SWIFT Button的基本用法

import UIKit

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {

    var window: UIWindow?

    func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
        self.window = UIWindow(frame: UIScreen.mainScreen().bounds)
        // Override point for customization after application launch.
        self.window!.backgroundColor = UIColor.whiteColor()
        self.window!.rootViewController = RootViewController()
        self.window!.makeKeyAndVisible()
        return true
    }

}

import UIKit

class RootViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
        //初始化button
        let btn = UIButton(type: UIButtonType.Custom)
        //尺寸
        btn.frame = CGRect(x: , y: , width: , height: )
        //背景颜色
        btn.backgroundColor = UIColor.redColor()
        //设置标题
        btn.setTitle("按钮", forState: UIControlState.Normal)
        //设置标题的颜色
        btn.setTitleColor(UIColor.greenColor(), forState: UIControlState.Normal)
        //添加点击事件
        btn.addTarget(self, action: "printSomeThing:", forControlEvents: UIControlEvents.TouchUpInside)
        //self.view加载子视图btn
        self.view.addSubview(btn)
    }
    //点击按钮执行的方法
    func printSomeThing(button:UIButton){
        print(button)
    }

}