App Programming Guide for iOS翻译
https://developer.apple.com/library/content/documentation/iPhone/Conceptual/iPhoneOSProgrammingGuide/Introduction/Introduction.html
About iOS App Architecture
译：关于iOS App架构
Apps need to work with the iOS to ensure that they deliver a great user experience. Beyond just a good design for your app’s design and user interface, a great user experience encompasses many other factors. Users expect iOS apps to be fast and responsive while expecting the app to use as little power as possible. Apps need to support all of the latest iOS devices while still appearing as if the app was tailored for the current device. Implementing all of these behaviors can seem daunting at first but iOS provides the help you need to make it happen.
译：确保运行在iOS系统上的App能提供给用户非常好的用户体验。不仅仅只为应用程序和UI设计，一个好的用户体验包含其他好几种因素。用户所期待的iOS App应该是快速响应且消耗更小的电量。App必须支持最新的iOS设备，即使是为现在的设备所定做的。应用程序需要支持所有最新的iOS设备同时出现,如果应用程序是针对当前的设备。实现所有这些行为起初似乎令人生畏,但iOS系统提供您所需要的帮助。
This document highlights the core behaviors that make your app work well on iOS. You might not implement every feature described in this document but you should consider these features for every project you create.
译：本文档所强调核心行为能让你的App更好地运行在iOS系统上。你不需要实现所有本文档描述的行为，但是每一个项目你都应该去考虑这些功能。
Note: Development of iOS apps requires an Intel-based Macintosh computer with the iOS SDK installed. For information about how to get the iOS SDK, go to the iOS Dev Center.
不直译：iOS App开发需要一台IntelCPU的Mac，并且安装了Xcode。
At a Glance
译：概览
When you are ready to take your ideas and turn them into an app, you need to understand the interactions that occur between the system and your app.
译：当你准备好将你的构想转化为App时，你需要去了解iOS系统与App之间的相互作用关系。
Apps Are Expected to Support Key Features
译：App所希望支持的主要特性
The system expects every app to have some specific resources and configuration data, such as an app icon and information about the capabilities of the app. Xcode provides some information with every new project but you must supply resource files and you must make sure the information in your project is correct before submitting your app.
译：iOS系统预计每个应用都有一些特殊的资源和配置数据,例如应用程序的图标和关于app功能信息。Xcode为每一个新的工程配置了一些信息,但在上传你的app到应用商店之前，你必须提供相关的资源文件和确保你项目中的信息是正确的。
Relevant Chapter: Expected App Behaviors
相关章节：Expected App Behaviors （应用程序行为期望)
Apps Follow Well-Defined Execution Paths
译：Apps遵循良好的执行路径
From the time the user launches an app to the time it quits, apps follow a well-defined execution path. During the life of an app, it can transition between foreground and background execution, it can be terminated and relaunched, and it can go to sleep temporarily. Each time it transitions to a new state, the expectations for the app change. A foreground app can do almost anything but background apps must do as little as possible. You use the state transitions to adjust your app’s behaviors accordingly.
译：应用程序App从用户启动开始到它终止退出,它遵循了良好的执行路径。在整个应用程序生命周期里,它可以在前台和后台之间的相互过渡执行,它可以被终止和重新启动,它可以暂时去休眠。每次过渡到一个新的状态,应用程序的预计行为会发生变化。应用程序在前台时可以做几乎任何事情但在后台时必须尽可能少做事情。请您使用这些状态过渡相应地调整你的应用程序行为。
Relevant Chapter: The App Life Cycle, Strategies for Handling App State Transitions
相关章节：The App Life Cycle, Strategies for Handling App State Transitions （App生命周期，处理App状态过渡的策略）
Apps Must Run Efficiently in a Multitasking Environment
译：应用程序必须有效地运行在一个多任务环境中
Battery life is important for users, as is performance, responsiveness, and a great user experience. Minimizing your app’s usage of the battery ensures that the user can run your app all day without having to recharge the device, but launching and being ready to run quickly are also important. The iOS multitasking implementation offers good battery life without sacrificing the responsiveness and user experience that users expect, but the implementation requires apps to adopt system-provided behaviors.
译：电池寿命对于用户来说是很重要的,关乎到性能、响应性、好的用户体验。让你的app电量消耗最小化确保用户可以整天使用您的应用程序一整天而无需充电,但迅速启动和运行速度也很重要。iOS系统多任务的实现提供了良好的电池寿命且不牺牲用户所期望的响应性和用户体验,但是想要实现这些效果，要求应用程序采用系统提供的行为。
Relevant Chapters: Background Execution, Strategies for Handling App State Transitions
相关章节：Background Execution, Strategies for Handling App State Transitions （后台执行，处理App状态过渡的策略）
Communication Between Apps Follows Specific Pathways
译：App间通讯必须通过特殊通道
For security, iOS apps run in a sandbox and have limited interactions with other apps. When you want to communicate with other apps on the system, there are specific ways to do so.
译：为了安全,iOS应用程序运行在沙箱里，并提供有限的与其他应用程序交互方式。当你想要与系统上其他应用程序通信,有特定的方式去访问。
Relevant Chapter: Inter-App Communication
相关章节：Inter-App Communication （App之间相互通讯）
Performance Tuning is Important for Apps
译：性能优化App重要性
Every task performed by an app has a power cost associated with it. Apps that drain the user’s battery create a negative user experience and are more likely to be deleted than those that appear to run for days on a single charge. So be aware of the cost of different operations and take advantage of power-saving measures offered by the system.
译：每一个由应用程序处理的任务都会有电量消耗。App消耗电池电量都会给用户体验性造成负面的影响，比起那些能够运行好几天才充一次电的应用，它更容易给用户删除掉。所以要充分意识到不同操作的耗电量和充分利用系统提供的省电措施。
Relevant Chapter: Performance Tips
相关章节：Performance Tips （性能优化技巧）
How to Use This Document
译：如何使用本文档
This document is not a beginner’s guide to creating iOS apps. It is for developers who are ready to polish their app before putting it in the App Store. Use this document as a guide to understanding how your app interacts with the system and what it must do to make those interactions happen smoothly.
译：这个文档不是一个初学者创建iOS应用程序指南。这是为开发人员上传App到app Store之前的一系列改进。使用本文档作为了解应用程序与系统相互作用的指南,它指出了必须做些什么来实现这些交互更加顺畅。
Prerequisites
译：预备知识
This document provides detailed information about iOS app architecture and shows you how to implement many app-level features. This book assumes that you have already installed the iOS SDK, configured your development environment, and understand the basics of creating and implementing an app in Xcode.
译：本文档提供了iOS应用程序体系结构详细信息和向您展示如何实现应用程序水平的特性。这本书假设您已经安装了iOS SDK,配置开发环境,懂得在Xcode中基本创建和实现一个应用程序。
If you are new to iOS app development, read Start Developing iOS Apps (Swift). That document offers a step-by-step introduction to the development process to help you get up to speed quickly. It also includes a hands-on tutorial that walks you through the app-creation process from start to finish, showing you how to create a simple app and get it running quickly.
译：如果你是iOS应用程序开发者新手,请阅读Start Developing iOS Apps (Swift)。该文档提供了一个循序渐进的开发过程介绍来帮助你迅速成长，它还包括一个从头到尾创建一个app实践教程展示如何创建一个简单的App和让它快速运行。
See Also
译：阅读推荐
If you are learning about iOS, read iOS Technology Overview to learn about the technologies and features you can incorporate into your iOS apps.
译：如果你正在学习iOS开发，请阅读iOS Technology Overview文档，学习iOS相关技术和功能并添加到你的iOS应用程序中。