Android应用没有Activity是否可以接受广播?

一个应用没有activity，在API<3.1的版本是可以的接受广播，3.1以后就不可以了。

从3.1开始出于安全的考虑，一个应用必须至少运行一次才能接受广播，意思是说用户知道这个应用运行过，它才可以接受广播。如果非要试试没有activity的话，可以第一次安装有activity，然后，删除activity和xml对应的配置信息再次安装。不过这样实际意义不大。

普通的App如果没有启动默认都是停止状态的，停止状态的App默认是接受不到任何广播的。不过发送广播时如果添加指定标记，也可以使停止状态的应用接受这个的广播。

/**
 * If set, this intent will not match any components in packages that
 * are currently stopped.  If this is not set, then the default behavior
 * is to include such applications in the result.
 */
public static final int FLAG_EXCLUDE_STOPPED_PACKAGES = 0x00000010;
/**
 * If set, this intent will always match any components in packages that
 * are currently stopped.  This is the default behavior when
 * {@link# FLAG_EXCLUDE_STOPPED_PACKAGES} is not set.  If both of these
 * flags are set, this one wins (it allows overriding of exclude for
 * places where the framework may automatically set the exclude flag).
 */
public static final int FLAG_INCLUDE_STOPPED_PACKAGES = 0x00000020;

以上是相关的intent的flag设置。注释已经说的很清楚了，FLAG_INCLUDE_STOPPED_PACKAGES是默认行为，如果2个标记都设置的话，也是这个标记主导：停止状态的应用也能接受发送的广播。但是上面已经描述过了：

手头最新的系统源码4.2的，找到了相关设置，在以下文件中：

frameworks/base/services/java/com/android/server/pm/PackageManagerService.java

/**
 * If set, this intent will not match any components in packages that
 * are currently stopped.  If this is not set, then the default behavior
 * is to include such applications in the result.
 */
public static final int FLAG_EXCLUDE_STOPPED_PACKAGES = 0x00000010;
/**
 * If set, this intent will always match any components in packages that
 * are currently stopped.  This is the default behavior when
 * {@link# FLAG_EXCLUDE_STOPPED_PACKAGES} is not set.  If both of these
 * flags are set, this one wins (it allows overriding of exclude for
 * places where the framework may automatically set the exclude flag).
 */
public static final int FLAG_INCLUDE_STOPPED_PACKAGES = 0x00000020;

广播默认不会发给停止状态的应用，除非设置过FLAG_INCLUDE_STOPPED_PACKAGES标记，但是系统（保守说大多数）广播是没有设置这个标记的，也就是说停止状态系统的应用接受不到系统广播。普通应用自定义的广播可以随便设置标记。

/**
 * If set, this intent will not match any components in packages that
 * are currently stopped.  If this is not set, then the default behavior
 * is to include such applications in the result.
 */
public static final int FLAG_EXCLUDE_STOPPED_PACKAGES = 0x00000010;
/**
 * If set, this intent will always match any components in packages that
 * are currently stopped.  This is the default behavior when
 * {@link# FLAG_EXCLUDE_STOPPED_PACKAGES} is not set.  If both of these
 * flags are set, this one wins (it allows overriding of exclude for
 * places where the framework may automatically set the exclude flag).
 */
public static final int FLAG_INCLUDE_STOPPED_PACKAGES = 0x00000020;