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 
}

-(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]];

UIButton *button=[UIButton buttonWithType:UIButtonTypeCustom];

[button setTitle:@"Click" forState:UIControlStateNormal];

[button setTitleColor:[UIColor blackColor]forState:UIControlStateNormal];

button.frame=CGRectMake(self.view.frame.origin.x+10,self.view.frame.size.height/2, self.view.frame.size.width-20, self.view.frame.size.height-500);

 button.titleLabel.font=[UIFont fontWithName:@"Helvetica" size:20];

[button addTarget:selfaction:@selector(aMethod)forControlEvents:UIControlEventTouchUpInside];

[button setBackgroundColor:[UIColor grayColor]];

[self.view addSubview:button];

-(void)addStuffToView
{
    UIButton *aButton = [[UIButton alloc] initWithFrame:CGRectMake(20, 20, 20, 20)]; //(x, y, width, height of button on screen
    [aButton setTitle:@"Button" forState:UIControlStateNormal];//puts the text on the button
    aButton.titleLabel.font = somefont;//sets the font if one is already stated
    aButton.titleLabel.font = [UIFont fontWithName:@"Arial-MT" size:12];//sets the font type and size
    [aButton addTarget:self action:@selector(back) forControlEvents:UIControlEventTouchUpInside];//see back method below
    [aButton setBackgroundImage:[UIImage imageNamed:@"someImage.png"] forState:UIControlStateNormal];//sets the image of the button
    [self.view addSubview:back];
}

-(void)back
{
    UIAlertView *alert = [[UIAlertView alloc]initWithTitle.....]
}

-(void)viewDidLoad
{
    [super viewDidLoad];
    [self addStuffToView];//adds all items built in this method to the view
}

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

- (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];  
}