iOS 图片 的 聊天气泡显示 Objective-C

- (void)viewDidLoad {
[super viewDidLoad];

UIImageView *ImageView01 = [[UIImageView alloc] init];
[ImageView01 setFrame:CGRectMake(90, 190, 120, 180)];
[ImageView01 setImage:[UIImage imageNamed:@"style.jpg"]];
[self.view addSubview:ImageView01];

UIImage *bubble = [UIImage imageNamed:@"icon_chat_right_bg"];
UIImageView *ImageView = [[UIImageView alloc] init];
[ImageView setFrame:ImageView01.frame];
[ImageView setImage:[bubble stretchableImageWithLeftCapWidth:15 topCapHeight:15]];

CALayer *layer              = ImageView.layer;
layer.frame                 = (CGRect){{0,0},ImageView.layer.frame.size};
ImageView01.layer.mask = layer;
[ImageView01 setNeedsDisplay];