Ios 在不同CollectionViewCell之间传递数据
我想将数据从FeedCollectionViewCell传递到另一个ChatViewController 内部馈送视图控制器Ios 在不同CollectionViewCell之间传递数据,ios,swift,firebase,firebase-realtime-database,Ios,Swift,Firebase,Firebase Realtime Database,我想将数据从FeedCollectionViewCell传递到另一个ChatViewController 内部馈送视图控制器 func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell{ let cell = collectionView.dequeueReusableCell(withReuseIdentifier:
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell{
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: cellIdentifier, for: indexPath) as! FeedCollectionViewCell
cell.postTextView.text = posts.reversed()[indexPath.row].caption
cell.postImageView.image = UIImage(named: "photoplaceholder.jpg")
cell.priceTextView.text = posts.reversed()[indexPath.row].price
cell.categoryTextView.text = posts.reversed()[indexPath.row].category
cell.usernameLabel.text = posts.reversed()[indexPath.row].username
cell.buttonEvents = {
let storyboard = UIStoryboard(name: "Main" , bundle: nil)
let chatViewController =
storyboard.instantiateViewController(withIdentifier: "chat")
self.present(chatViewController, animated: true,completion: nil)
var receiverIDNumber = cell.usernameLabel.text
}
//我想将receiverIDNumber传递给ChatViewController
ChatViewController内部:
func sendDataToDatabase(message: String){
let ref = Database.database().reference()
let senderIDNumber = Auth.auth().currentUser?.uid
**//I want receiverIDNumber to be the data that is passed from FeedViewController**
let receiverIDNumber = "21"
let postsReference = ref.child("chats")
let newPostId = postsReference.childByAutoId().key
let newPostReference = postsReference.child(newPostId)
newPostReference.setValue(["message" : messageText.text!, "senderID" : senderIDNumber, "receiverID" : receiverIDNumber], withCompletionBlock: {
(error, ref) in
if error != nil {
return
}
})
}
我正在尝试从FeedCollectionViewCell获取receiverIDNumber(将接收消息的用户)
对于MainViewController中的cell.buttonEvents,它将打开ChatViewController
干管的型号如下所示:
class Post{
var caption: String
var photoUrl: String
var price: String
var category: String
var username: String
var pic: String
init(captionText: String, photoUrlString: String, priceText: String, categoryText: String, usernameLabel: String, profileImageURL: String){
caption = captionText
photoUrl = photoUrlString
price = priceText
category = categoryText
username = usernameLabel
pic = profileImageURL
}
例如,在一个单元格中,userprofileimage旁边有一个按钮,人们可以单击该按钮与用户聊天。单击该按钮后,它会将用户引导到ChatViewController。在ChatViewController中,我使用了不同的模型:
class Chat {
var message: String
var senderID: String
var receiverID: String
init(messageTextString: String, senderIDNumber: String, receiverIDNumber: String){
message = messageTextString
senderID = senderIDNumber
receiverID = receiverIDNumber
}
由于receiverIDNumber(receiverUsername)来自ChatCollectionView,我发现很难将其与Main中的username进行协调。首先,向您的
ChatViewController
类添加一个变量:
class ChatViewController: UIViewController {
var username: String = ""
override func viewDidLoad() {
super.viewDidLoad()
// Check if userID has been given a value
if !username.isEmpty {
// Do stuff here with username
}
}
}
然后,可以在实例化视图控制器后为其指定一个值。我已将其放入didSelectRow
方法中,因此当选择单元格时,将显示新的视图控制器。您仍然需要使用cellForItemAt
方法创建每个单元格
override func collectionView(collectionView: UICollectionView, didSelectItemAtIndexPath indexPath: IndexPath) {
let storyboard = UIStoryboard(name: "Main" , bundle: nil)
let chatViewController = storyboard.instantiateViewController(withIdentifier: "chat")
// Here is the important bit
chatViewController.username = posts.reversed()[indexPath.row].username
// Present view controller
self.present(chatViewController, animated: true,completion: nil)
}
请注意:
- 不要在
方法中执行任何操作、查看控制器演示文稿等。每次重新绘制集合视图时,系统都会为每个项目调用它,因此这将是一种混乱。它仅用于设置每个单元格的外观cellForItemAt
- 创建一个新的反向posts数组,而不是每次需要时都将其反转:
let reversedPosts=posts.reversed()
- 我不确定你的
按钮按钮是做什么的。这是按下按钮时调用的闭合吗?这就是为什么我选择在选择单元格时显示新的视图控制器
- 您还可以使用自定义序列图像板序列执行此操作,并使用以下方法:
显示新的视图控制器,以及performsgue
在新视图控制器显示之前将数据发送到新视图控制器。这将代替prepareforsgue
等self.present()