iOS 7 UIImagePickerController Camera No Image

Question

For some reason the first time I open the UIImagePickerController in camera mode on my app it comes up blank. I have to close and reopen that view to get the ca

Answer 1

In iOS 7, an app could access the camera before getting authorize of the user. When an app accesses the camera the first time, iOS show an alert view to ask user. Users could also set the authorize in Settings--Privacy--Camera--[Your app's name].

The camera will stay in a black blank view if the switch is off.

1. If you call the camera by using AVCaptureDeviceInput, you can check like:

   NSError *inputError = nil;
   AVCaptureDeviceInput *captureInput =
       [AVCaptureDeviceInput deviceInputWithDevice:inputDevice error:&inputError];
   if (inputError &&
       inputError.code == AVErrorApplicationIsNotAuthorizedToUseDevice)
   {
       // not authorized
   }
   

2. If you call by using UIImagePickerController, I am still looking for a way to check whether got the authorize.

   I tried these two methods:

   [UIImagePickerController isSourceTypeAvailable:]
   [UIImagePickerController isCameraDeviceAvailable:]
   

   but they did't work that they all returned YES.

UPDATE

Thanks for Scott's expanding. [AVCaptureDevice authorizationStatusForMediaType:] is a better way to check.

AVAuthorizationStatus authStatus = [AVCaptureDevice authorizationStatusForMediaType:AVMediaTypeVideo];
if (authStatus == AVAuthorizationStatusAuthorized) {
    // successful
} else {
    // failed, such as
    // AVAuthorizationStatusNotDetermined
    // AVAuthorizationStatusRestricted
    // AVAuthorizationStatusNotDetermined
}

But remember to check the iOS version, because [AVCaptureDevice authorizationStatusForMediaType:] and AVAuthorizationStatus are available above iOS 7.

if ([[[UIDevice currentDevice] systemVersion] floatValue] >= 7.0) {
    // code for AVCaptureDevice auth checking
}