objective-c - 显示弹出框时更改方向时应用程序崩溃。

Question

嗨朋友们，

单击工具栏按钮时，会出现我的弹出视图。当我将模拟器旋转到横向时，会显示以下错误消息：

Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[UIPopoverController presentPopoverFromRect:inView:permittedArrowDirections:animated:]: Popovers cannot be presented from a view which does not have a window.'

*** First throw call stack:
(0x1b69052 0x1868d0a 0x1b11a78 0x1b119e9 0x9ae72e 0x9affcb 0x9b26eb 0x281a39 0x1b34885 0x1b347a8 0x1c61aa 0x5490d8 0x54d499 0x54d584 0x11ede00 0x15ff4f0 0x1aa0833 0x1a9fdb4 0x1a9fccb 0x209a879 0x209a93e 0x51ca9b 0x29dd 0x2955)

处理我的按钮事件的代码是：

-(IBAction)name:(id)sender
{
    if ([_popover isPopoverVisible]) 
    {
        [_popover dismissPopoverAnimated:YES];
    }

    else {
        task * content = [[task  alloc] init];

        content.navigationItem.title =@"name"; 
        [content setDelegate:self];
        navController = [[UINavigationController alloc] initWithRootViewController: content]; 
        _popover = [[UIPopoverController alloc] 
                    initWithContentViewController:navController];
        _popover. popoverContentSize=CGSizeMake(350, 480);

        [_popover presentPopoverFromBarButtonItem:sender
                        permittedArrowDirections:UIPopoverArrowDirectionAny animated:YES];
    }

}

谢谢..

Answer 1

在这里，您需要添加代码以在更改方向时从视图中消除弹出框。

if ([_popover isPopoverVisible]) { [_popover dismissPopoverAnimated:YES]; }

因此，在更改方向时将代码放入方法 shouldAutorotateToInterfaceOrientation() 中，它将起作用。

- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation {

if ([_popover isPopoverVisible]) 
{
    [_popover dismissPopoverAnimated:YES];
}

return YES;

}

如果您还有其他问题，请随时提出。