//下载总大小除以总的大小*100
BigDecimal bd = new BigDecimal(count);
BigDecimal bd1 = new BigDecimal(fileLength - 1);
if (readNum == -1 && bd.toPlainString().equals(bd1.toPlainString())) {// 下载完成
Log.e("sdas", "下载完成");
Message message = new Message();
message.obj = file;
message.what = 2;
handler.sendMessage(message);
break;
} else if (readNum == -1 && !bd.toPlainString().equals(bd1.toPlainString())) {
Log.e("sdas", "下载失败");
handler.sendEmptyMessage(4);
break;
} else if (readNum > 0) {
fos.write(buff, 0, readNum);
// Log.e("sdas", "readNum:" + readNum);
if (press - lastPress >= 1) {
lastPress = press;
// Log.e("sdas", "press:" + press);
Message message = new Message();
message.what = 1;
message.obj = press + "";
handler.sendMessage(message);
}
}
}
fos.flush();
fos.close();
io.close();
}
} catch (MalformedURLException e) {
handler.sendEmptyMessage(4);
e.printStackTrace();
} catch (IOException e) {
handler.sendEmptyMessage(4);
e.printStackTrace();
} finally {
try {
if (fos != null) {
fos.flush();
fos.close();
}
if (io != null) {
io.close();
}
} catch (IOException e) {
}
}
}
}
MyHandler的代码：
class MyHandler extends Handler {
@Override
public void handleMessage(Message msg) {
super.handleMessage(msg);
if (msg != null) {
switch (msg.what) {
case 0:// 初始化通知栏和进度条
views.setTextViewText(R.id.tvProcess, "开始下载……");
views.setTextColor(R.id.tvProcess, Color.BLACK);
views.setProgressBar(R.id.app_down_progressBar, 100, 0, false);
notification.defaults = Notification.DEFAULT_LIGHTS;
notification.contentView = views;
nm.notify(NOTIFICATIO_UPDATE_SOFT, notification);
MyApplication.getInstance().setIsupdateing(true);
break;
case 1:
int download_precent = Integer.parseInt(msg.obj.toString());// 获取下载进度
// 更新状态栏上的下载进度信息
views.setTextViewText(R.id.tvProcess, "已下载" + download_precent + "%");
views.setTextColor(R.id.tvProcess, Color.BLACK);
views.setProgressBar(R.id.app_down_progressBar, 100, download_precent, false);
notification.defaults = Notification.DEFAULT_LIGHTS;
notification.contentView = views;
nm.notify(NOTIFICATIO_UPDATE_SOFT, notification);
MyApplication.getInstance().setIsupdateing(true);
break;
case 2:
MyApplication.getInstance().setIsupdateing(false);
/* if( unIntallapk()){
Log.e("文件卸载",""+unIntallapk());
}*/
Instanll((File) msg.obj);
nm.cancel(NOTIFICATIO_UPDATE_SOFT);
// 停止掉当前的服务
stopSelf();
break;
case 3:// 停止下载
MyApplication.getInstance().setIsupdateing(false);
// 停止掉当前的服务
nm.cancel(NOTIFICATIO_UPDATE_SOFT);
stopSelf();
break;
case 4:// 下载异常
MyApplication.getInstance().setIsupdateing(false);
views.setTextViewText(R.id.tvProcess, "" + "已停止下载");
views.setTextColor(R.id.tvProcess, Color.BLUE);
// 在任务栏不被用户手动删除
notification.flags = Notification.FLAG_AUTO_CANCEL;
// 调用系统默认的声音提示以及震动
notification.defaults = Notification.DEFAULT_ALL;
notification.contentView = views;
nm.cancel(NOTIFICATIO_UPDATE_SOFT);
nm.notify(NOTIFICATIO_UPDATE_SOFT, notification);
break;
default:
break;
}
}
}
}