为什么-frameForAlignmentRect:和-alignmentRectForFrame:不调用IOS

Question

我想在我的iOS应用程序中使用-frameForAlignmentRect:和-alignmentRectForFrame:指定对齐方式.但这种方法没有调用.

我有几乎相同的iOS和Mac代码.它在OS X上完美运行,但在iOS上运行不正常.

Mac版

@implementation CustomView

#define SHADOW_SIZE 10

- (void)drawRect:(NSRect)dirtyRect {
    NSBezierPath *path;

    [[NSColor redColor] set];
    path = [NSBezierPath bezierPathWithRect:dirtyRect];
    [path fill];

    // Draw a shadow
    NSRect rect = NSMakeRect(SHADOW_SIZE, 0, dirtyRect.size.width - SHADOW_SIZE, dirtyRect.size.height - SHADOW_SIZE);
    path = [NSBezierPath bezierPathWithRoundedRect:rect xRadius:32 yRadius:32];
    [[[NSColor blackColor] colorWithAlphaComponent:0.3f] set];
    [path fill];

    // Draw shape
    rect.origin = CGPointMake(0, SHADOW_SIZE);
    path = [NSBezierPath bezierPathWithRoundedRect:rect xRadius:32 yRadius:32];

    [[NSColor orangeColor] set];
    [path fill];
}

#define USE_ALIGNMENT_RECTS 1

#if USE_ALIGNMENT_RECTS
- (NSRect)frameForAlignmentRect:(NSRect)alignmentRect {
    NSRect rect = alignmentRect;
    rect.origin.y -= SHADOW_SIZE;
    rect.size.width += SHADOW_SIZE;
    rect.size.height += SHADOW_SIZE;
    return rect;
}

- (NSRect)alignmentRectForFrame:(NSRect)frame {
   NSRect rect;
    rect.origin = CGPointMake(frame.origin.x, frame.origin.y + SHADOW_SIZE);
    rect.size.width = frame.size.width - SHADOW_SIZE;
    rect.size.height = frame.size.height - SHADOW_SIZE;
    return rect;
}
#endif
@end

@implementation AppDelegate

- (void)awakeFromNib {

    _view = _window.contentView;

    CustomView *view = [[CustomView alloc] init];
    [self.view addSubview:view];

    view.translatesAutoresizingMaskIntoConstraints = NO;


    // Set vertical and horizontal alignments and view size
    // A little trick from here https://github.com/evgenyneu/center-vfl

    NSDictionary *views = NSDictionaryOfVariableBindings(_view, view);
    [self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"H:[_view]-(<=1)-[view(200)]"
                                                               options:NSLayoutFormatAlignAllCenterY
                                                               metrics:nil
                                                                 views:views]];

    [self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"V:[_view]-(<=1)-[view(200)]"
                                                                  options:NSLayoutFormatAlignAllCenterX
                                                                  metrics:nil
                                                                    views:views]];
}

@end

iOS版

@implementation MyView

#define SHADOW_SIZE 10

- (void)drawRect:(CGRect)dirtyRect {
    UIBezierPath *path;

    [[UIColor redColor] set];
    path = [UIBezierPath bezierPathWithRect:dirtyRect];
    [path fill];

    // Draw a shadow
    CGRect rect = CGRectMake(SHADOW_SIZE, SHADOW_SIZE, dirtyRect.size.width - SHADOW_SIZE, dirtyRect.size.height - SHADOW_SIZE);
    path = [UIBezierPath bezierPathWithRoundedRect:rect cornerRadius:32];
    [[[UIColor blackColor] colorWithAlphaComponent:0.3f] set];
    [path fill];

    // Draw shape
    rect.origin = CGPointMake(0, 0);
    path = [UIBezierPath bezierPathWithRoundedRect:rect cornerRadius:32];
    [[UIColor orangeColor] set];
    [path fill];
}

#define USE_ALIGNMENT_RECTS 1
#define USE_ALIGNMENT_INSETS 1

#if USE_ALIGNMENT_RECTS
- (CGRect)frameForAlignmentRect:(CGRect)alignmentRect {
    CGRect rect = alignmentRect;
    rect.size.width += SHADOW_SIZE;
    rect.size.height += SHADOW_SIZE;
    return rect;
}

- (CGRect)alignmentRectForFrame:(CGRect)frame {
    CGRect rect = frame;
    rect.size.width = frame.size.width - SHADOW_SIZE;
    rect.size.height = frame.size.height - SHADOW_SIZE;
    return rect;
}
#endif

#if USE_ALIGNMENT_INSETS
- (UIEdgeInsets)alignmentRectInsets {
    return UIEdgeInsetsMake(0, 0, SHADOW_SIZE, SHADOW_SIZE);
}
#endif

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];

    MyView *view = [[MyView alloc] init];
    [self.view addSubview:view];

    view.translatesAutoresizingMaskIntoConstraints = NO;

    UIView *superview = self.view;
    NSDictionary *views = NSDictionaryOfVariableBindings(superview, view);
    [self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"H:[superview]-(<=1)-[view(200)]"
                                                                  options:NSLayoutFormatAlignAllCenterY
                                                                  metrics:nil
                                                                    views:views]];

    [self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"V:[superview]-(<=1)-[view(200)]"
                                                                  options:NSLayoutFormatAlignAllCenterX
                                                                  metrics:nil
                                                                    views:views]];
}

@end

你可以看到iOS版本也-alignmentRectInsets:运行良好,但我想弄清楚什么是错误的-frameForAlignmentRect:和-alignmentRectForFrame:方法.