设置只为View加一条边框，子视图大小超出父视图大小，边框在子视图下边显示

#import "ViewController.h"

@interface ViewController ()

@property (strong,nonatomic) UIView *Fview;

@property (strong,nonatomic) UIView *Zview;

@end

@implementation ViewController

- (void)viewDidLoad {

[super viewDidLoad];

// Do any additional setup after loading the view, typically from a nib.

_Fview = [[UIView alloc]initWithFrame:CGRectMake(120,200, 100, 100)];

_Fview.backgroundColor = [UIColor greenColor];

[self.view addSubview:_Fview];

CALayer *blayer = [[CALayer alloc]init];

blayer.frame =CGRectMake(0, 0, 100, 1);

blayer.backgroundColor = [UIColor blackColor].CGColor;

[_Fview.layer addSublayer:blayer];

_Zview = [[UIView alloc]initWithFrame:CGRectMake(20,-10, 100, 120)];

_Zview.backgroundColor = [UIColor redColor];

[_Fview addSubview:_Zview];

}

- (void)didReceiveMemoryWarning {

[super didReceiveMemoryWarning];

// Dispose of any resources that can be recreated.

}

@end