ViewController Lifecycle

• init

• viewDidLoad

  • ViewController default view created
  • Create subviews here, we should put all view related initializations here

• viewWillAppear

  • subView will appear

• viewDidAppear

  • subView did appear

• viewWillDisappear

• viweDidDisappear

UITabBarController

Used to controll Tab bar below

UITabBarController is used to manage (switch between) different ViewControllers

Contains all UIViewControllers needed and a UITabBar

UITabBarController should be created on app launch

• UITabBarController
  • viewControllers
  • UITabBar

Set tabBarItem

viewController1.tabBarItem.title = "";
viewController1.tabBarItem.image = UIImage...;
viewController1.tabBarItem.selectedImage = UIImage...;

UINavigationController

Used to navigate and controll pages

• UINavigationController
  • viewControllers
  • UINavigationBar
    • backIndicatorImage
    • backBarButtonItem
      • image (left side)
      • title(right side)
    • title

Set navigationItem

viewController.navigationItem.title = "";
viewController.navigationItem.titleView = UIView...;
viewController.navigationItem.rightBarButtonItem = UIBarButtonItem...;
//Or 
viewController.navigationItem.rightBarButtonItems = [...];

viewController.navigationItem.leftBarButtonItem = UIBarButtonItem...;
//Or 
viewController.navigationItem.leftBarButtonItem = [...];

UIWindow

If we use storyboard, system will create UIWindow for us

Bottom tab does not change

• UIWindow
  • TabBarController
    • NavigationController1
      • ViewController
    • NavigationController2
      • ViewController

Bottom tab changes

• UIWindow

  • NavigationController

    • TabBarController

      • ViewController1

      • ViewController2

UINavigationController navigationController;

navigationController.initWithRootViewController = tabBarController;

UIWindow window;
window.rootViewController = navigationController;

Delegate

Delegate creater

Offer a user some methods that can be implement

Use @optional/@required annotation to set if methods are optional or required

Offer delegate property

Run the methods in the right time

Delegate user

Set delegate = self to received delegate methods

Implemente needed delegate methods

Used to handle some self defined actions

Es: should switch to a new viewController when clicked tab bar or should I start to play a video in the new viewController after finished tab bar switch,

How to do that?

Set myself as delegate receiver

tabbarController.delegate = self;

Implement the method of tabbar (delegate)

shouldSelectViewController {
	return YES;
}

didSelectViewController {
	//play video
}

UITableView

• UITableView
  • tableHeaderView
  • UITableViewCell
  • tableFooterView

UITableView tableView
view.addSubview(tableview)

Steps:

1. Put Table View in storyboard
2. Link dataSource and delegate to viewController
3. Extends class ViewController: UIViewController, UITableViewDataSource, UITableViewDelegate
4. Implement required methods

Required methods

numberOfRowsInSection -> Int

    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        switch section {
        case 0:
            return dailyTasks.count
        case 1:
            return weeklyTasks.count
        default:
            return 0
        }
    }

cellForRowAtIndexPath -> UITableViewCell

    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = UITableViewCell()
        let rowIndex = indexPath.row
        let sectionIndex = indexPath.section

        switch indexPath.section {
        case 0:
            cell.textLabel?.text = "section \(indexPath.section), row \(rowIndex): \(dailyTasks[rowIndex])"
        case 1:
            cell.textLabel?.text = "section \(sectionIndex), row \(rowIndex): \(weeklyTasks[rowIndex])"
        default:
            cell.textLabel?.text = "default"
        }
        return cell
    }

UIColletionView

UICollectionViewLayout

• UICollecitonViewFlowLayout
  • minimumLineSpacing
  • minimumInteritemSpacing
  • itemSize (CGSizeMake)
  • indexPath

UIScrollView

用于滚动展示 和图片Zoom

滚动展示：左右滑动展示不同板块

frame: scroll view的大小等属性

contentSize：内容大小

contentOffset：展示哪些内容（frame左上角到contentSize左上角的距离xy ）

常用属性

• UIScrollView
  • scrollEnabled
  • pagingEnabled
  • showHorizontalScrollIndicator
  • showVerticalScrollIndicator

常用delegate 方法

scrollViewDidScroll:开始滚动

scrollViewWillBeginDragging：开始拖拽

scrollViewDidEndDragging：结束拖拽

UILabel

• UILabel
  • text
  • font
  • textColor
  • textAlignment
  • numberOfLines
  • lineBreakMode
    • NSLineBreakByClipping 根据宽度暴力截断
    • NSLineBreakByTruncatingMiddle 中间加…
    • NSLineBreakByTruncatingTail 最后加…
    • NSLineBreakByTruncatingHead 前面加…
  • sizeToFit 可变大小

UIImage / UIImageView

UIImageView 展示 UIImage

• UIViewContentMode
  • ToFill 压缩图片到UIImageView的size
  • AspectFit 图片全展示
  • AspectFill 根据UIImageView切原始图片

WKWebView

configuration: Cookie settings; Preference; Allow play video; JS inject ecc

loadRequest(NSURLRequest)

loadHTMLRequest

WKNavigationDelegate

decidePolicyForNavigationAction : 是否加载请求

didFinishNavigation: 完成加载

didFailNavigation：加载失败

webViewWebContentProcessDidTerminate： crash回调（自动从新加载）

WKWebView webView = initWithFrame(CGRect)
addSubview(webView)
webView.loadRequest(NSURLRequest)

Actions and Outlets

outlet

from code to storyboard (label)

Outlet is a property

action

from storyboard to code (if you want user interface element in your storyboard to cause something to happen in your code like button)

Action is a function

IBAction - stand for Interface Builder Action

Add a new view controller (scene)

1. Add View Controller in storyboard
2. Create a new viewController that extends UIViewController
3. Assign the name of new viewController as identity of the new scene
4. Add a segue between two scenes
5. give the new segue an identifier
6. Embed the scene in a navigation controller
   1. Click the first View Controller in the storyboard
   2. Editer->Embed in -> Navigation controller

Auto Layout

Ctrl + Drag left on element: Center Horizontally in Safe Area

Stack View

Select multi elements -> Editor -> Embed in -> Stack View

Key words

Weak

Weak means we have only the ref of this object, we do not create it, do not control its lifecycle

Xcode tips

Suggestion:

Holding Option Key, then move mouse to where you want to get help

Note

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