iOS hitTest withEvent

Question

我正在尝试使用UImageView withEvent获取对蒙面UIImageView下面的一个hitTest的引用。以下是我所拥有的不起作用的东西：

UIView A，包含3 UIImageViews作为子视图: panelOne、panelTwo和panelThree。panelThree占据了整个框架，但被蒙蔽成一个三角形，显示了面板一和二的部分。因此，我需要检测用户何时点击该矩形外部并将触摸发送到适当的UIImageView。

代码：(CollagePanel是UIImageView的子类)

-(void)triangleInASquare
{
    CGSize size = self.frame.size;
    CollagePanel *panelOne = [[CollagePanel alloc] initWithFrame:CGRectMake(0,0, size.width/2, size.height)];
    panelOne.panelScale = panelOne.frame.size.width/self.frame.size.width;
    panelOne.backgroundColor = [UIColor greenColor];

    CollagePanel *panelTwo = [[CollagePanel alloc] initWithFrame:CGRectMake(size.width/2,0, size.width/2, size.height)];
    panelTwo.panelScale = panelOne.frame.size.width/self.frame.size.width;
    panelTwo.backgroundColor = [UIColor purpleColor];

    CollagePanel *panelThree = [[CollagePanel alloc] initWithFrame:CGRectMake(0,0, size.width, size.height)];
    panelThree.backgroundColor = [UIColor orangeColor];

    UIBezierPath* trianglePath = [UIBezierPath bezierPath];
    [trianglePath moveToPoint:CGPointMake(0, panelThree.frame.size.height)];
    [trianglePath addLineToPoint:CGPointMake(panelThree.frame.size.width/2,0)];
    [trianglePath addLineToPoint:CGPointMake(panelThree.frame.size.width, panelTwo.frame.size.height)];
    [trianglePath closePath];

    // Mask the panels's layer to triangle.
    CAShapeLayer *triangleMaskLayer = [CAShapeLayer layer];
    [triangleMaskLayer setPath:trianglePath.CGPath];
    triangleMaskLayer.strokeColor = [[UIColor whiteColor] CGColor];
    panelThree.layer.mask = triangleMaskLayer;

    //Add border
    CAShapeLayer *borderLayer = [CAShapeLayer layer];
    borderLayer.strokeColor = [[UIColor whiteColor] CGColor];
    borderLayer.fillColor = [[UIColor clearColor] CGColor];
    borderLayer.lineWidth = 6;
    [borderLayer setPath:trianglePath.CGPath];

    [panelThree.layer addSublayer:borderLayer];

    NSMutableArray *tempArray = [[NSMutableArray alloc] init];
    [tempArray addObject:panelOne];
    [tempArray addObject:panelTwo];
    [tempArray addObject:panelThree];

    [self addGestureRecognizersToPanelsInArray:tempArray];
    [self addPanelsFromArray:tempArray];
    self.panelArray = tempArray;
}

-(void)handleTap: (UITapGestureRecognizer*) recognizer //coming from panel.imageView
{
    CGPoint tapPoint = [recognizer locationInView:self];
    NSLog(@"Location in self: %@", NSStringFromCGPoint(tapPoint));
    NSLog(@"self.subviews: %@", self.subviews);
    UIView *bottomView = [self hitTest:tapPoint withEvent:nil];
    NSLog(@"Bottom View: %@", bottomView);
}

NSLog of bottomView总是panelThree (最上面的面板)。据我所知，命中测试应该返回“最底层”的子视图。

Answer 1

你搞错了。它将返回一个视图，它会识别自己是被触摸的，并且离你的手指最近，离顶端更近。

如果视图在某一点上不承认自己是触摸，则需要覆盖。

- (BOOL)pointInside:(CGPoint)point withEvent:(UIEvent *)event

为了那景色。

我认为奥勒·贝格曼( Ole Begemann)型按钮是如何做到这一点的一个很好的例子。

在您的项目中，此方法可以确定路径中是否存在一个点：CGPathContainsPoint。

您的pointInside:withEvent:可能如下所示：

#import "CollagePanel.h"
#import <QuartzCore/QuartzCore.h>

@implementation CollagePanel
//
// ...
//
- (BOOL)pointInside:(CGPoint)point withEvent:(UIEvent *)event
{
    CGPoint p = [self convertPoint:point toView:[self superview]];
    if(self.layer.mask){
        if (CGPathContainsPoint([(CAShapeLayer *)self.layer.mask path], NULL, p, YES) )
            return YES;
    }else {
        if(CGRectContainsPoint(self.layer.frame, p))
            return YES;
    }
    return NO;
}

@end