To drag a view we can either use the touch methods of UIViewController or we can use UIPanGestureRecognizer. UIPanGestureRecognizer is much easier and simple to implement. This blog explains how to use it.

1. Add pan gesture to the view (or any control that is a subclass of UIView) that is to be dragged.

[panImageView addGestureRecognizer:[[UIPinchGestureRecognizer alloc]initWithTarget:self action:@selector(handlePinch:)]];

2. Handle pan

-(void)handlePan:(UIPanGestureRecognizer*)pan {
   CGPoint translation = [pan translationInView:self.view];
    panImageView.center = CGPointMake(panImageView.center.x + translation.x,
                                         panImageView.center.y + translation.y);
    [pan setTranslation:CGPointMake(0, 0) inView:self.view];
}

panImageView is the image view which we are going to drag.