@property (nonatomic) CGPoint beginPoint;@property (nonatomic) BOOL    dragEnable;

//自定义button对触摸事件进行响应
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{    //dragEnable = NO 则不响应动作    if (!_dragEnable) {        return;    }    UITouch *touch = [touches anyObject];        //获取button的当前位置    _beginPoint = [touch locationInView:self];}

//拖动自定义button时响应
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event{    if (!_dragEnable) {        return;    }    UITouch *touch = [touches anyObject];        //获取要移动到的目标位置    CGPoint nowPoint = [touch locationInView:self];    
    //确定目标位置与开始位置的偏移量    float offsetX = nowPoint.x - _beginPoint.x;    float offsetY = nowPoint.y - _beginPoint.x;        //按照button的center属性移动button    self.center = CGPointMake(self.center.x + offsetX, self.center.y + offsetY);}

#import "MVButton.h"

- (void)viewDidLoad{    [super viewDidLoad];        MVButton *mvButton = [[MVButton alloc] initWithFrame:CGRectMake(100, 100, 100, 100)];    mvButton.backgroundColor = [UIColor yellowColor];    mvButton.dragEnable = YES;        [self.view addSubview:mvButton];}