'action:@selector(aMethod:)'这样写方法:

- (void)aMethod:(UIButton*)button
   {
         NSLog(@"Button  clicked.");
  }

这对我很管用。谢谢。KS。

UIButton *buttonName = [UIButton
buttonWithType:UIButtonTypeRoundedRect];
[buttonName addTarget:self 
    action:@selector(aMethod:)forControlEvents:UIControlEventTouchDown];
[buttonName setTitle:@"Show View" forState:UIControlStateNormal];
.frame = CGRectMake(80.0, 210.0, 160.0, 40.0); [view
addSubview:buttonName];

UIButton *custombutton = [UIButton buttonWithType:UIButtonTypeRoundedRect];
[custombutton addTarget:self
                 action:@selector(aMethod:)
       forControlEvents:UIControlEventTouchUpInside];
[custombutton setTitle:@"Click" forState:UIControlStateNormal];
custombutton.frame = CGRectMake(80.0, 110.0, 160.0, 40.0);
custombutton.titleLabel.textColor = [UIColor colorWithRed: 2.0f/255.0f green: 155.0f/255.0f blue: 213.0f/255.0f  alpha:1];
 [custombutton setImage:[UIImage imageNamed:@"hh.png"] forState:UIControlStateNormal];
 [view addSubview:custombutton];

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
}()

- (void)viewDidLoad {
    [super viewDidLoad];
    [self addMyButton];   // Call add button method on view load
}

- (void)addMyButton{    // Method for creating button, with background image and other properties

    UIButton *playButton = [[UIButton buttonWithType:UIButtonTypeRoundedRect] retain];
    playButton.frame = CGRectMake(110.0, 360.0, 100.0, 30.0);
    [playButton setTitle:@"Play" forState:UIControlStateNormal];
    playButton.backgroundColor = [UIColor clearColor];
    [playButton setTitleColor:[UIColor whiteColor] forState:UIControlStateNormal ];
    UIImage *buttonImageNormal = [UIImage imageNamed:@"blueButton.png"];
    UIImage *strechableButtonImageNormal = [buttonImageNormal stretchableImageWithLeftCapWidth:12 topCapHeight:0];
    [playButton setBackgroundImage:strechableButtonImageNormal forState:UIControlStateNormal];
    UIImage *buttonImagePressed = [UIImage imageNamed:@"whiteButton.png"];
    UIImage *strechableButtonImagePressed = [buttonImagePressed stretchableImageWithLeftCapWidth:12 topCapHeight:0];
    [playButton setBackgroundImage:strechableButtonImagePressed forState:UIControlStateHighlighted];
    [playButton addTarget:self action:@selector(playAction:) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:playButton];  
}

UIButton * tmpBtn = [UIButton buttonWithType:UIButtonTypeCustom];
[tmpBtn addTarget:self action:@selector(clearCart:) forControlEvents:UIControlEventTouchUpInside];
tmpBtn.tag = k;
tmpBtn.frame = CGRectMake(45, 0, 15, 15);
[tmpBtn setBackgroundImage:[UIImage imageNamed:@"CloseButton.png"] forState:UIControlStateNormal];
[self.view addSubview:tmpBtn];