如何解决如何使用重新加载项目而不是使用 firestore
我有一个聊天应用程序使用 Firestore，当一个新的 document or -> (message) 添加到 Firestore 我的 collectionView 重新加载所有数据，应用程序冻结一秒钟，直到所有数据重新加载，我不知道很多关于 collectionViews 但我认为如果没有错，这是因为 collectionView 试图计算每个单元格的大小，这是调试器消息
The relevant UICollectionViewFlowLayout instance is <UICollectionViewFlowLayout: 0x7fbd974b3c40>,and it is attached to <UICollectionView: 0x7fbd97930600; frame = (0 61; 414 663); clipsToBounds = YES; gestureRecognizers = <NSArray: 0x600002c5df20>; layer = <CALayer: 0x6000023f9640>; contentOffset: {-5,-5}; contentSize: {404,8}; adjustedContentInset: {5,5,5}; layout: <UICollectionViewFlowLayout: 0x7fbd974b3c40>; dataSource: <DELEVARE___ديليفري.DriverChat: 0x7fbd97843600>>.
2021-01-16 13:54:43.232052+0200 DELEVARE - ديليفري[51104:999159] Make a symbolic breakpoint at UICollectionViewFlowLayoutBreakForInvalidSizes to catch this in the debugger.
symbolic breakpoint at UICollectionViewFlowLayoutBreakForInvalidSizes to catch this in the debugger.
这个调试器消息在每个单元格加载到 collectionView 时被调用 repeated，这是我的 collectionView How to solve UICollectionViewFlowLayoutBreakForInvalidSizes
我不知道如何仅将新的附加项插入到 collectionView 中的数组中，我希望这只是像普通聊天应用程序一样做出反应。
我已经试过了
func getMessages(){
guard let uid = Auth.auth().currentUser?.uid else {return}
let firestore = Firestore.firestore()
let doc = firestore.collection("طلبات قيد العمل").whereField("driverUid",isEqualTo: uid)
doc.getDocuments { (query,err) in
if err != nil {
print(err?.localizedDescription ?? "")
}
for document in query!.documents{
let chatDoc = document.reference.collection("المحادثات")
chatDoc.addSnapshotListener { (querysnap,err) in
if err != nil {
print(err?.localizedDescription ?? "")
}
self.messages = []
for snap in querysnap!.documents{
let data = snap.data()
guard let message = data["message"] as? String else {return}
guard let senderid = data["senderID"] as? String else {return}
guard let timestamp = data["date"] as? Timestamp else {return}
let date = Date(timeIntervalSince1970: TimeInterval(timestamp.seconds))
if senderid == Auth.auth().currentUser?.uid{
let drivermessages = driverMessages(image: UIImage(),text: message,date: date,isSender: true,driverid: senderid)
// this line of code is doing the same as collectionView.reloadData()
self.collectionView?.performBatchUpdates({
let indexPath = IndexPath(row: self.comments.count,section: 0)
self.messages.append(drivermessages)
self.collectionView?.insertItems(at: [indexPath])
},completion: nil)
}else {
guard let message2 = data["message"] as? String else {return}
guard let senderid2 = data["senderID"] as? String else {return}
guard let timestamp2 = data["date"] as? Timestamp else {return}
guard let img = self.profileImg else {return}
let date2 = Date(timeIntervalSince1970: TimeInterval(timestamp2.seconds))
let usermessages = driverMessages(image: img,text: message2,date: date2,isSender: false,driverid: senderid2)
self.messages.append(usermessages)
self.collectionView?.performBatchUpdates({
let indexPath = IndexPath(row: self.comments.count,section: 0)
self.messages.append(usermessages)
self.collectionView?.insertItems(at: [indexPath])
},completion: nil)
}
}
}
}
}
}
这是我的代码
func getMessages(){
guard let uid = Auth.auth().currentUser?.uid else {return}
let firestore = Firestore.firestore()
let doc = firestore.collection("طلبات قيد العمل").whereField("driverUid",err) in
if err != nil {
print(err?.localizedDescription ?? "")
}
for document in query!.documents{
let chatDoc = document.reference.collection("المحادثات")
chatDoc.addSnapshotListener { (querysnap,driverid: senderid)
self.messages.append(drivermessages)
}else {
guard let message2 = data["message"] as? String else {return}
guard let senderid2 = data["senderID"] as? String else {return}
guard let timestamp2 = data["date"] as? Timestamp else {return}
guard let img = self.profileImg else {return}
let date2 = Date(timeIntervalSince1970: TimeInterval(timestamp2.seconds))
let usermessages = driverMessages(image: img,driverid: senderid2)
self.messages.append(usermessages)
}
DispatchQueue.main.async {
self.collectionView.reloadData()
let item = self.messages.count - 1
let insertionIndexPath = IndexPath(item: item,section: 0)
self.collectionView.scrollToItem(at: insertionIndexPath,at: .bottom,animated: true)
}
}
}
}
}
}
解决方法
我对自己编码很陌生。
但是，在我看来，让 .onSnapshot 侦听器查找 change 类型的 added 对您有帮助。
https://firebase.google.com/docs/reference/android/com/google/firebase/firestore/DocumentChange.Type
我发现这篇文章对我正在处理的 CRUD 应用程序非常有帮助：
https://bezkoder.com/react-hooks-firestore/
其中一部分展示了如何监听各种类型的变化。 我能够在我的应用程序中实现它以仅返回添加的文档而不是整个集合，然后将其附加到我的数组中。
tutorialsRef.onSnapshot(function(snapshot) {
snapshot.docChanges().forEach(function(change) {
if (change.type === "added") {
console.log("New tutorial: ",change.doc.data());
}
if (change.type === "modified") {
console.log("Modified tutorial: ",change.doc.data());
}
if (change.type === "removed") {
console.log("Removed tutorial: ",change.doc.data());
}
});
});
版权声明：本文内容由互联网用户自发贡献，该文观点与技术仅代表作者本人。本站仅提供信息存储空间服务，不拥有所有权，不承担相关法律责任。如发现本站有涉嫌侵权/违法违规的内容， 请发送邮件至 dio@foxmail.com 举报，一经查实，本站将立刻删除。
