/*
        let apples = 3
        let orange = 5
        let L = 1.1
        let appleSummary = "I have \(apples) apples"
        let fruitSummary = "I have \(apples + orange) pieces of fruit."
        let isay = "I Love \(L) you "
        print(isay)
        let expliciFloat: Float = 4
//        print(fruitSummary)
        print(expliciFloat)
        let label = "label"
        let width = 94
        let widthlabel = label + String(width)
        print(widthlabel)
        */
        /*初始化一个数组有值数组*/
        var shoppingList = ["catfish","water","tulips","agg","water"]
        var dic = [
            "A":"a",
            "B":"b",
        ]
        shoppingList[1] = "aaaaaa"
//        print(shoppingList[0])
        /*初始化一个空的数组和字典*/
//        let emptyArray = String["",""]()
         let emptyDictionary = Dictionary<String, Float >()
        print(emptyDictionary)
        let textLabel = UILabel (frame:CGRectMake(self.view.frame.size.width/8,20,self.view.frame.size.width*3/4,100))
//        给label 设值
        textLabel.text = "现在我们来开始学习如何创建我们的第一个swift控件吧 -UILabel"
//        设置是否默认换行
        textLabel.numberOfLines = 0
//        设置label的背景颜色
        var whitColor = UIColor(red:1.0,green:1.0,blue:1.0,alpha:1.0)
        textLabel.backgroundColor = whitColor
        self.view.addSubview(textLabel)
        //view
        let view  = UIView (frame: CGRectMake(100, 100, 100, 100))
        view.backgroundColor = UIColor.blueColor()
        self.view.addSubview(view)
        //textfield
        let textfield = UITextField(frame: CGRectMake(20, 200, 200, 50))
        textfield.text = "哈哈"
        textfield.textColor = UIColor.redColor()
        self.view.addSubview(textfield)
        //button
        let button = UIButton(frame: CGRectMake( 20, 250, 150, 30))
        button.backgroundColor = UIColor.purpleColor()
        button.titleLabel?.text = "1111"
        button.addTarget(self, action:Selector("buttonClick:")  , forControlEvents: UIControlEvents.TouchUpInside)
        self.view.addSubview(button)
        //imageview
        let imageview = UIImageView (frame: CGRectMake(20, 300, 300, 300))
        imageview.image = UIImage(named: "Unknown")
        self.view.addSubview(imageview)
    }
    //按钮监听
    func buttonClick(btn:UIButton){
            print(btn.titleLabel?.text)
        }
原文地址:http://blog.csdn.net/tubiebutu/article/details/46383489