Position of UIActivityViewController changed on changing orientation of device? - ios

Question

I’m building an article reading app.I implemented UIActivityViewController in UITableViewController programmatically.I am facing
an issue when i change the orientation of device the position of UIActivityViewController changed.
This my code:
indicator = [[UIActivityIndicatorView alloc]initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleGray];
if (UIDeviceOrientationIsLandscape([UIDevice currentDevice].orientation))
{
indicator.center = CGPointMake(350, 300);
[self.tableView addSubview:indicator];
[UIApplication sharedApplication].networkActivityIndicatorVisible = TRUE;
[indicator layoutIfNeeded];
}
else{
indicator.center = CGPointMake(200, 400);
[self.tableView addSubview:indicator];
[UIApplication sharedApplication].networkActivityIndicatorVisible = TRUE;
}
If it is possible by applying constraints programmatically,how i can do this.
Help is appreciated!

Answer 1

You could have indicator.center = self.tableview.center and call [self.view layoutIfNeeded] upon orientation.
Anyway I've just noticed something that looks odd. You do [self.view addSubview:indicator] but then you do [indicator bringSubviewToFront:self.view], I don't actually recall what the behaviour of this could be (probably nothing) but should be the other way round because indicator is subview of your self.view.
Furthermore, why do you add indicator twice (once for tableView and once for view) in the body of the else statement?
EDIT:
Or you could use Autolayout and forget about frames. Something like this:
NSLayoutConstraint *centerX = [NSLayoutConstraint constraintWithItem:indicator
attribute:NSLayoutAttributeCenterX
relatedBy:NSLayoutRelationEqual
toItem:self.tableView
attribute:NSLayoutAttributeCenterX
multiplier:1
constant:0];
[self.view addConstraint:centerX];
And do the same for centerY.

Answer 2

It looks like you're setting the position of the activityIndicator when it's first created and added to the view hierarchy. But you're not updating that position upon rotation.
You could achieve this update by either using constraints (a centerX and centerY constraint) as noted here by another responder, or overriding layoutSubviews and setting the center point of the activityIndicator to the center of the tableView.
Something like:
- (void)layoutSubviews
{
[super layoutSubviews];
self.activityIndicatorView.center = self.tableView.center;
}