[英]UITableView not being updated after adding new items (using Core Data)
[英]Core data not being updated after managedContext.save but no errors thrown
我正在嘗試更新Core數據中已保存的條目,objectContext不是nil也不是managedObject。 使用所述Id將新值設置為managedObject。 調用managedContext.save()時不會拋出任何錯誤,但coreData中沒有反映任何更改
我已經嘗試使用setValue()無效,我已經在谷歌和堆棧溢出搜索類似的問題,大多數時候它說,托管對象是零。
var taskName:String!
var resultsController: NSFetchedResultsController<Tasks>!
// MARK: - Properties
// Manage objects and update tasks
//var resultsController: NSFetchedResultsController<Tasks>!
var managedContext: NSManagedObjectContext!
var tasksArray = [NSManagedObject]()
var fetchRequest = NSFetchRequest<NSFetchRequestResult>(entityName: "Tasks")
func settextfields() {
let res = resultsController.fetchedObjects!
print(res)
for r in res {
if r.name == taskName {
txt_name.text = "\(r.name ?? "Task name" )"
txt_date.text = "\(r.date ?? "Task date")"
segmentedBtn.selectedSegmentIndex = Int(r.priority)
}
}
}
func loadTable() {
let request: NSFetchRequest<Tasks> = Tasks.fetchRequest()
// Sort by date
let sortDescriptor = NSSortDescriptor(key: "date", ascending: true)
request.sortDescriptors = [sortDescriptor]
resultsController = NSFetchedResultsController(fetchRequest: request, managedObjectContext: coreData.managedContext, sectionNameKeyPath: nil, cacheName: nil)
// Fetch data
do {
try resultsController.performFetch()
print("Fetch successful")
} catch {
print("Error performing fetch: \(error)")
}
}
@IBAction func saveEdit(_ sender: Any) {
guard let name = txt_name.text, !name.isEmpty else {
return
}
guard let date = txt_date.text, !date.isEmpty else {
return
}
do {
loadTable()
let res = resultsController.fetchedObjects!
for r in res {
i += 1
if r.name == taskName {
print(r)
guard let name = txt_name.text, !name.isEmpty else {
return
}
guard let date = txt_date.text, !date.isEmpty else {
return
}
do {
r.name = name
r.date = date
r.priority = Int16(segmentedBtn.selectedSegmentIndex)
}
do {
try managedContext.save()
print(managedContext, r)
dismiss(animated: true)
print("Edit Successful!")
} catch {
print("Error saving task: \(error)")
}
}
}
}
我實際上使用謂詞重寫了保存函數,就像上面提到的人一樣,並且它有效。 然后我將一個viewWillLoad添加到mainViewController,以便在更新條目后重新加載tableView
@IBAction func saveEdit(_ sender: Any) {
guard let name = txt_name.text, !name.isEmpty else {
return
}
guard let date = txt_date.text, !date.isEmpty else {
return
}
do {
let fetchRequest:NSFetchRequest<NSFetchRequestResult> = NSFetchRequest.init(entityName: "Tasks")
fetchRequest.predicate = NSPredicate(format: "name = %@", taskName)
let test = try managedContext.fetch(fetchRequest)
let obj = test[0] as! NSManagedObject
obj.setValue(name, forKey: "name")
obj.setValue(date, forKey: "date")
obj.setValue(Int16(segmentedBtn.selectedSegmentIndex), forKey: "priority")
do {
try managedContext.save()
dismiss(animated: true)
print("Edit Successful!")
} catch {
print("Error saving task: \(error)")
}
} catch {
print(error)
}
}
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