我有一个实现了touches began方法的UIControl：
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
[super touchesBegan:touches withEvent:event];
//More code goes here
这个UIControl的子类被实例化于一个视图控制器中，然后作为该视图控制器的子视图添加进去。我在UIControl的touches began方法下打了一个断点，但是这个方法从未被调用过。我阅读了一些资料，发现视图控制器有一些逻辑来决定是否将触摸事件传递给它的子视图。奇怪的是，在同一个视图控制器中，我有另一个UIControl的子类，当用户触碰它时，触摸事件会被传递给它！以下是完整的代码：
.h
#import <UIKit/UIKit.h>
@interface CustomSegment : UIView
@property (nonatomic, strong) UIImageView *bgImageView;
@property (nonatomic, assign) NSInteger segments;
@property (nonatomic, strong) NSArray *touchDownImages;
@property (nonatomic, readonly, assign) NSInteger selectedIndex;
@property (nonatomic, weak) id delegate;
- (id)initWithPoint:(CGPoint)point numberOfSegments:(NSInteger)_segments andTouchDownImages:(NSArray *)_touchDownImages;
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event;
@end
.m
#import "CustomSegment.h"
@implementation CustomSegment
@synthesize bgImageView, segments, touchDownImages, selectedIndex, delegate;
- (id)initWithPoint:(CGPoint)point
numberOfSegments:(NSInteger)_segments
andTouchDownImages:(NSArray *)_touchDownImages
{
self = [super initWithFrame:CGRectMake(point.x, point.y, [[_touchDownImages objectAtIndex:0] size].width, [[touchDownImages objectAtIndex:0] size].height)];
if (self)
{
touchDownImages = _touchDownImages;
segments = _segments;
bgImageView = [[UIImageView alloc] initWithImage:[touchDownImages objectAtIndex:0]];
[self addSubview:bgImageView];
}
return self;
}
- (BOOL)beginTrackingWithTouch:(UITouch *)touch withEvent:(UIEvent *)event
{
return YES;
}
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
//[super touchesBegan:touches withEvent:event];
UITouch *touch = [touches anyObject];
float widthOfSegment = [self frame].size.width / segments;
float bottomPoint = 0;
float topPoint = widthOfSegment;
for (int i = 0; i < segments; i++)
{
if ([touch locationInView:self].x > bottomPoint && [touch locationInView:self].x < topPoint)
{
[bgImageView setImage:[touchDownImages objectAtIndex:i]];
selectedIndex = i;
return;
}
else
{
bottomPoint = topPoint;
topPoint += topPoint;
}
}
}
@end