UI给的图有时候小，或者需求是扩大button的点击区域，一般操作是改变button的size，还有就是不改变frame的情况下单独扩大button的点击区域。
第一种方法：继承UIButton，重写以下方法
-(BOOL)pointInside:(CGPoint)point withEvent:(UIEvent*)event
{
CGRect bounds = self.bounds;
//扩大原热区直径至26，可以暴露个接口，用来设置需要扩大的半径。
CGFloat widthDelta = MAX(26, 0);
CGFloat heightDelta = MAX(26, 0);
bounds = CGRectInset(bounds, -0.5 * widthDelta, -0.5 * heightDelta);
return CGRectContainsPoint(bounds, point);
}
第二种方法：重写以下方法
- (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event
{
CGRect rectBig = CGRectInset(self.bounds, -(27.0/2), -(27.0/2));
if (CGRectContainsPoint(rectBig, point)) {
return self;
}else{
return nil;
}
return self;
}
上面所做的变化点击区域还是矩形，如果需要将点击区域规定在圆形范围内，可以这样做：
-(UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event{
[super hitTest:point withEvent:event];
CGPoint center = CGPointMake(self.bounds.size.width/2, self.bounds.size.height/2);
//当然这个半径也可以扩大
CGFloat raidus = self.frame.size.height >= self.frame.size.width ?self.frame.size.width/2 :self.frame.size.width/2;
//传入中心点 实时点击点 与半径判断 点击点是否在半径区域内
BOOL pointInRound =[self touchPointInsideCircle:center radius:raidus targetPoint:point];
if (pointInRound) {
return self;
}else
{
return nil;
}
}
//用来判断 圆形点击区域
- (BOOL)touchPointInsideCircle:(CGPoint)center radius:(CGFloat)radius targetPoint:(CGPoint)point
{
CGFloat dist = sqrtf((point.x - center.x) * (point.x - center.x) +
(point.y - center.y) * (point.y - center.y));
return (dist <= radius);
}
