一個簡單的清單 demo

本 demo 特色功能：

1. Navigation Item Large Title
2. 多個視圖繼承自定義的 SwipeTableViewController (使用 SwipeCellKit 封裝的可編輯 TableView)
3. realm 緩存數據到本地
4. 模糊搜索
5. 動態 cell 背景色優化
6. navigationBar 背景色優化
7. ChameleonFramework （變色龍Framework）使用

主要代碼：

功能2：

SwipeTableViewController：

import UIKit
import SwipeCellKit

class SwipeTableViewController: UITableViewController, SwipeTableViewCellDelegate {
    
    var cell: UITableViewCell?

    override func viewDidLoad() {
        super.viewDidLoad()
        tableView.rowHeight = 80.0
    }

    // TableView Datasource Methods
    override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        
        let cell = tableView.dequeueReusableCell(withIdentifier: "Cell", for: indexPath) as! SwipeTableViewCell
        cell.delegate = self
        return cell
    }

    func tableView(_ tableView: UITableView, editActionsForRowAt indexPath: IndexPath, for orientation: SwipeActionsOrientation) -> [SwipeAction]? {
        
        guard orientation == .right else { return nil }
        let deleteAction = SwipeAction(style: .destructive, title: "Delete") { action, indexPath in
            // handle action by updating model with deletion
            self.updateModel(at: indexPath)
        }
        
        // customize the action appearance
        deleteAction.image = UIImage(named: "delete-icon")
        return [deleteAction]
    }
    
    func tableView(_ tableView: UITableView, editActionsOptionsForRowAt indexPath: IndexPath, for orientation: SwipeActionsOrientation) -> SwipeTableOptions {
        var options = SwipeTableOptions()
        options.expansionStyle = .destructive
        return options
    }
    
    func updateModel(at indexPath: IndexPath) {
        // Update our data model.
        print("Item deleted from superclass")
    }

}

功能4：

extension TodoListViewController: UISearchBarDelegate {
    
    func searchBarSearchButtonClicked(_ searchBar: UISearchBar) {
        todoItems = todoItems?.filter("title CONTAINS[cd] %@", searchBar.text!).sorted(byKeyPath: "dateCreated", ascending: true)
        tableView.reloadData()
    }
    
    
    func searchBar(_ searchBar: UISearchBar, textDidChange searchText: String) {
        if searchBar.text?.count == 0 {
            loadItems()
            DispatchQueue.main.async {
                searchBar.resignFirstResponder()
            }
        }
    }
}

功能6：

func updateNavBar(withHexCode colourHexCode: String){
        
        guard let navBar = navigationController?.navigationBar else {fatalError("Navigation controller does not exist.")}
        guard let navBarColour = UIColor(hexString: colourHexCode) else { fatalError()}
        navBar.barTintColor = navBarColour
        navBar.tintColor = ContrastColorOf(navBarColour, returnFlat: true)
        navBar.largeTitleTextAttributes = [NSAttributedString.Key.foregroundColor : ContrastColorOf(navBarColour, returnFlat: true)]
        searchBar.barTintColor = navBarColour
        
    }

功能7：

navBar.tintColor = ContrastColorOf(navBarColour, returnFlat: true)

方法 ContrastColorOf() 作用是根據背景色生成相應的黑色或白色。本例中 navBar 字體顏色根據 navBarColour 背景色的不同而生成或白或黑的顏色，提高視覺體驗。比如背景色爲黑色的時候，字體顯示爲白色，背景色爲白色的時候，字體顯示爲黑色。

ContrastColorOf 方法具體註釋：

Creates and returns either a black or white color object depending on which contrasts more with a specified color.
 
 - parameter backgroundColor: The specified color of the contrast color that is being requested.
 - parameter returnFlat:      Pass **true** to return flat color objects.
 
 - returns: A UIColor object in the HSB colorspace.

demo下載

參考：

1. Chameleon
2. Chameleon——輕量級 iOS 顏色框架