ios - 针对 iOS 6+ 时是否需要检查相机是否存在？

Question

我正在制作一个在多个区域使用摄像头的应用程序，我突然想到所有支持 iOS 6+ 的设备都有一个摄像头。这更像是一个编程实践问题，而不是一个实际的实现问题。

Apple 从未明确建议您检查摄像头，但许多开发人员会这样做。

不检查安全吗？ 不检查摄像头有什么影响？

有什么性能优势/劣势吗？

谢谢，

维林德博拉

Answer 1

来自 UIImagePickerController isSourceTypeAvailable: 方法的文档:

Because a media source may not be present or may be unavailable, devices may not always support all source types. For example, if you attempt to pick an image from the user’s library and the library is empty, this method returns NO. Similarly, if the camera is already in use, this method returns NO.

Before attempting to use an UIImagePickerController object to pick an image, you must call this method to ensure that the desired source type is available.

所以是的，Apple 确实会告诉您进行检查。再说，做起来有多难:

if ([UIImagePickerController isSourceTypeAvailable: UIImagePickerControllerSourceTypeCamera]) {
    // show camera
} else {
    // don't show camera
}