在iOS 8中,我有从相机捕捉图像的问题,直到现在我正在使用这段代码

UIImagePickerController *controller=[[UIImagePickerController alloc] init];
controller.videoQuality=UIImagePickerControllerQualityTypeMedium;
controller.delegate=(id)self;
controller.sourceType=UIImagePickerControllerSourceTypeCamera;
[self presentViewController:controller animated:YES completion:nil];

但在iOS 8中,我得到了这个:

Snapshotting a view that has not been rendered results in an empty snapshot. Ensure your view has been rendered at least once before snapshotting or snapshot after screen updates.

我已经尝试了本文提供的解决方案

@property (strong,nonatomic)UIImagePickerController *controller;

_controller=[[UIImagePickerController alloc] init];
_controller.videoQuality=UIImagePickerControllerQualityTypeMedium;
_controller.delegate=(id)self;
_controller.sourceType=UIImagePickerControllerSourceTypeCamera;
_[self presentViewController:controller animated:YES completion:nil];

...
controller.modalPresentationStyle=UIModalPresentationFullScreen;
or
controller.modalPresentationStyle=UIModalPresentationCurrentContext;
...

double delayInSeconds = 0.1;
dispatch_time_t popTime = dispatch_time(DISPATCH_TIME_NOW, delayInSeconds * NSEC_PER_SEC);
dispatch_after(popTime, dispatch_get_main_queue(), ^(void){
    [self presentViewController:controller animated:YES completion:nil];
});

[self presentViewController:controller animated:YES completion:NULL];

[self presentViewController:controller animated:YES completion:^{

}];

任何想法?


当前回答

I don't have enough reputation points to comment on @greg's answer above, so will add my observations here. I have a Swift project for both iPad and iPhone. I have a method inside my main view controller (relevant bit below). When I test this on a phone, everything works properly and no warnings are generated. When I run it on an iPad, everything works properly but I see the warning about snapshotting the view. The interesting bit, however, is that when I run on an iPad without using the popover controller, everything works properly with no warning. Unfortunately, Apple mandates that the image picker must be used within a popover on iPad, if the camera is not being used.

    dispatch_async(dispatch_get_main_queue(), {
        let imagePicker: UIImagePickerController = UIImagePickerController();
        imagePicker.sourceType = UIImagePickerControllerSourceType.SavedPhotosAlbum;
        imagePicker.mediaTypes = [kUTTypeImage];
        imagePicker.allowsEditing = false;
        imagePicker.delegate = self;

        if(UIDevice.currentDevice().userInterfaceIdiom == .Pad){ // on a tablet, the image picker is supposed to be in a popover
            let popRect: CGRect = buttonRect;
            let popover: UIPopoverController = UIPopoverController(contentViewController: imagePicker);
            popover.presentPopoverFromRect(popRect, inView: self.view, permittedArrowDirections: UIPopoverArrowDirection.Up, animated: true);
        }else{
            self.presentViewController(imagePicker, animated: true, completion: nil);
        }
    });

其他回答

我遇到过这个问题。当我们调用相机并释放视图时就产生了这个问题。举个例子,调用一个相机并在viewDidDisappear方法中设置视图为nil,这个错误将会出现,因为没有相机事件的回调。对于这个错误,也要确认一下。

这可能是内置ImagePickerController的错误。我的代码可以运行,但在iPhone 6 Plus上偶尔会崩溃。

我已经尝试了其他答案提出的所有解决方案,但都没有运气。问题最终解决后切换到JPSImagePickerController。

我使用Phonegap,但这个线程一直作为第一个当谷歌关于错误消息。

对我来说,通过将imagetype定义为PNG,这个问题就消失了。

encodingType : Camera.EncodingType.PNG

所以整条线是:

 navigator.camera.getPicture(successFunction, failFunction, { encodingType : Camera.EncodingType.PNG, correctOrientation:true, sourceType : Camera.PictureSourceType    .PHOTOLIBRARY, quality: 70, allowEdit : false , destinationType: Camera.DestinationType.DATA_URL});

你的里程可能会有所不同,但这对我来说很管用。

我在这个问题上挣扎了几个小时,我阅读了每一个相关的主题,发现这个错误是因为我的设备的隐私设置下,我的应用程序的摄像头访问被阻止了!!我从来没有拒绝访问相机,我不知道它是如何被阻止的,但这就是问题所在!

我得到了同样的错误,在控制台怒吼的消息,同时打开相机。

’对一个没有被渲染的视图进行快照会导致一个空快照。确保你的视图在快照之前或屏幕更新后至少渲染过一次。”

对我来说,问题是在信息中的捆绑显示名称。plist文件。它是空的某种方式,我把我的应用程序名称在那里,现在它工作正常。我没有收到任何相机权限警报,因为空的Bundle显示名称。它阻止了视图的呈现。

问题不在于视图,而在于未经许可而呈现视图。你可以检查设置>隐私>相机,如果你的应用程序没有列出,问题可能是一样的。