Android 在其他应用之上显示内容的权限是肿么实现的?

一开始就去packagemanager 去看发现有几个方法：就先去看了一下IPackagemanager 里面的方法：有很多 这里我之列出跟权限有关的PermissionInfo getPermissionInfo(String name, int flags); ListPermissionInfo queryPermissionsByGroup(String group, int flags); PermissionGroupInfo getPermissionGroupInfo(String name, int flags); ListPermissionGroupInfo getAllPermissionGroups(int flags); int checkPermission(String permName, String pkgName); int checkUidPermission(String permName, int uid); boolean addPermission(in PermissionInfo info); void removePermission(String name); void grantPermission(String packageName, String permissionName); void revokePermission(String packageName, String permissionName); String[] getAppOpPermissionPackages(String permissionName); ParceledListSlice getPackagesHoldingPermissions(in String[] permissions, int flags, int userId); boolean addPermissionAsync(in PermissionInfo info); void setPermissionEnforced(String permission, boolean enforced);详细