Swift 实践之简单购物(UITableView)

Shopping应用程序

创建一个名为Shopping的工程

描述:通过该练习主要学习UITableView,Storyboard的使用和一些简单的代理传值的学习. 主要实现的是点击保存商品后,会在购物清单中添加刚刚我们新增的产品,选中某行购物清单之后,点击已经购买之后,购物清单相应的商品会变为绿色,已记录我们刚刚的操作.

使用Stroryboard添加相应控件项目目录为:

这里写图片描述 Storyboard结构图如下: 这里写图片描述

代码实现- ViewController的代码实现

// ViewController.swift
// Swift_Shopping
//
// Created by 周文春 on 16/3/7.
// Copyright © 2016年 周文春. All rights reserved.
//import UIKit
class ViewController:UIViewController,UITableViewDataSource,UITableViewDelegate,NewItemViewControllerDelegate { 
@IBOutlet weak var tableView: UITableView!  
//数据源 
var toBuyItems = [ Item(itemName: "牛奶", brandName: "三元"), 
                             Item(itemName: "红烧牛肉面", brandName: "康师傅"), 
                            Item(itemName: "桃汁", brandName: "汇源"), 
                            Item(itemName: "巧克力", brandName: "德芙"), 
                            Item(itemName: "地板净", brandName: "滴露"),
                            Item(itemName: "洗发水", brandName: "飘柔")]  

override func viewDidLoad() {
 super.viewDidLoad() 
// Do any additional setup after loading the view, typically from a nib.
 }  
override func viewWillAppear(animated: Bool) { 
super.viewWillAppear(animated) 
tableView.reloadData()
 }  
//UITableView的两个必须实现的数据源方法 
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int { 
return toBuyItems.count 
}
 func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
 let cell = UITableViewCell(style: UITableViewCellStyle.Subtitle, reuseIdentifier: "cell") 
let item = toBuyItems[indexPath.row] 
if item.isBuy {
 cell.textLabel?.textColor = UIColor.greenColor() 
}else{ 
cell.textLabel?.textColor = UIColor.redColor()
 } 
cell.textLabel?.text = item.itemName 
cell.detailTextLabel?.text = item.brandName 
return cell
 } 
//UITableView的代理方法 
func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
 performSegueWithIdentifier("itemSegue", sender: indexPath.row) 
}  
//通过itemSegue和newItemSegue来标识进入下一个页面 
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) { 
 if segue.identifier == "itemSegue" {
 let destination: ItemViewController = segue.destinationViewController as! ItemViewController 
if sender is Int { 
let item = toBuyItems[sender as! Int] destination.item = item 
} 
}else if segue.identifier == "newItemSegue" {
 let destination: NewItemViewController = segue.destinationViewController as! NewItemViewController 
destination.delegate = self 
}
 }  
//实现NewItemViewController里面的协议方法 
func addNewItem(controller: NewItemViewController, item: Item) {
 //将NewItemViewController里面的实例对象Item加入到数据源toBuyItems中
 toBuyItems.append(item)
 //刷新数据 
tableView.reloadData() 
//销毁NewItemViewController对象 controller.dismissViewControllerAnimated(true, completion: nil)
 }   
override func didReceiveMemoryWarning() { super.didReceiveMemoryWarning() 
// Dispose of any resources that can be recreated. }
}

 NewItemViewController的代码实现

//
// NewItemViewController.swift
// Swift_Shopping
// Created by 周文春 on 16/3/7.
// Copyright © 2016年 周文春. All rights reserved.
import Foundation
import UIKit
//设置代理方法
protocol NewItemViewControllerDelegate {
 func addNewItem(controller: NewItemViewController, item: Item)
}
class NewItemViewController: UIViewController {
  @IBOutlet weak var brandNameTF: UITextField! 
@IBOutlet weak var itemNameTF: UITextField! 
//声明一个Item的实例对象 
var item: Item? 
//声明一个代理
 var delegate: NewItemViewControllerDelegate?
 override func viewDidLoad() { 
super.viewDidLoad() 
}  
@IBAction func saveItem(sender: UIButton) { 
if itemNameTF.text != nil && brandNameTF.text != nil { 
item = Item(itemName: itemNameTF.text!, brandName: brandNameTF.text!) 
}
 if ((delegate) != nil) { 
delegate?.addNewItem(self, item: item!)
 }  
}
 override func didReceiveMemoryWarning() { super.didReceiveMemoryWarning()  }
}

-  ItemViewController的代码实现

//
// ItemViewController.swift
// Swift_Shopping
//
// Created by 周文春 on 16/3/7.
// Copyright © 2016年 周文春. All rights reserved.
//import Foundation
import UIKit
class ItemViewController: UIViewController {  
@IBOutlet weak var brandNameLable: UILabel!
 @IBOutlet weak var itemNameLable: UILabel! 
var item: Item? 
override func viewDidLoad() { 
super.viewDidLoad() 
}  
override func viewWillAppear(animated: Bool) {
  if item != nil {
 itemNameLable.text = item?.itemName 
brandNameLable.text = item?.brandName
 }
 } 
@IBAction func isBuy(sender: UIButton) {
 if item?.isBuy == false { 
item?.isBuy = true
 itemNameLable.textColor = UIColor.greenColor() 
}else{ 
item?.isBuy = false
 itemNameLable.textColor = UIColor.redColor() 
} 
print(item?.description()) 
 } 
override func didReceiveMemoryWarning() { super.didReceiveMemoryWarning()  }
}

  Item文件的代码实现

//
// Item.swift
// Swift_Shopping
//
// Created by 周文春 on 16/3/8.
// Copyright © 2016年 周文春. All rights reserved.
import Foundation
class Item { 
var itemName: String = "" 
var brandName: String = "" 
var isBuy: Bool = false 
 //指定构造器
 init (itemName: String, brandName: String, isBuy: Bool) { self.itemName = itemName 
self.brandName = brandName 
self.isBuy = isBuy 
} 
 //便利构造器 
convenience init (itemName: String) { 
self.init (itemName: itemName, brandName: "", isBuy: false)
 }  
//便利构造器
 convenience init (itemName: String, brandName: String) { 
self.init (itemName: itemName, brandName: brandName, isBuy: false)
 } 
 //Item的描述方法,用于在调试时返回类信息
 func description() -> String {
 return ("itemName: \(itemName) brandName: \(brandName) isBuy: \(isBuy)") 
}
 
 }
### 效果图如下
![这里写图片描述](https://img.haomeiwen.com/i1485325/07152df8add546ac?imageMogr2/auto-orient/strip)