下载图像,然后从 Firebase 缓存它 Swift 3
Downloading Image, then Cache it from Firebase Swift 3
我目前正在尝试设置用户个人资料图片。我让用户拍了一张上传到 Firebase 的图片,但我想下载该图片并缓存它。我现在在下载它时遇到问题,在我修复之后我会担心缓存它。
// Uploading Images to Firebase
func uploadImageToFirebaseStorage(data: NSData ) {
let storageRef = FIRStorage.storage().reference(withPath: "myPics/profilePic.jpg")
let uploadMetaData = FIRStorageMetadata()
uploadMetaData.contentType = "image/jpeg"
let uploadTask = storageRef.put(data as Data, metadata: uploadMetaData) { (metadata, error) in
if (error != nil) {
print("I Received an error \(error?.localizedDescription)")
} else {
print("Upload Complete! Here is the MetaData \(metadata?.downloadURL())")
}
}
现在我在使用 Issue Navigator 时遇到的问题:
它在 reference = self.storage
上有这个问题。提前致谢!
//Download Image for User Profile Picture
func downloadImageUserFromFirebase() {
let storage = FIRStorage.storage()
var reference: FIRStorageReference!
reference = self.storage.referenceForURL("gs:URL.appspot.com")
reference.downloadURL { (url, error) in
let data = NSData(contentsOf: url!)
let image = UIImage(data: data! as Data)
self.profileImageView.image = image
}
}
存储未声明为 class 的 属性,它是在该方法中声明的。此外,即使它被声明为 class 的 属性,在 swift 中,您也不再需要将 self 放在 class 属性 之前除非你在闭包中。
要么:
func downloadImageUserFromFirebase() {
let storage = FIRStorage.storage()
var reference: FIRStorageReference!
//all I did here was remove self before storage
reference = storage.referenceForURL("gs:URL.appspot.com")
reference.downloadURL { (url, error) in
let data = NSData(contentsOf: url!)
let image = UIImage(data: data! as Data)
self.profileImageView.image = image
}
}
或者,理想情况下,重构代码:
class ProfileViewController: UIViewController {
//here we are initializing it as a property of the class
let storage = FIRStorage.storage()
func downloadImageUserFromFirebase() {
var reference: FIRStorageReference = storage.referenceForURL("gs:URL.appspot.com")
reference.downloadURL { (url, error) in
//using a guard statement to unwrap the url and check for error
guard let imageURL = url, error == nil {
//handle error here if returned url is bad or there is error
return
}
guard let data = NSData(contentsOf: imageURL) else {
//same thing here, handle failed data download
return
}
let image = UIImage(data: data)
self.profileImageView.image = image
}
}
}
reference.downloadurl 将识别当前用户的图像,或者我们应该将 profileimageurl 保存在数据库中
我目前正在尝试设置用户个人资料图片。我让用户拍了一张上传到 Firebase 的图片,但我想下载该图片并缓存它。我现在在下载它时遇到问题,在我修复之后我会担心缓存它。
// Uploading Images to Firebase
func uploadImageToFirebaseStorage(data: NSData ) {
let storageRef = FIRStorage.storage().reference(withPath: "myPics/profilePic.jpg")
let uploadMetaData = FIRStorageMetadata()
uploadMetaData.contentType = "image/jpeg"
let uploadTask = storageRef.put(data as Data, metadata: uploadMetaData) { (metadata, error) in
if (error != nil) {
print("I Received an error \(error?.localizedDescription)")
} else {
print("Upload Complete! Here is the MetaData \(metadata?.downloadURL())")
}
}
现在我在使用 Issue Navigator 时遇到的问题:
它在 reference = self.storage
上有这个问题。提前致谢!
//Download Image for User Profile Picture
func downloadImageUserFromFirebase() {
let storage = FIRStorage.storage()
var reference: FIRStorageReference!
reference = self.storage.referenceForURL("gs:URL.appspot.com")
reference.downloadURL { (url, error) in
let data = NSData(contentsOf: url!)
let image = UIImage(data: data! as Data)
self.profileImageView.image = image
}
}
存储未声明为 class 的 属性,它是在该方法中声明的。此外,即使它被声明为 class 的 属性,在 swift 中,您也不再需要将 self 放在 class 属性 之前除非你在闭包中。
要么:
func downloadImageUserFromFirebase() {
let storage = FIRStorage.storage()
var reference: FIRStorageReference!
//all I did here was remove self before storage
reference = storage.referenceForURL("gs:URL.appspot.com")
reference.downloadURL { (url, error) in
let data = NSData(contentsOf: url!)
let image = UIImage(data: data! as Data)
self.profileImageView.image = image
}
}
或者,理想情况下,重构代码:
class ProfileViewController: UIViewController {
//here we are initializing it as a property of the class
let storage = FIRStorage.storage()
func downloadImageUserFromFirebase() {
var reference: FIRStorageReference = storage.referenceForURL("gs:URL.appspot.com")
reference.downloadURL { (url, error) in
//using a guard statement to unwrap the url and check for error
guard let imageURL = url, error == nil {
//handle error here if returned url is bad or there is error
return
}
guard let data = NSData(contentsOf: imageURL) else {
//same thing here, handle failed data download
return
}
let image = UIImage(data: data)
self.profileImageView.image = image
}
}
}
reference.downloadurl 将识别当前用户的图像,或者我们应该将 profileimageurl 保存在数据库中