@implementation ViewController

- (void)viewDidLoad {

    [super viewDidLoad];

    // Do any additional setup after loading the view.、

    UIButton *button1 =[UIButton buttonWithType:UIButtonTypeInfoDark];

    button1.frame = CGRectMake(175, 80, 40, 40);

    UIButton *button2=[UIButton buttonWithType:UIButtonTypeRoundedRect];

    button2.frame =CGRectMake(60, 180, 240, 44);

    button2.backgroundColor= [UIColor purpleColor];

    button2.tintColor = [UIColor yellowColor];

    [button2 setTitle:@"tap my" forState:UIControlStateNormal];

    [button2 addTarget:self action:@selector(buttonTap:) forControlEvents:UIControlEventTouchUpInside];

    UIButton *button3 =[UIButton buttonWithType:UIButtonTypeRoundedRect];

    button3.backgroundColor = [UIColor grayColor];

    button3.tintColor = [UIColor whiteColor];

    [button3 setTitle:@"tap me" forState:UIControlStateNormal];

    button3.frame = CGRectMake(60, 280, 260, 44);

    button3.layer.masksToBounds=YES;

    button3.layer.cornerRadius=10;

    button3.layer.borderWidth=4;

    button3.layer.borderColor = [UIColor lightGrayColor].CGColor;

    [self.view addSubview:button1];

    [self.view addSubview:button2];

    [self.view addSubview:button3];

}

-(void) buttonTap:(UIButton *)button

{

    UIAlertController *alert= [UIAlertController alertControllerWithTitle:@"Info" message:@"click" preferredStyle:UIAlertControllerStyleAlert ];

    UIAlertAction *okAction =[UIAlertAction actionWithTitle:@"ok" style:UIAlertActionStyleDefault handler:nil];

    [alert addAction:okAction];

    [self presentViewController:alert animated:YES completion: nil];

}