我需要编写代码来检查PHPhotoLibrary.authorizationStatus(),因为应用程序在这方面默默失败。将以下内容添加到AppDelegate.swift即可解决此问题(您需要导入Photos):
func applicationDidBecomeActive(_ application: UIApplication) {
photoLibraryAvailabilityCheck()
}
func photoLibraryAvailabilityCheck()
{
if PHPhotoLibrary.authorizationStatus() == PHAuthorizationStatus.authorized
{
}
else
{
PHPhotoLibrary.requestAuthorization(requestAuthorizationHandler)
}
}
func requestAuthorizationHandler(status: PHAuthorizationStatus)
{
if PHPhotoLibrary.authorizationStatus() == PHAuthorizationStatus.authorized
{
}
else
{
alertToEncouragePhotoLibraryAccessWhenApplicationStarts()
}
}
func alertToEncourageCameraAccessWhenApplicationStarts()
{
let internetUnavailableAlertController = UIAlertController (title: "Camera Unavailable", message: "Please check to see if it is disconnected or in use by another application", preferredStyle: .alert)
let settingsAction = UIAlertAction(title: "Settings", style: .destructive) { (_) -> Void in
let settingsUrl = NSURL(string:UIApplicationOpenSettingsURLString)
if let url = settingsUrl {
DispatchQueue.main.async {
UIApplication.shared.open(url as URL, options: [:], completionHandler: nil)
}
}
}
let cancelAction = UIAlertAction(title: "Okay", style: .default, handler: nil)
internetUnavailableAlertController .addAction(settingsAction)
internetUnavailableAlertController .addAction(cancelAction)
self.window?.rootViewController!.present(internetUnavailableAlertController , animated: true, completion: nil)
}
func alertToEncouragePhotoLibraryAccessWhenApplicationStarts()
{
let cameraUnavailableAlertController = UIAlertController (title: "Photo Library Unavailable", message: "Please check to see if device settings doesn't allow photo library access", preferredStyle: .alert)
let settingsAction = UIAlertAction(title: "Settings", style: .destructive) { (_) -> Void in
let settingsUrl = NSURL(string:UIApplicationOpenSettingsURLString)
if let url = settingsUrl {
UIApplication.shared.open(url as URL, options: [:], completionHandler: nil)
}
}
let cancelAction = UIAlertAction(title: "Okay", style: .default, handler: nil)
cameraUnavailableAlertController .addAction(settingsAction)
cameraUnavailableAlertController .addAction(cancelAction)
self.window?.rootViewController!.present(cameraUnavailableAlertController , animated: true, completion: nil)
}
info[UIImagePickerControllerPHAsset]
是一个PHAsset
,它具有可以持久标识该对象的localIdentifier
。 - Martin R