Ios Firebase Swift 3使用NSURLSession将配置文件图像加载到TableView中
我按照教程加载图像URL并将其附加到数组中，以在每个用户的单元格的UITableView中显示用户配置文件图像，使用以下代码块：Ios Firebase Swift 3使用NSURLSession将配置文件图像加载到TableView中,ios,uitableview,firebase,swift3,nsurlsession,Ios,Uitableview,Firebase,Swift3,Nsurlsession,我按照教程加载图像URL并将其附加到数组中，以在每个用户的单元格的UITableView中显示用户配置文件图像，使用以下代码块： let url = NSURL(string: urlString) NSURLSession.sharedSession().dataTaskWithURL(url!, completionHandler: { (data, response, error) in //download hit an error so lets re
let url = NSURL(string: urlString)
NSURLSession.sharedSession().dataTaskWithURL(url!, completionHandler: { (data, response, error) in
//download hit an error so lets return out
if error != nil {
print(error)
return
}
dispatch_async(dispatch_get_main_queue(), {
//"profilePics" is my array of UIImages made as a global var
self.profileImages.append(UIImage[data!])
})
}).resume()
但每次我运行它时，数据都会得到一个nil，它永远不会附加到我的数组中。有人能解释一下我遗漏了什么吗？这是我第一次尝试Firebase。我实际上发现了问题所在，我不想在其他人可能正在寻找相同问题的解决方案时删除帖子。事实证明，URLSession工作正常，所以找不到“NSURLSession”不是问题。然而，一旦我得到了工作的配置文件图像将只加载后重新加载我的uitableview。一旦我移动了tableview.reload（），它就会一直工作，下面是我的Swift 3工作代码：
//This method grabs all user data for each user & adds them to an
//array to be displayed in a uitableview
func getUsersData(){
FIRDatabase.database().reference().child("users").observe(.childAdded, with: {(snapshot) in
if let dictionary = snapshot.value as? [String:AnyObject]{
print(snapshot.childrenCount)
if (snapshot.childrenCount > 2) {
self.users.append(dictionary["name"] as! String)
if !(dictionary["subjects"]?.isEqual(""))!{
self.subjects.append(dictionary["subjects"] as! String)
}
else{
self.subjects.append("N/A")
}
if !(dictionary["location"]?.isEqual(nil))!{
self.states.append(dictionary["location"] as! String)
}
else{
self.states.append("N/A")
}
self.ratings.append("4.1")
if let profileImageURL = dictionary["userPhoto"] {
let url = URL(string: profileImageURL as! String)
URLSession.shared.dataTask(with: url!, completionHandler: {(data, response, error) in
if error != nil{
print(error!)
return
}
DispatchQueue.main.async {
self.profilePics.append(UIImage(data: data!))
print("Image appended")
}
// This line is required to reload with new data in tableview array data from db
DispatchQueue.main.async{
self.browseUITableView.reloadData()
}
}).resume()
}
// grabbing images from db end
}
}
})
}
你为什么要向nsarray添加数据？这很糟糕practice@kirtimali你有什么建议？看看这个
//This method grabs all user data for each user & adds them to an
//array to be displayed in a uitableview
func getUsersData(){
FIRDatabase.database().reference().child("users").observe(.childAdded, with: {(snapshot) in
if let dictionary = snapshot.value as? [String:AnyObject]{
print(snapshot.childrenCount)
if (snapshot.childrenCount > 2) {
self.users.append(dictionary["name"] as! String)
if !(dictionary["subjects"]?.isEqual(""))!{
self.subjects.append(dictionary["subjects"] as! String)
}
else{
self.subjects.append("N/A")
}
if !(dictionary["location"]?.isEqual(nil))!{
self.states.append(dictionary["location"] as! String)
}
else{
self.states.append("N/A")
}
self.ratings.append("4.1")
if let profileImageURL = dictionary["userPhoto"] {
let url = URL(string: profileImageURL as! String)
URLSession.shared.dataTask(with: url!, completionHandler: {(data, response, error) in
if error != nil{
print(error!)
return
}
DispatchQueue.main.async {
self.profilePics.append(UIImage(data: data!))
print("Image appended")
}
// This line is required to reload with new data in tableview array data from db
DispatchQueue.main.async{
self.browseUITableView.reloadData()
}
}).resume()
}
// grabbing images from db end
}
}
})
}