未启动的应用无法监听到系统广播

先说下问题和解决方案：

Q：在 3.1 版本以后，新安装而从未启动过的app不能收到系统的广播(启动完成，网络状态变化之类的)；

解决方案：

1. 将app做成系统应用，直接安装在 system/app 目录下

2. 通过第三方应用，发送带 FLAG_INCLUDE_STOPPED_PACKAGES 的广播给stop状态的自己

下文转载自 http://www.cnblogs.com/fanfeng/p/3236178.html ，很好的讲解了这个问题的原因

Android 开机自启动

首先实现开机自启动：

第一步创建一个广播接收者，如MyBootBroadcastReceiver.java

package com.example;import android.content.BroadcastReceiver;import android.content.Context;import android.content.Intent;public class MyBootBroadcastReceiver extends BroadcastReceiver {    @Override    public void onReceive(Context context, Intent intent) {        Intent startServiceIntent = new Intent(context, MyService.class);        context.startService(startServiceIntent);        //启动应用        //Intent intent = getPackageManager().getLaunchIntentForPackage(packageName);        //context.startActivity(intent);    }}

第二步给receiver配置对应intent-filter

<receiver android:name="MyBootBroadcastReceiver">      <intent-filter>          <action android:name="android.intent.action.BOOT_COMPLETED" />      </intent-filter>  </receiver>

第三步添加权限，缺少这步则无法在Android 3.0及其之前版本上自启动

<uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />

上面的实现有以下【限制】：

1.由于Android系统在外置SD卡加载前广播ACTION_BOOT_COMPLETED，于是如果应用安装在外置SD卡上，它无法接收到此广播，原文见Broadcast Receivers listening for "boot completed"。

2.从Android 3.1（API level和对应NDK版本）开始，系统的包管理器保持跟踪处于停止状态(stopped state)的应用程序，提供了一种控制其从后台进程和其它应用程序启动的方式。这种停止状态的应用程序指那些安装了但从未启动过的apk，或被用户在程序管理中force stop的apk。Android系统为防止广播无意或不必要开启停止状态的组件，它给所有广播intent添加了FL​​AG_EXCLUDE_STOPPED_PACKAGES标志（不设置和同FLAG_INCLUDE_STOPPED_PACKAGES一起设置结果都是此标志），

Intent.java

public boolean isExcludingStopped() {        return (mFlags&(FLAG_EXCLUDE_STOPPED_PACKAGES|FLAG_INCLUDE_STOPPED_PACKAGES))                == FLAG_EXCLUDE_STOPPED_PACKAGES;    }

IntentResolver.java

/**     * Returns whether the object associated with the given filter is     * "stopped," that is whether it should not be included in the result     * if the intent requests to excluded stopped objects.     */    protected boolean isFilterStopped(F filter, int userId) {        return false;    }private void buildResolveList(Intent intent, FastImmutableArraySet<String> categories,            boolean debug, boolean defaultOnly,            String resolvedType, String scheme, F[] src, List<R> dest, int userId) {        ...        final boolean excludingStopped = intent.isExcludingStopped();        final int N = src != null ? src.length : 0;        boolean hasNonDefaults = false;        int i;        F filter;        for (i=0; i<N && (filter=src[i]) != null; i++) {            int match;            if (debug) Slog.v(TAG, "Matching against filter " + filter);            if (excludingStopped && isFilterStopped(filter, userId)) {                if (debug) {                    Slog.v(TAG, "  Filter's target is stopped; skipping");                }                continue;            }        ...

此标志指广播intent排除停止状态的应用，原文见Launch controls on stopped applications。用户可以给自己的应用或者后台服务添加FLAG_INCLUDE_STOPPED_PACKAGES标志以唤醒停止状态的应用，但系统自带的广播intent，用户无法修改，只能接受；注意系统级应用都不是停止状态。

PackageManagerService.java中重写IntentResolver

final class ActivityIntentResolver            extends IntentResolver<PackageParser.ActivityIntentInfo, ResolveInfo> {        ...@Override        protected boolean isFilterStopped(PackageParser.ActivityIntentInfo filter, int userId) {            if (!sUserManager.exists(userId)) return true;            PackageParser.Package p = filter.activity.owner;            if (p != null) {                PackageSetting ps = (PackageSetting)p.mExtras;                if (ps != null) {                    // System apps are never considered stopped for purposes of                    // filtering, because there may be no way for the user to                    // actually re-launch them.                    return (ps.pkgFlags&ApplicationInfo.FLAG_SYSTEM) == 0                            && ps.getStopped(userId);                }            }            return false;        }private final class ServiceIntentResolver            extends IntentResolver<PackageParser.ServiceIntentInfo, ResolveInfo> {        ...@Override        protected boolean isFilterStopped(PackageParser.ServiceIntentInfo filter, int userId) {            if (!sUserManager.exists(userId)) return true;            PackageParser.Package p = filter.service.owner;            if (p != null) {                PackageSetting ps = (PackageSetting)p.mExtras;                if (ps != null) {                    // System apps are never considered stopped for purposes of                    // filtering, because there may be no way for the user to                    // actually re-launch them.                    return (ps.pkgFlags & ApplicationInfo.FLAG_SYSTEM) == 0                            && ps.getStopped(userId);                }            }            return false;        }