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
}()

在这里你可以动态创建一个UIButton:

//For button image
UIImage *closebtnimg = [UIImage imageNamed:@"close_btn.png"];
//Custom type button
btnclose = [[UIButton buttonWithType:UIButtonTypeCustom]retain];
//Set frame of button means position
btnclose.frame = CGRectMake(103, 257, 94, 32);
//Button with 0 border so it's shape like image shape
[btnclose.layer setBorderWidth:0];
//Set title of button
[btnclose setTitle:@"CLOSE" forState:UIControlStateNormal];
[btnclose addTarget:self action:@selector(methodname:) forControlEvents:UIControlEventTouchUpInside];
//Font size of title
btnclose.titleLabel.font = [UIFont boldSystemFontOfSize:14];
//Set image of button
[btnclose setBackgroundImage:closebtnimg forState:UIControlStateNormal];

要以编程方式在控制器视图中添加一个按钮，请使用以下命令:

-(void)viewDidLoad
{
   UIButton * btn = [UIButton buttonWithType:UIButtonTypeRoundedRect];
   btn.frame = CGRectMake(0, 0, 100, 50);
   [btn setTitle:@"Hello, world!" forState:UIControlStateNormal];
   [self.view addSubview:btn];
}

要加入其中三种，冲洗并重复。

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];

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 *)addButton:(NSString *)title :(CGRect)frame : (SEL)selector :(UIImage *)image :(int)tag{

UIButton *btn = [UIButton buttonWithType:UIButtonTypeCustom];
btn.frame = frame;
[btn addTarget:self action:selector forControlEvents:UIControlEventTouchUpInside];
[btn setTitle:title forState:UIControlStateNormal];
[btn setImage:image forState:UIControlStateNormal];
btn.backgroundColor = [UIColor clearColor];
btn.tag = tag;

return btn;

}

你可以把它添加到视图中:

[self.view addSubview:[self addButton:nil :self.view.frame :@selector(btnAction:) :[UIImage imageNamed:@"img.png"] :1]];