我想使用-frameForAlignmentRect:和-alignmentRectForFrame:在我的ios应用程序中指定对齐矩形。但是这个方法没有调用。
我有几乎相同的iOS和Mac代码。它在OS X上运行得很好，但在iOS上却不行。
Mac版本

@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

@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

最佳答案

您需要从以下位置更改代码：

view.translatesAutoresizingMaskIntoConstraints = NO;

self.view.translatesAutoresizingMaskIntoConstraints = NO;

- (UIEdgeInsets)alignmentRectInsets

- (CGRect)alignmentRectForFrame:(CGRect)frame

view.frame = CGRectMake(50,50,200,200);

- (void)addConstraints:(NSArray *)constraints

NSArray *horizontalConstraints = [NSLayoutConstraint constraintsWithVisualFormat:@"H:[superview]-(<=1)-[view(200)]" options:NSLayoutFormatAlignAllCenterY metrics:nil views:views];

NSArray *verticalConstraints = [NSLayoutConstraint constraintsWithVisualFormat:@"V:[superview]-(<=1)-[view(200)]" options:NSLayoutFormatAlignAllCenterX metrics:nil views:views];

NSArray *constraints = [[NSArray arrayWithArray:horizontalConstraints] arrayByAddingObjectsFromArray:verticalConstraints];

[NSLayoutConstraint activateConstraints:constraints];

关于ios - 为什么-frameForAlignmentRect:和-alignmentRectForFrame:不调用IOS，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/27061654/