我一直在关注制作一个instragram-esque应用程序的教程,我在查找如何从Firebase和Feed中删除帖子时遇到了很多麻烦.使用此功能将用户选择或拍摄的图像上传到Firebase数据库：
func uploadToFirebase() {
AppDelegate.instance().showActivityIndicator()
let uid = FIRAuth.auth()!.currentUser!.uid
let ref = FIRDatabase.database().reference()
let storage = FIRStorage.storage().reference(forURL: "gs://cloudcamerattt.appspot.com")
let key = ref.child("posts").childByAutoId().key
let imageRef = storage.child("posts").child(uid).child("\(key).jpg")
let data = UIImageJPEGRepresentation(self.previewImage.image!,0.6)
let uploadTask = imageRef.put(data!,Metadata: nil) { (Metadata,error) in
if error != nil {
print(error!.localizedDescription)
AppDelegate.instance().dismissActivityIndicator()
return
}
imageRef.downloadURL(completion: { (url,error) in
if let url = url {
// how do I add date: NSDate in here?
let Feed = ["userID" : uid,"pathToImage" : url.absoluteString,"likes" : 0,"author" : FIRAuth.auth()!.currentUser!.displayName!,"postID" : key] as [String : Any]
let postFeed = ["\(key)" : Feed]
ref.child("posts").updateChildValues(postFeed)
AppDelegate.instance().dismissActivityIndicator()
self.dismiss(animated: true,completion: nil)
}
})
}
uploadTask.resume()
}
最终在Firebase中看起来像这样：
在我发现堆栈溢出答案之后,我尝试设置一个删除按钮时按下删除按钮的功能.此删除按钮位于“照片详细信息”视图中,用户通过点击图像Feed中的图像来访问该视图 – 此照片详细信息视图以更大的尺寸显示图像,以及其他一些信息,例如：
func deletePost(firstTree: String,childIWantToRemove: String) {
let uid = FIRAuth.auth()!.currentUser!.uid
let ref = FIRDatabase.database().reference()
let storage = FIRStorage.storage().reference(forURL: "gs://cloudcamerattt.appspot.com")
let key = ref.child("posts").childByAutoId().key
let imageRef = storage.child("posts").child(uid).child("\(key).jpg")
ref.child("posts").child(key).child("postID").removeValue { (error,ref) in
if error != nil {
print("error \(error)")
}
}
}
@IBAction func moreButtonPressed(_ sender: AnyObject) {
let alertController = UIAlertController(title: nil,message: nil,preferredStyle: .actionSheet)
let cancelAction = UIAlertAction(title: "Cancel",style: .cancel)
let destroyAction = UIAlertAction(title: "Delete",style: .destructive) { action in
print(action)
let ref = FIRDatabase.database().reference()
let key = ref.child("posts").childByAutoId().key
let firstTree = key
let valueToRemove = "postID"
self.deletePost(firstTree: firstTree,childIWantToRemove: valueToRemove)
}
alertController.addAction(destroyAction)
alertController.addAction(cancelAction)
self.present(alertController,animated: true)
}
我不是真的在理解我在做什么,不用说点击删除按钮基本上没什么.任何人都可以告诉我如何修复删除功能,以便我可以正确删除firebase中的图像/帖子？
编辑：我有var selectedPost：发布！在我的PhotoDetailController中,它从didSelectItem中的FeedViewController(图像提要)传递,如下所示：
func collectionView(_ collectionView: UICollectionView,didSelectItemAt indexPath: IndexPath) {
let photoDetailController = self.storyboard?.instantiateViewController(withIdentifier: "photoDetail") as! PhotoDetailController
photoDetailController.selectedPost = posts[indexPath.row]
present(photoDetailController,animated: true,completion: nil)
}
所以它有索引路径.关于上述函数的另一个注意事项是var posts = [Post]()在FeedViewController中实例化,因此post [indexPath.row]来自.
解决方法
这应该工作.
func deletePost() {
let uid = FIRAuth.auth()!.currentUser!.uid
let storage = FIRStorage.storage().reference(forURL: "gs://cloudcamerattt.appspot.com")
// Remove the post from the DB
ref.child("posts").child(selectedPost.postID).removeValue { error in
if error != nil {
print("error \(error)")
}
}
// Remove the image from storage
let imageRef = storage.child("posts").child(uid).child("\(selectedPost.postID).jpg")
imageRef.delete { error in
if let error = error {
// Uh-oh,an error occurred!
} else {
// File deleted successfully
}
}
}
