June 2013
Intermediate to advanced
360 pages
6h 50m
Chinese
Content preview from COCOA學習手冊--使用OBJECTIVE-C第三版
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第八章
你可以進一步指明是否有前置或後置相機可用，使用
isCameraDeviceAvailable:
類別
方法︰
if ([UIImagePickerController
isCameraDeviceAvailable:UIImagePickerControllerCameraDeviceFront]) {
// 有前置相機可用
}
if ([UIImagePickerController
isCameraDeviceAvailable:UIImagePickerControllerCameraDeviceRear) {
// 有後置相機可用
}
iOS 模擬器沒有照相機，而且
UIImagePickerController
會報告這項事
實。如果你想要測試照相機的使用，你必須在內建照相機的實際裝置上測
試你的 App。這不會阻止你使用
UIImagePickerController
本身，因為你
仍然可以存取使用者所儲存的照片庫。我們會在下一節裡更仔細地談論這
件事。
建構 Photos 應用程式
為了示範如何使用
UIImagePickerController
，我們將打造一支讓使用者拍照，然後將
照片顯示在螢幕上的簡單應用程式。圖像擷取器會被組態成只拍攝照片，並且在有前置
相機可用時使用前置相機，在沒有前置相機可用時使用後置相機。
1.
建立應用程式
。建立單視圖 iPhone 應用程式，並將之命名為
Photos
。
這支應用程式的介面被特意設計得很簡單︰帶出相機視圖的按鈕，以及展示使用者所
拍攝之照片的圖像視圖。 ...
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I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
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I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.