@interface NJViewController ()

@property (weak, nonatomic) IBOutlet UIView *customView;

@end

@implementation NJViewController

- (void)viewDidLoad

{

    [super viewDidLoad];

    UIPanGestureRecognizer  *pan = [[UIPanGestureRecognizer alloc] init];

    [self.customView addGestureRecognizer:pan];

    [pan addTarget:self action:@selector(panView:)];

}

- (void)panView:(UIPanGestureRecognizer *)pan

{

    // 返回的值是以手指按下的点为原点

    // 1 2 3 4 5

    CGPoint point = [pan translationInView:pan.view];

    NSLog(@"拖拽事件 %@", NSStringFromCGPoint(point));

    CGPoint temp = self.customView.center;

    temp.x += point.x;

    temp.y += point.y;

    self.customView.center = temp;

    // 理解不了就记住就OK

    [pan setTranslation:CGPointZero inView:pan.view];

}