iOS APP Develop Cheat Sheet

2016-07-21 新增使用程式碼刻UI元件
2016-07-22 新增使用segue
2016-08-10 新增Switch button和Segmented Control, 修改segue用法
*2016-08-23 新增UIPickerView和UISearchController

UITableView:

1. ViewController 需要繼承UITableViewDataSource, UITableViewDelegate
2. 加入func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {}
3. 加入func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {}

4. 上一個步驟中，使用tableView.dequeueReusableCellWithIdentifier(cellIdentifier, forIndexPath: indexPath)設定cell (cell要設定identifier)

5. 最後，選取TableView，按住ctrl拖曳至View Controller並選取dataSource和delegate

額外設定：

1. 修改section title

override func tableView(tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
    return "Section \(section)"
}

使用程式碼新增UI元件

以UIImageView為例

let image = UIImageView()

override func viewDidLayoutSubviews() {
  view.addSubview(image)
  image.translatesAutoresizingMaskIntoConstraints = false
  NSLayoutConstraint.activateConstraints([
    artwork.topAnchor.constraintEqualToAnchor(view.topAnchor),
    artwork.bottomAnchor.constraintEqualToAnchor(view.bottomAnchor),
    artwork.rightAnchor.constraintEqualToAnchor(view.rightAnchor),
    artwork.leftAnchor.constraintEqualToAnchor(view.leftAnchor)
  ])
}

使用segue

在storyboard建立segue後。在Attribute inspector中，修改Identifier（例如命名為showMessageIdentifier)，假如轉換到名為ImageViewController的ViewController

然後在view controller加入以下程式碼

override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
  if segue.identifier == "showMessageIdentifier" {
    let vc = segue.destinationViewController as! ImageViewController           
    //  do something
  }
}

使用Switch Button

if switchButton.on {
  // do something
} else {
  // do something
}

使用Segmented Control

可用selectedSegmentIndex判斷目前的選擇

switch locationSegmentedControl.selectedSegmentIndex {
  // do something
}

UIPickerView

1. 拉UIPickerView的outlet至ViewController
2. 設定並實作delegate及dataSource

class ViewController: UIViewController {

    @IBOutlet weak var locationPicker: UIPickerView!
    
    var taipeiDistrictArray = ["中正區", "中山區"]
    
    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
      
        locationPicker.delegate = self
        locationPicker.dataSource = self
    }

}

// MARK: UIPickerViewDataSource
extension ViewController: UIPickerViewDataSource {
    func numberOfComponentsInPickerView(pickerView: UIPickerView) -> Int {
        return 1
    }
    
    func pickerView(pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
        return taipeiDistrictArray.count
    }
}

// MARK: UIPickerViewDelegate
extension ViewController: UIPickerViewDelegate {
    func pickerView(pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
        return taipeiDistrictArray[row]
    }
}

參考來源：
iOS & Swift Tutorial: UITableViewController