我正在制作一个 4Chanesque 回复 View Controller 。我的计划是允许用户在 textView 中写回复。然后回复按钮应该获取他们的文本并将其添加到 Post 类中称为“comment”的字符串数组中。然后 tableView 将在该帖子的评论部分底部显示他们的评论。
这是我的评论 View Controller :
import Foundation
import UIKit
import Firebase
class MainTextView: UIViewController, UITextViewDelegate {
@IBOutlet weak var titleText: UILabel!
@IBOutlet weak var mainText: UILabel!
@IBOutlet weak var commentPlaceHolder: UILabel!
@IBOutlet weak var newCommentLabel: UITextView!
weak var delegate:NewPostVCDelegate?
@IBAction func reply(_ sender: UIButton) {
// Firebase code here
let postRef = Database.database().reference().child("posts").childByAutoId()
let postObject = [
"comment": newCommentLabel.text,
"timestamp": [".sv": "timestamp"]
] as [String : Any]
postRef.setValue(postObject, withCompletionBlock: { error, ref in
if error == nil {
self.delegate!.didUploadPost(withID: ref.key!)
self.dismiss(animated: true, completion: nil)
} else {
// Handle error
}
})
newCommentLabel.text = String()
commentPlaceHolder.isHidden = false
}
var post: Post?
作为引用,这是我的 Post 类
import Foundation
class Post {
var id:String
var title: String
var text:String
var createdAt:Date
var comment: [String] = []
init(id: String, title: String,text:String, timestamp:Double, comment: [String] = []) {
self.id = id
self.title = title
self.text = text
self.createdAt = Date(timeIntervalSince1970: timestamp / 1000)
}
static func parse(_ key:String, data:[String:Any]) -> Post? {
if let title = data["text"] as? String,
let text = data["title"] as? String,
let timestamp = data["timestamp"] as? Double {
return Post(id: key, title: title, text: text, timestamp:timestamp, comment: [])
}
return nil
}
}
NewPostVCDelegate 在我的 NewPostViewController 中这样声明:
protocol NewPostVCDelegate: class {
func didUploadPost(withID id:String)
}
我想知道当我真的只想在现有帖子中添加评论时,委托(delegate)是否让我尝试发表新帖子。我不确定如何以编程方式纠正此问题。目前,当我按下回复按钮时,我收到一条崩溃消息。它显示:“线程 1: fatal error :在展开可选值时意外发现 nil”。此错误消息红色突出显示行:“self.delegate!.didUploadPost(withID: ref.key!)”。感谢您的帮助。
最佳答案
既然崩溃就在这里
self.delegate!.didUploadPost(withID: ref.key!)
你的委托(delegate)是nil
,你需要在这里设置它destination.delegate = self
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
tableView.deselectRow(at: indexPath, animated: true)
if let destination = storyboard?.instantiateViewController(withIdentifier:"MainTextView") as? MainTextView {
destination.post = posts[indexPath.row]
destination.delegate = self
navigationController?.pushViewController(destination, animated: true)
}
}
关于ios - 回复按钮导致崩溃,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/56628629/