pod：查詢cocoaPods的使用方法
pod search XXX
pod init：先要初始化文件贼急，使文件產生Podfile文件
pod install： 更新
重要方法：SnapKit摔刁、PINRemoteImage布卡、SDWebImage拖吼、Kingfisher换淆、SwiftyJSON地技、Alamofire
顏色: ColorPicker
類型轉換: ObjectMapper

let imageView = UIImageView()
        self.view.addSubview(imageView)
        
        imageView.snp.makeConstraints { (make) in
            make.centerX.centerY.equalTo(self.view)
            make.width.height.equalTo(200)
        }
        
        let url = NSURL(string: "http://s1.dwstatic.com/group1/M00/69/44/c0e5bff6974446bb9cd5bec040393a03.gif")
//        imageView.pin_setImageFromURL(url)
        imageView.pin_setImageFromURL(url, placeholderImage: UIImage(named: "cat.jpg"))
//        imageView.startAnimating()
        
        print(NSHomeDirectory())
        
        
//        self.view.translatesAutoresizingMaskIntoConstraints = false
        
        redView = UIView()
        redView.backgroundColor = UIColor.redColor()
        self.view.addSubview(redView)
        
//        redView.snp_makeConstraints { (make) in
//            make.right.equalTo(self.view.snp_right)
//            make.bottom.equalTo(self.view.snp_bottom)
//            make.width.equalTo(100)
//            make.height.equalTo(100)
//        }
        
//        redView.snp.makeConstraints { (make) in
//            make.right.equalTo(self.view.snp.right)
//            make.bottom.equalTo(self.view.snp.bottom)
//            make.size.equalTo(CGSize(width: 100, height: 100))
//        }
        //UIEdgeInsets
        redView.snp.makeConstraints { (make) in
//            make.right.equalTo(self.view)
//            make.bottom.equalTo(self.view)
            make.right.bottom.equalTo(self.view)
//            make.size.equalTo(CGSize(width: 100, height: 100))
            make.width.height.equalTo(self.view).multipliedBy(0.2)

        }
        
//        let width = self.view.frame.size.width
//        let height = self.view.frame.size.height
//        redView.frame = CGRect(x: width - 100, y: height - 100, width: 100, height: 100)
        
        let greenView = UIView()
        greenView.backgroundColor = UIColor.greenColor()
        self.view.addSubview(greenView)
        
        greenView.snp.makeConstraints { (make) in
//            make.top.left.equalTo(redView).offset(20)
            //make.width = redView.width * 0.5
            make.width.height.equalTo(redView).multipliedBy(0.5)
            make.centerX.centerY.equalTo(redView)
        }



//如果一個視圖是通過自動布局設置的位置和大小朗鸠，以后不應該直接修改它的frame，而需要更新(重新設置)約束
    override func touchesBegan(touches: Set<UITouch>, withEvent event: UIEvent?) {
        //更新約束
        redView.snp.updateConstraints { (make) in
//            make.size.equalTo(CGSize(width: 300, height: 300))
            make.size.equalTo(self.view).multipliedBy(0.5)
        }
        
        //重新設置視圖的約束，會將老的約束全部清除
//        redView.snp.remakeConstraints { (make) in
//            make.size.equalTo(CGSize(width: 200, height: 200))
//        }
    }


        //使用SwiftyJSON解析數據
        let json: JSON = JSON(data: data!)
        print(json[0]["title"].string!)
        print(json[0]["price"].float!)
        print(json[2, "price"].float!)
        //轉換成json類型
        let ja = JSON(bookArray!)
        print(ja.rawString()!)

            //1. 下載數據
            //2. 解析數據
            //3. 切換到主線程
            Alamofire.request(.GET, "http://go.class.room/city?areacode=0101").responseJSON { (response) in
            if response.result.error == nil {
                let result = response.result.value
                print(result)
                
                print(NSThread.isMainThread())
            }
        }

tableView的有關使用

func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
        //只負責重用
        var cell = tableView.dequeueReusableCellWithIdentifier("cell")
        
//        var imageView: UIImageView! //變量必須賦值以后才能使用
        if cell == nil {
            //如果剛創(chuàng)建，肯定是第一次使用
            cell = UITableViewCell(style: .Default, reuseIdentifier: "cell")
            
            let imageView = UIImageView()
            imageView.frame = CGRect(x: 10, y: 10, width: 50, height: 60)
            imageView.tag = 1001 //默認為0
            cell!.contentView.addSubview(imageView)
        }
        
        //1. 作用域 2. 賦值
        let dict = bookArray![indexPath.row]
        let path = dict["cover"] as! String
        
        let imageView = cell!.viewWithTag(1001) as? UIImageView //根據tag值查找子視圖(UIView)
        imageView!.kf_setImageWithURL(NSURL(string: path))

        return cell!
    }



    //切換到主線程
dispatch_async(dispatch_get_main_queue(), { 
                                    self.tableView2.reloadData()
                                })