设备旋转时的UIToolbar高度

Question

From the iOS Human Interface Guidelines, iOS UI Element Usage Guidelines

On iPhone, take into account the automatic change in toolbar height that occurs on device rotation . In particular, make sure your custom toolbar icons fit well in the thinner bar that appears in landscape orientation. Don't specify the height of a toolbar programmatically.

I can see the height changing from 44 points to 32 points in Mail , Twitter for iPhone and Dropbox for example, but when I add a toolbar (with Interface Builder) and have my UIViewController subclass to automatically rotate ( shouldAutorotateToInterfaceOrientation: returns YES), the toolbar does not automatically change its height on device rotation.

The UIToolbar Class Reference does not mention this automatic change of height, so am I supposed to change it programmatically even though the HIG says Don't specify the height of a toolbar programmatically ?

Answer 1

您是否检查了工具栏的自动调整大小属性？

Answer 2

As noted by yonel and George in the comments from 7KV7 answer, changing the autoresizing mask does not work as intended on iOS 5.

I found another solution by using the -[UIView sizeThatFits:] method. Here is how I did it:

- (void) layoutForInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
    // Adjust the toolbar height depending on the screen orientation
    CGSize toolbarSize = [self.toolbar sizeThatFits:self.view.bounds.size];
    self.toolbar.frame = (CGRect){CGPointMake(0.f, CGRectGetHeight(self.view.bounds) - toolbarSize.height), toolbarSize};
    self.webView.frame = (CGRect){CGPointZero, CGSizeMake(CGRectGetWidth(self.view.bounds), CGRectGetMinY(self.toolbar.frame))};
}

Then I call this layoutForInterfaceOrientation: method in my view controller viewWillAppear: and willAnimateRotationToInterfaceOrientation:duration: methods.

The height is nonetheless changed programmatically but at least the value is not hardcoded.

Answer 3

This behavior is a lot simpler to achieve with auto layout. I've only tested in iOS8 but the following code works for me with the desired animation on orientation change:

public override func viewWillLayoutSubviews() {
    super.viewWillLayoutSubviews()
    toolbar.invalidateIntrinsicContentSize()
}

Answer 4

If you use a ViewController inside a NavigationController, you can use the NavigationController's toolbar instead of creating your own, and let it handle the resizing. This is what the ViewController's toolbarItems property is for, actually.