扩大视图点击区域

导语

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在工作中，经常创建一些视图(比如button)，这时button很小，点击时，总感到不精准，有时我们会在这个小button上放一个大一点的透明button。但是有没有好烦燥呀。

分类介入UIView+ExtendTouchRect

写这个分类，是受到一篇blog的启发。在这里感谢他的作者，作者名我忘记了。
分类写好后，一行代码解决问题

使用代码

self.button.touchExtendInset = UIEdgeInsetsMake(-10, -10, -10, -10)

实现代码如下

void Swizzle(Class c, SEL orig, SEL new) { Method origMethod = class_getInstanceMethod(c, orig); Method newMethod = class_getInstanceMethod(c, new); if (class_addMethod(c, orig, method_getImplementation(newMethod), method_getTypeEncoding(newMethod))){ class_replaceMethod(c, new, method_getImplementation(origMethod), method_getTypeEncoding(origMethod)); } else { method_exchangeImplementations(origMethod, newMethod); } }
@implementation UIView (ExtendTouchRect)
+ (void)load { Swizzle(self, @selector(pointInside:withEvent:), @selector(myPointInside:withEvent:)); }
- (BOOL)myPointInside:(CGPoint)point withEvent:(UIEvent *)event { if (UIEdgeInsetsEqualToEdgeInsets(self.touchExtendInset, UIEdgeInsetsZero) || self.hidden || ([self isKindOfClass:UIControl.class] && !((UIControl *)self).enabled)) { return [self myPointInside:point withEvent:event]; // original implementation } CGRect hitFrame = UIEdgeInsetsInsetRect(self.bounds, self.touchExtendInset); hitFrame.size.width = MAX(hitFrame.size.width, 0); // don't allow negative sizes hitFrame.size.height = MAX(hitFrame.size.height, 0); return CGRectContainsPoint(hitFrame, point); }
static char touchExtendInsetKey;
- (void)setTouchExtendInset:(UIEdgeInsets)touchExtendInset { objc_setAssociatedObject(self, &touchExtendInsetKey, [NSValue valueWithUIEdgeInsets:touchExtendInset], OBJC_ASSOCIATION_RETAIN); }
- (UIEdgeInsets)touchExtendInset { return [objc_getAssociatedObject(self, &touchExtendInsetKey) UIEdgeInsetsValue]; }
@end