面試的時(shí)候敦跌，有一次被問(wèn)到怎樣擴(kuò)大Button的點(diǎn)擊區(qū)域贴谎，當(dāng)時(shí)回答的不是讓面試官很滿(mǎn)意憋沿，現(xiàn)在來(lái)總結(jié)一下旺芽。
在網(wǎng)上看了很多的方法，最后看到一篇關(guān)于用Rutime機(jī)制來(lái)實(shí)現(xiàn)的方法辐啄，真的很好用 參考文章
話不多說(shuō)采章，上代碼
一、創(chuàng)建一個(gè)button的分類(lèi)
button.h文件
#import <UIKit/UIKit.h>
#import <objc/runtime.h>
@interface UIButton (ExpandTheClickArea)
- (void)setEnlargeEdge:(CGFloat) size;
- (void)setEnlargeEdgeWithTop:(CGFloat) top right:(CGFloat) right bottom:(CGFloat) bottom left:(CGFloat) left;
@end
button.m文件
#import "UIButton+ExpandTheClickArea.h"
@implementation UIButton (ExpandTheClickArea)
static char topNameKey;
static char rightNameKey;
static char bottomNameKey;
static char leftNameKey;
- (void)setEnlargeEdge:(CGFloat) size
{
objc_setAssociatedObject(self, &topNameKey, [NSNumber numberWithFloat:size], OBJC_ASSOCIATION_COPY_NONATOMIC);
objc_setAssociatedObject(self, &rightNameKey, [NSNumber numberWithFloat:size], OBJC_ASSOCIATION_COPY_NONATOMIC);
objc_setAssociatedObject(self, &bottomNameKey, [NSNumber numberWithFloat:size], OBJC_ASSOCIATION_COPY_NONATOMIC);
objc_setAssociatedObject(self, &leftNameKey, [NSNumber numberWithFloat:size], OBJC_ASSOCIATION_COPY_NONATOMIC);
}
- (void)setEnlargeEdgeWithTop:(CGFloat) top right:(CGFloat) right bottom:(CGFloat) bottom left:(CGFloat) left
{
objc_setAssociatedObject(self, &topNameKey, [NSNumber numberWithFloat:top], OBJC_ASSOCIATION_COPY_NONATOMIC);
objc_setAssociatedObject(self, &rightNameKey, [NSNumber numberWithFloat:right], OBJC_ASSOCIATION_COPY_NONATOMIC);
objc_setAssociatedObject(self, &bottomNameKey, [NSNumber numberWithFloat:bottom], OBJC_ASSOCIATION_COPY_NONATOMIC);
objc_setAssociatedObject(self, &leftNameKey, [NSNumber numberWithFloat:left], OBJC_ASSOCIATION_COPY_NONATOMIC);
}
- (CGRect)enlargedRect
{
NSNumber* topEdge = objc_getAssociatedObject(self, &topNameKey);
NSNumber* rightEdge = objc_getAssociatedObject(self, &rightNameKey);
NSNumber* bottomEdge = objc_getAssociatedObject(self, &bottomNameKey);
NSNumber* leftEdge = objc_getAssociatedObject(self, &leftNameKey);
if (topEdge && rightEdge && bottomEdge && leftEdge)
{
return CGRectMake(self.bounds.origin.x - leftEdge.floatValue,
self.bounds.origin.y - topEdge.floatValue,
self.bounds.size.width + leftEdge.floatValue + rightEdge.floatValue,
self.bounds.size.height + topEdge.floatValue + bottomEdge.floatValue);
}
else
{
return self.bounds;
}
}
- (UIView*)hitTest:(CGPoint) point withEvent:(UIEvent*) event
{
CGRect rect = [self enlargedRect];
if (CGRectEqualToRect(rect, self.bounds))
{
return [super hitTest:point withEvent:event];
}
return CGRectContainsPoint(rect, point) ? self : nil;
}
@end
實(shí)現(xiàn)
#import "ViewController.h"
#import "UIButton+ExpandTheClickArea.h"
@interface ViewController ()
@end
@implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
UIButton *btnCancel = [UIButton buttonWithType:UIButtonTypeCustom];
btnCancel.frame = CGRectMake(100, 100, 10, 10);
btnCancel.backgroundColor = [UIColor redColor];
//在此可以隨意設(shè)置button上下左右的點(diǎn)擊范圍
[btnCancel setEnlargeEdgeWithTop:10 right:10 bottom:10 left:0];
[btnCancel addTarget:self action:@selector(ExpandTheArea) forControlEvents:UIControlEventTouchUpInside];
[self.view addSubview:btnCancel];
}
-(void)ExpandTheArea{
NSLog(@"哈哈");
}
@end
二壶辜、什么是objc_setAssociatedObject
iOS objc_setAssociatedObject 關(guān)聯(lián)對(duì)象的學(xué)習(xí)
