Swift 3版本应该是:

let myButton:UIButton = {
    let myButton = UIButton() // If you want to set the type use like
                              // UIButton(type: .RoundedRect) or
                              // UIButton(type: .Custom)
    myButton.setTitle("Hai Touch Me", for: .normal)
    myButton.setTitleColor(UIColor.blue, for: .normal)
    myButton.frame = CGRect(x: 20, y: 20, width: 100, height: 40)

    myButton.addTarget(self, action: #selector(ViewController.pressedAction(_:)), for: .touchUpInside)
    self.view.addSubview(myButton)

    return myButton
}()

试试这个:

首先把它写在你的。h文件的viewcontroller

UIButton *btn;

现在把这个写在viewcontrollers viewDidLoad的。m文件中。

btn=[[UIButton alloc]initWithFrame:CGRectMake(50, 20, 30, 30)];
[btn setBackgroundColor:[UIColor orangeColor]];
[btn setTitle: @"My Button" forState:UIControlStateNormal];
[btn setTitleColor: [UIColor blueVolor] forState:UIControlStateNormal];
[btn.layer setBorderWidth:1.0f];
[btn.layer setBorderColor:[UIColor BlueVolor].CGColor];
//adding action programatically
[btn addTarget:self action:@selector(btnClicked:) forControlEvents:UIControlEventTouchUpInside];
[self.view addSubview:btn];

在视图控制器的。m文件中写入viewDidLoad方法的外部

- (IBAction)btnClicked:(id)sender
{
  //Write a code you want to execute on buttons click event
}

objective - c

UIButton *but= [UIButton buttonWithType:UIButtonTypeRoundedRect];
[but addTarget:self action:@selector(buttonClicked:) forControlEvents:UIControlEventTouchUpInside];
 [but setFrame:CGRectMake(52, 252, 215, 40)];
[but setTitle:@"Login" forState:UIControlStateNormal];
[but setExclusiveTouch:YES];

 // if you like to add backgroundImage else no need
   [but setbackgroundImage:[UIImage imageNamed:@"XXX.png"] forState:UIControlStateNormal];

[self.view addSubview:but];

-(void) buttonClicked:(UIButton*)sender
 {
NSLog(@"you clicked on button %@", sender.tag);
 }

斯威夫特

    let myButton = UIButton() // if you want to set the type use like UIButton(type: .RoundedRect) or UIButton(type: .Custom)
    myButton.setTitle("Hai Touch Me", forState: .Normal)
    myButton.setTitleColor(UIColor.blueColor(), forState: .Normal)
    myButton.frame = CGRectMake(15, 50, 300, 500)
    myButton.addTarget(self, action: "pressedAction:", forControlEvents: .TouchUpInside)

    self.view.addSubview( myButton)


func pressedAction(sender: UIButton!) {
   // do your stuff here 
  NSLog("you clicked on button %@", sender.tag)
}

Swift3及以上

  let myButton = UIButton() // if you want to set the type use like UIButton(type: .RoundedRect) or UIButton(type: .Custom)
    myButton.setTitle("Hi, Click me", for: .normal)
    myButton.setTitleColor(UIColor.blue, for: .normal)
    myButton.frame = CGRect(x: 15, y: 50, width: 300, height: 500)

    myButton.addTarget(self, action: #selector(pressedAction(_:)), for: .touchUpInside)
    self.view.addSubview( myButton)



func pressedAction(_ sender: UIButton) {
   // do your stuff here 
  print("you clicked on button \(sender.tag)")
}

迅捷用户界面

例如，你可以从SwiftUI开发者门户网站获得一步一步的实现

import SwiftUI

struct ContentView : View {
    var body: some View {
        VStack {

            Text("Target Color Black")
             Button(action: { 
                 /* handle button action here */ })
            {
         Text("your Button Name")
          .color(.white)
                        .padding(10)
                        .background(Color.blue)
                        .cornerRadius(5)
                        .shadow(radius: 5)
                        .clipShape(RoundedRectangle(cornerRadius: 5))
     }


        }
    }
}

#if DEBUG
struct ContentView_Previews : PreviewProvider {
    static var previews: some View {
        ContentView()
    }
}
#endif

UIButton *saveLibrary=[UIButton buttonWithType:UIButtonTypeCustom];

[saveLibrary setTitle:@"Library" forState:UIControlStateNormal];

[saveLibrary setBackgroundColor:[UIColor redColor]];

[saveLibrary addTarget:self 
action:@selector(saveOnGalleryButtonIsPressed) forControlEvents:UIControlEventTouchUpInside];

[saveLibrary setImage:[UIImage imageWithContentsOfFile:[[[NSBundle mainBundle] bundlePath] stringByAppendingString:@"/library225.png"]]forState:UIControlStateNormal];

saveLibrary.frame=CGRectMake(323, 15, 75, 75);  

[self.view addSubview:saveLibrary];

对于Swift 3(更短的代码)

let button = UIButton(type: UIButtonType.custom)
button.frame = CGRect(x: 0, y: 0, width: 200.0, height: 40.0)
button.addTarget(nil, action: #selector(tapButton(_:)), for: UIControlEvents.touchUpInside)
button.tintColor = UIColor.white
button.backgroundColor = UIColor.red
button.setBackgroundImage(UIImage(named: "ImageName"), for: UIControlState.normal)
button.setTitle("MyTitle", for: UIControlState.normal)
button.isEnabled = true

func tapButton(sender: UIButton) {

}

对于Swift 2.2(带有新的“selector”声明)。

let btn = UIButton(type: UIButtonType.System) as UIButton
btn.frame = CGRectMake(0, 0, 100, 20) // set any frame you want
btn.setTitle("MyAction", forState: UIControlState.Normal)
btn.addTarget(self, action: #selector(MyClass.myAction(_:)), forControlEvents: UIControlEvents.TouchUpInside)
self.view.addSubview(btn)


func myAction(sender:UIButton!){
  // Some action 
}