如果你想避开快门声，你必须使用 AVCaptureVideoDataOutput 。请注意，隐蔽捕获图像是针对App Store策略的。您需要确保以某种方式告诉用户您拍照。

You have to use an AVCaptureVideoDataOutput if you want to avoid the shutter sound. Note that covertly capturing images is against App Store policy. You need to make sure you user is told in some way that your taking a picture.