[iOS] 使用UIRefreshControl 实现 UITableView下拉刷新（Swift版本）

首先，在viewDidLoad中初始化相关数据：

  override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view.
        
        //添加刷新
        refreshControl.addTarget(self, action: "refreshData", forControlEvents: UIControlEvents.ValueChanged)
        refreshControl.attributedTitle = NSAttributedString(string: "松手刷新新闻")
        newsTableView.addSubview(refreshControl)
        
    }

接下来把Selector 完善一下，添加refreshData方法：

 // 刷新数据
    func refreshData() {
        let bquery = BmobQuery(className: "News")
        bquery.findObjectsInBackgroundWithBlock({array, error in
            self.dataArray = array
            self.newsTableView.reloadData()
            self.refreshControl.endRefreshing()
        })
    }

完整的代码如下，因为涉及到 BMOB API 的调用，所以有些代码可能看不懂，但是并不影响基本功能的使用。

//
//  NewsViewController.swift
//  WomenWorkerGuide
//
//  Created by why on 9/20/14.
//  Copyright (c) 2014 why. All rights reserved.
//

import UIKit

/**
*  新闻
*/
class NewsViewController: UIViewController,UITableViewDelegate,UITableViewDataSource {

    @IBOutlet weak var newsTableView: UITableView!
    
    var refreshControl = UIRefreshControl()
    
    var dataArray:[AnyObject] = [AnyObject]()
    
    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view.
        self.automaticallyAdjustsScrollViewInsets = false
        
        //添加刷新
        refreshControl.addTarget(self, action: "refreshData", forControlEvents: UIControlEvents.ValueChanged)
        refreshControl.attributedTitle = NSAttributedString(string: "松开后自动刷新")
        newsTableView.addSubview(refreshControl)
        refreshData()
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }
    
    // 刷新数据
    func refreshData() {
        let bquery = BmobQuery(className: "News")
        bquery.findObjectsInBackgroundWithBlock({array, error in
            self.dataArray = array
            self.newsTableView.reloadData()
            self.refreshControl.endRefreshing()
        })
    }

    // MARK: - UITableViewDataSource
    func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return dataArray.count;
    }
    
    func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
        
        let cell = UITableViewCell(style: UITableViewCellStyle.Subtitle, reuseIdentifier: "newsCell")
        
        let obj: BmobObject = dataArray[indexPath.row] as BmobObject
   
        cell.textLabel?.text = obj.objectForKey("title") as? String
       
        
        let dateFormatter = NSDateFormatter()
        dateFormatter.dateFormat = "yyyy年 MM月 dd日"
        let str = dateFormatter.stringFromDate(obj.createdAt)
        cell.detailTextLabel?.text = str
        return cell;
    }
    
    
    
    
    /*
    // MARK: - Navigation

    // In a storyboard-based application, you will often want to do a little preparation before navigation
    override func prepareForSegue(segue: UIStoryboardSegue!, sender: AnyObject!) {
        // Get the new view controller using segue.destinationViewController.
        // Pass the selected object to the new view controller.
    }
    */

}