ios - convertRect : toView: returns double size and twice the distance from the origin

我将 ImageView 传递给需要该 ImageView 大小的init方法。然后调用convertRect:toView:

- (id) initWithImageView:(UIImageView*) imageView {
    self = [super init];
    if (self) {
        CGRect imageViewFrame = [[imageView superview] convertRect: imageView.frame toView: self.view];
    }
}

被称为:

MyViewController *viewController = [[MyViewController alloc] initWithImageView:imageView];
viewController.delegate = self;
[self.tabBarController presentViewController:viewController animated:NO completion:nil];

然后是imageViewFrame

(origin = (x = 0, y = -120.22867049625003), size = (width = 750, height = 750))

imageView有一个框架

frame = (0 -60.1143; 375 375);

它的 super View 具有一个框架

frame = (0 0; 375 254.5);

为什么要按比例放大2倍？

在iPhone 6 plus(3x)模拟器上进行的进一步测试使imageViewFrame

(origin = (x = 0, y = -199.30952358000002), size = (width = 1242, height = 1242))

最初的测试是在iPhone 6模拟器(2x)上完成的。
为什么convertRect:toView:以像素而不是点工作？

最佳答案

在-initWithImageView:中，尚未生成self.view，您可以尝试暂存imageView，然后在-viewDidLoad中执行rect转换操作:

// If you don't user Interface Builder
- (void)loadView
{
   CGRect frame = <your_view_frame>;
   UIView * view = [[UIView alloc] initWithFrame:frame];
   self.view = view;
}

- (void)viewDidLoad
{
  [super viewDidLoad];

  CGRect imageViewFrame = [[imageView superview] convertRect:imageView.frame toView:self.view];
  ...
}

编辑

正如文档所说的-convertRect:toView:的view param:



如果您坚持使用-initWithImageView方法，请在-initWithImageView方法中声明一个自定义 View iVar，alloc＆init，然后在-loadView中，将iVar分配给self.view。当然，您过去在-initWithImageView中转换rect的方式应该是

CGRect frame = <your_view_frame>;
_iVarView = [[UIView alloc] initWithFrame:frame];
CGRect imageViewFrame = [[imageView superview] convertRect:imageView.frame
                                                    toView:_iVarView];

在-loadView中:

- (void)loadView
{
   self.view = _iVarView;
}

但是不建议这样做，我建议您以正确的 View 生命周期方法初始化UI。

关于ios - convertRect : toView: returns double size and twice the distance from the origin，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/29842391/