|= 和 &= ~

private int mFlags;

    public void setUserFixed(boolean userFixed) {
        if (userFixed) {
            mFlags |= PackageManager.FLAG_PERMISSION_USER_FIXED;
        } else {
            mFlags &= ~PackageManager.FLAG_PERMISSION_USER_FIXED;
        }
    }

    public boolean isSystemFixed() {
        return (mFlags & PackageManager.FLAG_PERMISSION_SYSTEM_FIXED) != 0;
    }