Ios 如何通过PangestureRecognitor控制imageView的移动？

我想通过PangestureRecognitor这样移动imageView imageView可以缩放

如果imageView的位置为0,0，则它无法移动。 如果imageView的位置x超过60，则无法再移动。 如果imageView的位置y超过80，则不能再移动了。 当imageView的比例恢复为1.0时，其位置为0,0。 很难限制imageView的移动和位置。 我该怎么办

这是我的密码

img = [UIImage imageNamed:[NSString stringWithFormat:@"a.jpg"]];
imgView = [[UIImageView alloc]initWithImage:img];
imgView.frame = CGRectMake(0,0, self.view.frame.size.width, 448);
imgView.userInteractionEnabled = YES;
[self.view imgView];


- (void)panAction : (UIPanGestureRecognizer *)sender {

    CGPoint CGP = imgView.center;

    if(newScale != 1.0 && CGP.x-160 != 0 && CGP.y-224 != 50){

    CGPoint p = [sender translationInView:self.view];

    CGPoint movedPoint = CGPointMake(imgView.center.x + p.x, imgView.center.y + p.y);
    imgView.center = movedPoint;


    [sender setTranslation:CGPointZero inView:self.view];
    }
}


-(void)handlePinchGesture:(UIPinchGestureRecognizer *)gestureRecognizer {

    if([gestureRecognizer state] == UIGestureRecognizerStateBegan) {
        // Reset the last scale, necessary if there are multiple objects with different scales
        lastScale = [gestureRecognizer scale];
    }

    if ([gestureRecognizer state] == UIGestureRecognizerStateBegan ||
        [gestureRecognizer state] == UIGestureRecognizerStateChanged) {

        CGFloat currentScale = [[[gestureRecognizer view].layer valueForKeyPath:@"transform.scale"] floatValue];

        // Constants to adjust the max/min values of zoom
        const CGFloat kMaxScale = 2.0;
        const CGFloat kMinScale = 1.0;

        newScale = 1 -  (lastScale - [gestureRecognizer scale]);
        newScale = MIN(newScale, kMaxScale / currentScale);
        newScale = MAX(newScale, kMinScale / currentScale);
        CGAffineTransform transform = CGAffineTransformScale([[gestureRecognizer view] transform], newScale, newScale);
        [gestureRecognizer view].transform = transform;

        lastScale = [gestureRecognizer scale];  // Store the previous scale factor for the next pinch gesture call
    }


}

---

在平移手势动作中必须使用以下条件检查： 为您提供信息，在移动对象时，每次像素移动时都会定期调用此panAction方法

- (void)panAction : (UIPanGestureRecognizer *)sender {

if([(UIPanGestureRecognizer*)sender state] == UIGestureRecognizerStateBegan)
{
  //Do something whatever you need to be done while the pan gesture starts 
}
if ([(UIPanGestureRecognizer *)sender state] == UIGestureRecognizerStateChanged)
{
  //Do something whatever you need to be done while the imageView object is in the moving state  
}
if ([(UIPanGestureRecognizer *)sender state] == UIGestureRecognizerStateEnded){
 //Do something you need to do as you end the pan gesture.
}
}