-hitTest: 坐标点的转换

#import "ViewController.h"

@interface ViewController ()

@property (nonatomic, strong) UIView *brownView;
@property (nonatomic, strong) CALayer *blueLayer;

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    
    self.brownView = [[UIView alloc] init];
    self.brownView.frame = CGRectMake(100, 100, 250, 250);
    self.brownView.backgroundColor = [UIColor brownColor];
    [self.view addSubview:self.brownView];
    
    //create sublayer
    self.blueLayer = [CALayer layer];
    self.blueLayer.frame = CGRectMake(50.0f, 50.0f, 100.0f, 100.0f);
    self.blueLayer.backgroundColor = [UIColor blueColor].CGColor;
    //add it to our view
    [self.brownView.layer addSublayer:self.blueLayer];
}

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
    //get touch position relative to main view
    CGPoint point = [[touches anyObject] locationInView:self.view];
    //convert point to the brown layer's coordinates
    point = [self.brownView.layer convertPoint:point fromLayer:self.view.layer];
    //get layer using containsPoint:
    if ([self.brownView.layer containsPoint:point]) {
        //convert point to blueLayer’s coordinates
        point = [self.blueLayer convertPoint:point fromLayer:self.brownView.layer];
        if ([self.blueLayer containsPoint:point]) {
            [[[UIAlertView alloc] initWithTitle:@"Inside Blue Layer"
                                        message:nil
                                       delegate:nil
                              cancelButtonTitle:@"OK"
                              otherButtonTitles:nil] show];
        } else {
            [[[UIAlertView alloc] initWithTitle:@"Inside brownColor Layer"
                                        message:nil
                                       delegate:nil
                              cancelButtonTitle:@"OK"
                              otherButtonTitles:nil] show];
        }
    }
}

@end