UIPickerView inside：[UIPickerView setFrame:]：固定的无效高度值

Question

我在UIPopoverController中使用UIPopoverController遇到了一个奇怪的问题。我编写此任务的代码如下：

    UIPickerView *select = [[UIPickerView alloc] initWithFrame:CGRectMake(0, 0, 320, 216)];
    select.delegate = self;
    select.dataSource = self;

    UIViewController *sortViewController = [[UIViewController alloc] init];
    sortViewController.view = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 320, 216)];

    sortViewController.view = select;
    sortViewController.preferredContentSize = CGSizeMake(320, 216);

    self.provincePickerPopover = [[UIPopoverController alloc] initWithContentViewController:sortViewController];
    self.provincePickerPopover.popoverContentSize = CGSizeMake(320, 216);
    self.provincePickerPopover.delegate = self;

    [self.provincePickerPopover presentPopoverFromRect:self.provinceField.frame inView:self.view permittedArrowDirections:UIPopoverArrowDirectionAny animated:YES];

问题是当弹出程序启动时，发生以下错误：

[UIPickerView setFrame:]: invalid height value 229.0 pinned to 216.0 

显然，在我的代码中，我从未使用229表示UIPickerView的高度。我怎么才能解决这个问题？

谢谢

Answer 1

添加选择器视图作为UIViewController视图的子视图。这样就可以消除错误了。所以，像这样：

 ...
 UIViewController *sortViewController = [[UIViewController alloc] init];
 sortViewController.view = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 320, 216)];

 [sortViewController.view addSubview:select]
 sortViewController.preferredContentSize = CGSizeMake(320, 216);
...