iphone - UIView 忽略方向或粘到底部的容器

Question

我想以纵向模式在屏幕底部显示 UIView，因此当手机旋转并且水平方向将重新定位/调整所有子视图的大小时，一个 UIView 将保持原样，具有相同的大小和原始位置（即如果它在纵向模式的底部，则为水平方向的右端）。

有什么好的方法吗？

Answer 1

您可以像这样设置自动调整大小的掩码：

myView.autorezisingmask = UIViewAutorezingMaskFlexibleTopMargin;

这将使视图保持在底部。

Answer 2

我可以想到几种方法来做到这一点。我在下面展示的一种方式完全依赖于使用约束。为此，这 3 个按钮不应该在它们自己的透明视图中，而只是要旋转的视图的子视图（在我的示例中是 self.view）。我不认为这 3 个按钮的原始约束很重要，因为我在旋转时将它们删除，但我开始使用的约束具有 centerX 约束的中心按钮，到底部的固定距离，到左侧的标准水平距离和右键，所有三个按钮的基线对齐。在 viewDidLoad 中，我循环遍历 self.view 的所有约束并确定与这些按钮有关的所有内容，并将它们放入一个数组中，以便我可以删除它们并稍后将它们添加回来。

@interface ViewController ()
@property (strong,nonatomic) NSMutableArray *portraitConstraints;
@property (strong,nonatomic) NSMutableArray *landscapeConstraints;
@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    self.portraitConstraints = [NSMutableArray array];
    self.landscapeConstraints = [NSMutableArray array];
    for (NSLayoutConstraint *con in self.view.constraints) {
        if (con.firstItem == self.leftButton || con.secondItem == self.leftButton || con.firstItem == self.centerButton || con.secondItem == self.centerButton || con.firstItem == self.rightButton || con.secondItem == self.rightButton) {
            [self.portraitConstraints addObject:con];
        }
    }
}

- (void)willAnimateRotationToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation duration:(NSTimeInterval)duration {

    switch (interfaceOrientation) {
        case UIInterfaceOrientationLandscapeRight:{
            [self.view removeConstraints:self.portraitConstraints];
            [self.view removeConstraints:self.landscapeConstraints];
            [self.landscapeConstraints removeAllObjects];
            NSLayoutConstraint *centerYCon = [NSLayoutConstraint constraintWithItem:self.centerButton attribute:NSLayoutAttributeCenterY relatedBy:0 toItem:self.view attribute:NSLayoutAttributeCenterY multiplier:1 constant:0];
            NSLayoutConstraint *rightCon = [NSLayoutConstraint constraintWithItem:self.centerButton attribute:NSLayoutAttributeRight relatedBy:0 toItem:self.view attribute:NSLayoutAttributeRight multiplier:1 constant:-8];
            NSArray *stackCons= [NSLayoutConstraint constraintsWithVisualFormat:@"V:[left]-[center]-[right]" options:NSLayoutFormatAlignAllLeading metrics:nil views:@{@"left":self.leftButton, @"center":self.centerButton, @"right":self.rightButton}];
            [self.landscapeConstraints addObject:centerYCon];
            [self.landscapeConstraints addObject:rightCon];
            [self.landscapeConstraints addObjectsFromArray:stackCons];
            [self.view addConstraints:self.landscapeConstraints];
            break;
        }
        case UIInterfaceOrientationLandscapeLeft:{
            [self.view removeConstraints:self.portraitConstraints];
            [self.view removeConstraints:self.landscapeConstraints];
            [self.landscapeConstraints removeAllObjects];
            NSLayoutConstraint *centerYCon2 = [NSLayoutConstraint constraintWithItem:self.centerButton attribute:NSLayoutAttributeCenterY relatedBy:0 toItem:self.view attribute:NSLayoutAttributeCenterY multiplier:1 constant:0];
            NSLayoutConstraint *leftCon = [NSLayoutConstraint constraintWithItem:self.centerButton attribute:NSLayoutAttributeLeft relatedBy:0 toItem:self.view attribute:NSLayoutAttributeLeft multiplier:1 constant:8];
            NSArray *stackCons2= [NSLayoutConstraint constraintsWithVisualFormat:@"V:[left]-[center]-[right]" options:NSLayoutFormatAlignAllLeading metrics:nil views:@{@"left":self.leftButton, @"center":self.centerButton, @"right":self.rightButton}];
            [self.landscapeConstraints addObject:centerYCon2];
            [self.landscapeConstraints addObject:leftCon];
            [self.landscapeConstraints addObjectsFromArray:stackCons2];
            [self.view addConstraints:self.landscapeConstraints];
            break;
        }
        case UIInterfaceOrientationPortrait:{
            [self.view removeConstraints:self.landscapeConstraints];
            [self.view addConstraints:self.portraitConstraints];
            break;
        }
        default:
            break;
    }
}