如何使用Swift 3.0来做到这一点。

func createButton() {
    let button = UIButton(type: .system)
    button.frame = CGRect(x: 100.0, y: 100.0, width: 100.0, height: 100.0)
    button.setTitle(NSLocalizedString("Button", comment: "Button"), for: .normal)
    button.backgroundColor = .green
    button.addTarget(self, action: #selector(buttonAction(sender:)), for: .touchUpInside)
    view.addSubview(button)
}

@objc func buttonAction(sender: UIButton) {
    print("Button pushed")
}

从storyboard创建UIButton: 1 -将UIButton对象从对象库拖到storyboard文件中的ViewController 2 -节目助理编辑 3 -从上面创建的UIButton中右键拖动到你的类中。结果如下:

@IBAction func buttonActionFromStoryboard(sender: UIButton)
{
    println("Button Action From Storyboard")
}

为创建UIButton编程: 1-写入“override func viewDidLoad()”：

        let uiButton    = UIButton.buttonWithType(UIButtonType.System) as UIButton
        uiButton.frame  = CGRectMake(16, 116, 288, 30)
        uiButton.setTitle("Second", forState: UIControlState.Normal);
        uiButton.addTarget(self, action: "buttonActionFromCode:", forControlEvents: UIControlEvents.TouchUpInside)
        self.view.addSubview(uiButton)

2-添加IBAction功能:

@IBAction func buttonActionFromCode(sender:UIButton)
{
    println("Button Action From Code")
}

API没有改变——只有语法改变了。你可以创建一个UIButton并像这样添加它:

var button = UIButton(frame: CGRectMake(0, 0, 50, 50))
self.view.addSubview(button) // assuming you're in a view controller

这是可能的。除了使用swift语法之外，您几乎可以以相同的方式完成所有操作。例如，你可以用这样的代码创建一个UIButton:

 var button: UIButton = UIButton(frame: CGRectMake(0, 0, 100, 100))

是的，在模拟器里。有时它不会识别选择器，这似乎是一个错误。即使我面对的不是你的代码，然后我只是改变了动作名称(选择器)。它的工作原理

let buttonPuzzle:UIButton = UIButton(frame: CGRectMake(100, 400, 100, 50))
buttonPuzzle.backgroundColor = UIColor.greenColor()
buttonPuzzle.setTitle("Puzzle", forState: UIControlState.Normal)
buttonPuzzle.addTarget(self, action: "buttonAction:", forControlEvents: UIControlEvents.TouchUpInside)
buttonPuzzle.tag = 22;
self.view.addSubview(buttonPuzzle)

选择器函数在这里:

func buttonAction(sender:UIButton!)
{

    var btnsendtag:UIButton = sender
    if btnsendtag.tag == 22 {            
        //println("Button tapped tag 22")
    }
}

Uilabel code 

var label: UILabel = UILabel()
label.frame = CGRectMake(50, 50, 200, 21)
label.backgroundColor = UIColor.blackColor()
label.textColor = UIColor.whiteColor()
label.textAlignment = NSTextAlignment.Center
label.text = "test label"
self.view.addSubview(label)