自动调整UIImageView的大小以适合基础图像

Question

I have a custom view defined in xib file, which has an UIImageView in it.

The image is added programmatically. I don't lnow the exact image size at compile time.

Height of an imageView is constant by design, and width must be dynamic.

UIImageView should automatically resize to fit image after setting it, but it doesn't.

I've tried:

• Setting "Intristic size = Placeholder" in UI Designer.
• Setting different modes like "Aspect fit" or "Aspect fill"
• Setting constraints (see screenshot)
• Setting size in code (see code)
• Searching at Google and Stackoverflow and trying code examples

Nothing has helped to achieve desired result.

There's my code:

@implementation EVACustomNavBar

-(id)initWithCoder:(NSCoder *)aDecoder
{
    self = [super initWithCoder:aDecoder];
    if(self)
    {
        [[NSBundle mainBundle] loadNibNamed:@"EVACustomNavBar" owner:self options:nil];
        self.view.frame = CGRectMake(self.view.frame.origin.x, self.view.frame.origin.y, self.frame.size.width, self.frame.size.height);
        [self addSubview:self.view];
    }
    return self;
}

-(void)setLogo:(UIImage *)logo
{
    NSLog(NSStringFromCGRect(self.logoView.bounds));
    NSLog(NSStringFromCGSize(logo.size));
    self.logoView.backgroundColor = [UIColor blackColor];
    self.logoView.image = logo;
    CGRect ivFrame = self.logoView.bounds;
    CGFloat aspectRatio = logo.size.width / logo.size.height;
    ivFrame.size.width = ivFrame.size.height * aspectRatio;
    self.logoView.bounds = ivFrame;
    NSLog(NSStringFromCGRect(self.logoView.bounds));
}

@end

I tried calling setLogo at viewDidLoad and viewDidAppear in my ViewController file.

I tried both logoView.bounds and logoView.frame. Output is:

logoView.bounds before setting: {{0, 0}, {0, 44}}
logo size: {82, 71}
logoView.bounds after setting{{0, 0}, {50.816898, 44}}

However I see this:

So even setting frame of UIImageView doesn't help.

Answer 1

尝试在IB中创建宽度约束，而不是设置图像视图的边界或框架，而是将其附加到类中的IBOutlet并更新宽度约束。