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
存取照相機的 API 在 OS X 與 iOS 上並不相同。照相機在 iOS 釋出之前早就已經由 Mac
引進，iOS 的實作稍微容易使用且簡潔俐落些，因為它的 API 受益於幾年下來所累積的
開發經驗。
如果你真的需要跨 iOS 與 OS X 一致的視頻攝製 API，AV Foundation 有
提供一組類別讓你拍攝內容，包括
AVCaptureSession
、
AVCaptureInput
和
AVCaptureOutput
等關鍵類別。然而，這個系統被設計來針對由相機到
終端使用者的資料流（data flow）做更細微的控制，而不只是像錄製視頻
及將它儲存成檔案那樣簡單的用途。因此，在這一章中，我們只會說明
iOS 實作的部分，OS X 開發者請參考Xcode 文件說明裡的〈
QTKit
Application Tutorial
〉。
以相機拍攝照片與視頻
要從 iOS 上的相機拍攝視頻和照片，你使用稱作
UIImagePickerController
的視圖
控制器。
欲瞭解更多視圖控制器的相關資訊，請參見〈nib 檔的結構〉（第 75 頁 ）。
從最簡單來看，
UIImagePickerController
讓你呈現幾乎與 iPhone 和 iPad 內建相機應用
程式完全一樣的介面，透過這個介面，使用者可以拍攝照片，並且將它以
UIImage
物件
的形式傳送給你的應用程式。
你也能夠組態
UIImagePickerController
進行視頻拍攝，在這種情況下，使用者能夠錄
製長達 30 分鐘的視頻，並且透過 ...
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O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
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.