UIImageView size suddenly change after set new image - ios

Question

I have a problem that I can't find the errors as titled. And I have searched so many times that similar or related questions, that can't solve.
I am building an App that can change the Image of A UIImageView with a button. everything is fine until I use another button to change the size of imageView (with UIView animateWithDuration + CGAffineTransformMakeRotation), then use that button for changing image.
strange output with no errors happen! the imageview size change back and the position move to other places.
Sorry about my poor english.
with graphics,
I have this view [no size changed view][1]
I use animateWithDuration + CGAffineTransformMakeRotation change the size & orientations, to make the view fullscreen like this [size changed view][2]
Then I change this image of this view by imageView.image = newImage(UIImage)
However, the view change to this [strange view][3] either the size or position are changed!
But, there's nothing if I change the image at Step 1 (no orientation & set frame)
Please help, I can't find the errors because there only one place that change the size&orientation of the view.
I wonder there is something UIImage would affect the UIImageView. But I can't find the answer.
(the photos are down below)
this is the code to rotate the image ivew
if there is already set image, after rotation, the image is also fine
But problem get after rotation, and then set the new image to the image view
-(void)transformToDirection:(NSInteger)dir
{
rotation = M_PI_2;
CGFloat screenW = [[UIScreen mainScreen] bounds].size.width;
CGFloat screenH = [[UIScreen mainScreen] bounds].size.height;
CGRect portraitFrame = _imageVIew.frame;
CGRect landscapeFrame = CGRectMake(0, 0, screenW, screenH);
switch (dir) {
case UIInterfaceOrientationPortrait:
{
[UIView animateWithDuration:1 delay:0 options:0 animations:^{
_imageVIew.transform = CGAffineTransformMakeRotation(3/4 * rotation);
[_imageVIew setFrame:portraitFrame];
}completion:^(BOOL finished){
isFullScreen = false;
}];
}
break;
case UIInterfaceOrientationLandscapeRight:
{
[UIView animateWithDuration:1 delay:0 options:0 animations:^{
_imageVIew.transform = CGAffineTransformMakeRotation(rotation);
[_imageVIew setFrame:landscapeFrame];
}completion:^(BOOL finished){
isFullScreen = true;
}];
}
break;
case UIInterfaceOrientationLandscapeLeft:
{
[UIView animateWithDuration:TIME_ANIMATE_FULLSCREEN delay:0 options:0 animations:^{
_imageVIew.transform = CGAffineTransformMakeRotation(-rotation);
[_imageVIew setFrame:landscapeFrame];
}completion:^(BOOL finished){
isFullScreen = true;
}];
}
break;
default:
break;
}
}
this is the image view set image (all new images are the same size), which is called by a button.
dispatch_async(dispatch_get_main_queue(), ^{
if (loadedimage) {
self.imageVIew.image = loadedimage;
} else {
self.PBMainImageVIew.image = nil;
dlog(#"request image failed");
}
});