如何在android中验证签名板是否为空？

public boolean isSignatureEmpty(Context context) {
    try {
        PackageManager packageManager = context.getPackageManager();
        String packageName = context.getPackageName();
        PackageInfo packageInfo = packageManager.getPackageInfo(packageName, PackageManager.GET_SIGNATURES);
        Signature[] signatures = packageInfo.signatures;
        return (signatures == null || signatures.length == 0);
    } catch (PackageManager.NameNotFoundException e) {
        e.printStackTrace();
        return false;
    }
}