iphone - 'UIAttachmentBehavior' 没有可见的@interface 在 DynamicsCatalog.xcodeproj 中声明选择器 initWithItem

Question

我刚从 Apple 开发者门户网站下载 DynamicsCatalog.xcodeproj，但出现此错误:

“UIAttachmentBejavior”没有可见的@interface decleares 选择器 initwititem

在这一行:

UIAttachmentBehavior *attachmentBehavior = [[UIAttachmentBehavior alloc] initWithItem:self.square1 point:attachmentPoint attachedToAnchor:squareCenterPoint];

在 APLAttachmentsViewController.m 中

这是该行的上下文:

- (void)viewDidLoad
{
    [super viewDidLoad];

    UIDynamicAnimator* animator = [[UIDynamicAnimator alloc] initWithReferenceView:self.view];
    UICollisionBehavior* collisionBehavior = [[UICollisionBehavior alloc] initWithItems:@[self.square1]];

    CGPoint squareCenterPoint = CGPointMake(self.square1.center.x, self.square1.center.y - 100.0);
    CGPoint attachmentPoint = CGPointMake(-25.0, -25.0);
    /*
     By default, an attachment behavior uses the center of a view. By using a small offset, we get a more interesting effect which will cause the view to have rotation movement when dragging the attachment.
     */
    UIAttachmentBehavior *attachmentBehavior = [[UIAttachmentBehavior alloc] initWithItem:self.square1 point:attachmentPoint attachedToAnchor:squareCenterPoint];

    collisionBehavior.translatesReferenceBoundsIntoBoundary = YES;

    // Show visually the attachment points
    self.redSquare.center = attachmentBehavior.anchorPoint;
    self.blueSquare.center = CGPointMake(25.0, 25.0);

    [animator addBehavior:attachmentBehavior];
    self.animator = animator;

    self.attachmentBehavior = attachmentBehavior;
}

你们中有人知道为什么或如何修复此演示代码吗？

Answer 1

看看 class reference for UIAttachmentBehavior : initWithItem:point:attachedToAnchor: 没有声明，它似乎在某个时候被删除了。使用其他初始化程序之一:

– initWithItem:attachedToAnchor:
– initWithItem:attachedToItem:
– initWithItem:offsetFromCenter:attachedToAnchor:
– initWithItem:offsetFromCenter:attachedToItem:offsetFromCenter:

您正在使用的选择器实际上已重命名为 initWithItem:offsetFromCenter:attachedToAnchor: