当执行触摸移动时，如何设置我的图像(点)与新图像(点)的固定距离相同？-(void)touchesMoved:(NSSet*)toucheswithEvent:(UIEvent*)event{UITouch*touch=[touchesanyObject];CGPointtouchLocation=[touchlocationInView:touch.view];UIImageView*imageView=[[UIImageViewalloc]initWithImage:[UIImageimageNamed:@"Crayon_Black.png"]];imageView.center=