增大或缩小按钮的点击触发区域

当遇到增大或缩小按钮的点击触发区域，或者不规则形状按钮的事件触发

自定义按钮，重写- (BOOL)pointInside:(CGPoint)point withEvent:(UIEvent *)event的方法， 在pointInside方法里面设置触发的范围即可

//左右增加的区域
@property(nonatomic,assign) CGFloat leftRightLength;
//上下增加的区域
@property(nonatomic,assign) CGFloat topBottomLenght;

- (BOOL)pointInside:(CGPoint)point withEvent:(UIEvent *)event {
    
    CGRect originBounds = self.bounds;
    CGFloat newX = originBounds.origin.x - self.leftRightLength;
    CGFloat newY = originBounds.origin.y - self.topBottomLenght;
    CGFloat newW = originBounds.size.width + self.leftRightLength*2;
    CGFloat newH = originBounds.size.height + self.leftRightLength*2;
    CGRect currentBounds = CGRectMake(newX, newY, newW, newH);
    NSLog(@"currentBounds = %@",NSStringFromCGRect(currentBounds));
    NSLog(@"point = %@",NSStringFromCGPoint(point));
    return CGRectContainsPoint(currentBounds, point);
}

一个事件的传递， 首先会调用页面的- (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event方法， 在hitTest方法里面判断是否有子控件可以响应，如果没有就会通过- (BOOL)pointInside:(CGPoint)point withEvent:(UIEvent *)event判断自己能否响应

hitTest:withEvent:方法的伪代码

//返回最适合处理事件的视图，最好在父视图中指定子视图的响应
- (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event {
    if (!self.userInteractionEnabled || !self.hidden || self.alpha <= 0.01) {
        return nil;
    }
    
    if ([self pointInside:point withEvent:event]) {
        
        for (UIView *subView in [self.subviews reverseObjectEnumerator]) {
            CGPoint subPoint = [subView convertPoint:point fromView:self];
            
            UIView *bestView = [subView hitTest:subPoint withEvent:event];
            if (bestView) {
                return bestView;
            }
        }
        return self;
    }

    return nil;
}