mr.lefthand mr.lefthand - 1 year ago 347
Objective-C Question

Can't set titleView in the center of navigation bar because back button

I'm using an image view to display an image in my nav bar. The problem is that I can't set it to the center correctly because of the back button. I checked the related questions and had almost the same problem earlier that I solved, but this time I have no idea.

Earlier I solved this problem with fake bar buttons, so I tried to add a fake bar button to the right (and left) side, but it doesn't helped.

- (void) searchButtonNavBar {

CGRect imageSizeDummy = CGRectMake(0, 0, 25,25);

UIButton *dummy = [[UIButton alloc] initWithFrame:imageSizeDummy];

*searchBarButtonDummy =[[UIBarButtonItem alloc] initWithCustomView:dummy];
self.navigationItem.rightBarButtonItem = searchBarButtonDummy;


- (void)setNavBarLogo {

[self setNeedsStatusBarAppearanceUpdate];
CGRect myImageS = CGRectMake(0, 0, 44, 44);
UIImageView *logo = [[UIImageView alloc] initWithFrame:myImageS];
[logo setImage:[UIImage imageNamed:@"color.png"]];
logo.contentMode = UIViewContentModeScaleAspectFit;
self.navigationItem.titleView = logo;
[[UIBarButtonItem appearance] setTitlePositionAdjustment:UIOffsetMake(0.0f, 0.0f) forBarMetrics:UIBarMetricsDefault];


I think it should be workin fine because in this case the
has bar buttons on the same side. Is there any explanation why it worked with bar buttons that was created programmatically but doesn't works with the common back button?

Answer Source

UINavigationBar automatically centers its titleView as long as there is enough room. If the title isn't centered that means that the title view is too wide to be centered, and if you set the backgroundColor if your UIImageView you'll see that's exactly what is happening.

The title view is too wide because that navigation bar will automatically resize the title to hold its content, using -sizeThatFits:. This means that your title view will always be resized to the size of your image.

Two possible fixes:

  1. The image you're using is way too big. Use a properly sized 44x44 pt image with 2x and 3x versions.

  2. Wrap UIImageView inside of a regular UIView to avoid resizing.


UIImageView* imageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"test.jpeg"]];
imageView.contentMode = UIViewContentModeScaleAspectFit;

UIView* titleView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 44, 44)];
imageView.frame = titleView.bounds;
[titleView addSubview:imageView];

self.navigationItem.titleView = titleView;
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