UIPopoverController 的奇怪错误 [英] Strange Error With UIPopoverController

问题描述

我正在尝试使用 UIImagePickerController 从用户的 iPhone/iPad 上的照片中获取照片.这段代码适用于 iPhone，但是当我在 iPad 上运行它时，调试器给我消息由于未捕获的异常‘NSGenericException’而终止应用程序，原因:‘-[UIPopoverController dealloc]到达而弹出窗口仍然可见.".我对 Objective-C 很陌生，所以我不确定是什么原因造成的，我没有释放任何东西并且我打开了 ARC.这是我的代码:视图控制器.m

I'm trying to use UIImagePickerController to grab a photo from the users Photos on their iPhone / iPad. This code works just fine for iPhone, but when I run it on iPad, the debugger gives me the message "Terminating app due to uncaught exception 'NSGenericException', reason: '-[UIPopoverController dealloc] reached while popover is still visible.". I'm very new to Objective-C, so I'm unsure of whats causing this, I do not dealloc anything and I have ARC turned on. Here is my code: ViewController.m

#import "PhotoViewController.h"


@implementation PhotoViewController
@synthesize grabButton;
@synthesize image;
@synthesize imgPicker;

- (IBAction)grabImage {
    if ([[UIDevice currentDevice] userInterfaceIdiom] == UIUserInterfaceIdiomPad) {
        UIPopoverController *popover = [[UIPopoverController alloc] initWithContentViewController:imgPicker];
        [popover presentPopoverFromRect:self.image.bounds inView:self.image permittedArrowDirections:UIPopoverArrowDirectionAny animated:YES];

    } else {
        [self presentModalViewController:imgPicker animated:YES];
    }
}

- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingImage:(UIImage *)img editingInfo:(NSDictionary *)editInfo {
    image.image = img;
    [[picker parentViewController] dismissModalViewControllerAnimated:YES];
}

- (void)viewDidLoad
{
    self.imgPicker = [[UIImagePickerController alloc] init];
    self.imgPicker.allowsImageEditing = YES;
    self.imgPicker.delegate = self;
    self.imgPicker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
    [super viewDidLoad];
    // Do any additional setup after loading the view from its nib.

}

推荐答案

UIPopover 是一个丑陋的拼凑对象的野兽.它必须是一个强大的属性和一个 iVar，以确保不会过早地达到 Dealloc.将其添加到 .h 中，如下所示:

UIPopover is an ugly patchwork beast of an object. It must be a strong property and an iVar to ensure that Dealloc isn't reached prematurely. Add this in the .h Like so:

@interface MyClass: NSObject {
    UIPopover *_popover;
}
@property (nonatomic, strong) UIPopover * popover;

//.m 

@synthesize popover = _popover;

当您实例化弹出框时，将其分配给属性或实例:

When you instantiate the popover, assign it to either the property or the instance:

self.popover = [[UIPopoverController alloc] initWithContentViewController:imgPicker];

或

_popover = [[UIPopoverController alloc] initWithContentViewController:imgPicker];

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