[iOS]Start Developing iOS Apps (Swift)- 学习笔记

• 官方入门教程
  已经看完一遍了。学习耗时大概在5～6小时

Main Topic

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XCode工具描述

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• Navigator area(导航区域)
  此区域包含代码目录结构、类结构、搜索代码、build信息、debug断点等
• Toolbar(工具栏)
  一些模拟器信息现在在这个区域
• Editor area(编辑区域)
  代码、ui编辑区域
• Utility area(属性工具区域)
  不同文件会有不同属性

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核心文件基本说明

• AppDelegate
  • 创建App window详细描述见下面
    It defines your AppDelegate class. The app delegate creates the window where your app’s content is drawn and provides a place to respond to state transitions within the app.
  • App入口类，提供一个run loop监控用户输入
    It creates the entry point to your app and a run loop that delivers input events to your app. This work is done by the UIApplicationMain attribute (@UIApplicationMain), which appears toward the top of the file.
• ViewController
  从UIViewController继承下来的class，主要定义UI行为。
  • lifecycle后续补充
• Storyboard(场景)
  这个文件类型，定义UI页面（类似android的xml定义ui展示，不过功能更加强大）
  • Canvas（幕布）
    场景(页面)可以定义在这里面
  • Scene
    理解成一个页面或场景。可以在里面添加各种UI组件，Navi行为等
    • 添加方法（choose View > Utilities > Show Object Library，选择一个control，拖拽到canvas空白区域就可以创建一个Scene）

    • 一个Scene对应一个Control源码（这是iOS VM设计模式），可以自己选择相应的ViewControl代码

      
      
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    • Outlets
      将Scene与source code关联起来
    • Action
      将Scene里面的组件的行为和代码关联起来
    • Navi
      定义页面跳转行为
    • Delegate
      处理用户输入。通过代理类方式例如：UITextFieldDelegate
• Assets.xcassets
  • 定义图片资源
    link
• Info.plist
  • 定义权限，项目配置等
• ViewController
  基类是UIViewController,基本上所有ViewController都是从它继承而来，在里面初始一个Scene的基本展示流程。

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* viewDidLoad()—Called when the view controller’s content view (the top of its view hierarchy) is created and loaded from a storyboard. 
* viewWillAppear()—Called just before the view controller’s content view is added to the app’s view hierarchy. 
* viewDidAppear()—Called just after the view controller’s content view has been added to the app’s view hierarchy.
* viewWillDisappear()—Called just before the view controller’s content view is removed from the app’s view hierarchy.
* viewDidDisappear()—Called just after the view controller’s content view has been removed from the app’s view hierarchy.

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基本内容

• Custom Control
  link
  • 定义View代码文件，基类UIView
    重写一些核心方法，一些logic处理
  • CustomView显示UI
    • storyboard里面定义view
    • 绑定viewcode，在Identity inspector里面关联相应的View代码。

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• Navigation
  页面跳转
  • Navigation Controller
    • 添加 Choose Editor > Embed In > Navigation Controller.
    • 修改Navigation Bar
      可以修改名字，导航button等
  • Segue
    • 页面跳转模式(Push\Modal\Custom)
    • 处理segue的方法
      override func prepare(for segue: UIStoryboardSegue, sender: Any?)处理Segue事件
      segue.destination可以找到目标对象Viewcontrol进行数据传输
• Persist Data(数据持久化)
  • NSCoding方案
    • 建立PropertyKey
    • 持久化路径
      static let DocumentsDirectory = FileManager().urls(for: .documentDirectory, in: .userDomainMask).first!
      static let ArchiveURL = DocumentsDirectory.appendingPathComponent("meals")
    • 编解码
      encode(with aCoder: NSCoder)／init?(coder aDecoder: NSCoder)
    • 保存NSKeyedArchiver.archiveRootObject(meals, toFile: Meal.ArchiveURL.path)
    • 读取NSKeyedUnarchiver.unarchiveObject(withFile: Meal.ArchiveURL.path) as? [Meal]