我目前正在开发一个库存应用程序，该应用程序将保存两个实体的信息。第一个实体拥有两个属性“站点名称”和“站点地址”。第二个实体持有“itemName”“itemQuantity”和“item picture”。我能够将数据保存到核心数据。我现在遇到了获取数据的问题。有没有人知道如何在视图控制器之间传递数据。
我正在上传网站视图控制器，详细视图控制器和我的新项目视图控制器。
class SiteTableViewController: UIViewController {
var managedContext : NSManagedObjectContext = CoreDataHelper.sharedInstance.myContext
var sites : [Site]? = [Site]()
//variable to hold selected site
var selectedSite : Site?
let myCellIdentifier = "cell"
@IBOutlet weak var tableView: UITableView!
override func viewDidLoad() {
super.viewDidLoad()
tableView.delegate = self
tableView.dataSource = self
// Do any additional setup after loading the view.
sites = [Site]()
reloadData()
automaticallyAdjustsScrollViewInsets = false
//let barButtonItem = UIBarButtonItem(barButtonSystemItem: .Compose, target: self, action: "addSite:")
//self.navigationItem.leftBarButtonItems = [barButtonItem]
}
//load new data into table
func reloadData() {
let fetchRequest = NSFetchRequest(entityName: "Site")
let sortDescriptor = NSSortDescriptor(key: "siteName", ascending: true)
fetchRequest.sortDescriptors = [sortDescriptor]
do {
sites = try self.managedContext.executeFetchRequest(fetchRequest) as! [Site]
tableView.reloadData()
} catch {
print("Error fetching objects")
}
tableView.reloadData()
}
override func viewWillAppear(animated: Bool) {
reloadData()
}
}
extension SiteTableViewController: UITableViewDataSource, UITableViewDelegate {
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier(myCellIdentifier, forIndexPath: indexPath)
let site = sites![indexPath.row]
cell.textLabel?.text = site.valueForKey("siteName") as? String
cell.detailTextLabel?.text = site.valueForKey("siteAddress") as? String
return cell
}
func tableView(tableView: UITableView, canEditRowAtIndexPath indexPath: NSIndexPath) -> Bool {
return true
}
func tableView(tableView: UITableView, commitEditingStyle editingStyle: UITableViewCellEditingStyle, forRowAtIndexPath indexPath: NSIndexPath) {
if editingStyle == .Delete {
let logItemToDelete = sites![indexPath.row]
sites?.removeAtIndex(indexPath.row)
managedContext.deleteObject(logItemToDelete)
do {
try managedContext.save()
} catch {
print("Could not save or delete object")
}
tableView.deleteRowsAtIndexPaths([indexPath], withRowAnimation: .Fade)
}
}
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return sites!.count
}
// func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
//
// selectedSite = sites![indexPath.row]
//
// }
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
if segue.identifier == "detailSegue" {
var nextVC = segue.destinationViewController as! DetailTableViewController
var selectedItem : Site = sites![self.tableView.indexPathForSelectedRow!.row] as Site
fetchSite = selectedItem.valueForKey("siteName") as? NSManagedObject
nextVC.valueToPass = selectedItem.siteName!
}
}
}
这是我的详细视图控制器
import UIKit
import CoreData
public var fetchSite : NSManagedObject?
class DetailTableViewController: UIViewController, UITableViewDelegate, UITableViewDataSource {
var holdSiteData: NSMutableArray = NSMutableArray()
var managedContext : NSManagedObjectContext = CoreDataHelper.sharedInstance.myContext
@IBOutlet weak var tableView: UITableView!
var sites : [Site]!
//string to hold fetchResults controll
//open string to hold siteName
var valueToPass = ""
override func viewDidLoad() {
super.viewDidLoad()
self.navigationItem.title = "\(valueToPass)"
// Do any additional setup after loading the view.
tableView.delegate = self
tableView.dataSource = self
automaticallyAdjustsScrollViewInsets = false
tableView.estimatedRowHeight = 75.0
tableView.rowHeight = UITableViewAutomaticDimension
retrieveItemRelationship()
}
override func viewWillAppear(animated: Bool) {
retrieveItemRelationship()
}
func retrieveItemRelationship() {
// fetchSite.setValue(NSSet(keyCommands), forKey: "test")
let fetchRequest = NSFetchRequest(entityName: "SiteItem")
let sortDescriptors = NSSortDescriptor(key: "itemName", ascending: true)
fetchRequest.sortDescriptors = [sortDescriptors]
do {
let result = try fetchSite?.managedObjectContext?.executeRequest(fetchRequest)
} catch let error as NSError {
print(error)
}
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("cell", forIndexPath: indexPath) as! TableViewCell
// let cellInfo = fetchedResultsController.objectAtIndexPath(indexPath) as! SiteInfo
cell.cellName?.text = "Test"
return cell
}
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return holdSiteData.count
}
}
这是我保存数据的最后一个视图。我想我需要在这里传递数据，然后关联这两个实体，以便我可以正确保存它。例如，站点名称“Staples Center”。我需要将其拉到最终视图控制器，然后将信息保存到此对象。
import UIKit
import CoreData
class ItemNewViewController: UIViewController, UIPickerViewDataSource, UIPickerViewDelegate, UIImagePickerControllerDelegate, UINavigationControllerDelegate {
//var managedObjectContext : NSManagedObjectContext!
var managedContext : NSManagedObjectContext = CoreDataHelper.sharedInstance.myContext
//categories array for picker view
var categories = ["Building Materials", "Electrical", "Cleaning Products",
"Tools & Hardware", "Plumbing", "Paint", "Appliances", "Other"]
//textFields
@IBOutlet weak var itemNameTextField: UITextField!
@IBOutlet weak var quantityTextField: UITextField!
@IBOutlet weak var imageView: UIImageView!
//Label properties
@IBOutlet weak var newItemLabel: UILabel!
@IBOutlet weak var quantityLabel: UILabel!
@IBOutlet weak var categoryLabel: UILabel!
//pickerLabel
@IBOutlet weak var pickerListIcon: UIPickerView!
//clicker property label and textlabel for number
@IBOutlet weak var increaseNumberClicker: UIStepper!
@IBOutlet weak var numberFieldClicker: UITextField!
override func viewDidLoad() {
super.viewDidLoad()
//label property customize view code
newItemLabel.layer.masksToBounds = true
newItemLabel.layer.borderWidth = 2.0
newItemLabel.layer.borderColor = UIColor.whiteColor().CGColor
newItemLabel.layer.cornerRadius = 6
//label property customize view code
quantityLabel.layer.masksToBounds = true
quantityLabel.layer.borderWidth = 2.0
quantityLabel.layer.borderColor = UIColor.whiteColor().CGColor
quantityLabel.layer.cornerRadius = 6
//lable property customize view code
categoryLabel.layer.masksToBounds = true
categoryLabel.layer.borderWidth = 3.0
categoryLabel.layer.borderColor = UIColor.whiteColor().CGColor
categoryLabel.layer.cornerRadius = 6
//label picker customize view
pickerListIcon.layer.masksToBounds = true
pickerListIcon.layer.borderWidth = 3.0
pickerListIcon.layer.borderColor = UIColor.whiteColor().CGColor
pickerListIcon.layer.cornerRadius = 6
pickerListIcon.layer.backgroundColor = UIColor.blackColor().CGColor
self.pickerListIcon.dataSource = self
self.pickerListIcon.delegate = self
numberFieldClicker.enabled = false
//UIStepper value
increaseNumberClicker.wraps = true
increaseNumberClicker.autorepeat = true
increaseNumberClicker.layer.masksToBounds = true
increaseNumberClicker.layer.borderWidth = 3.0
increaseNumberClicker.layer.borderColor = UIColor.whiteColor().CGColor
increaseNumberClicker.layer.cornerRadius = 6
increaseNumberClicker.layer.backgroundColor = UIColor.blackColor().CGColor
//below code declares a variable that inherits from UITapGesture
//this allows the image view to be an action
//*Make sure you enable user interaction in storyBoard very IMPORTANT!
let imageTapRecognizer = UITapGestureRecognizer(target: self, action: "enableImage")
self.imageView.addGestureRecognizer(imageTapRecognizer)
}
// below function allows the camera view to be accessible
func enableImage(){
if UIImagePickerController.isSourceTypeAvailable(UIImagePickerControllerSourceType.Camera) {
let cameraView = UIImagePickerController()
cameraView.sourceType = UIImagePickerControllerSourceType.Camera
cameraView.delegate = self
self.presentViewController(cameraView, animated: true, completion: nil)
}
}
func imagePickerController(picker: UIImagePickerController, didFinishPickingImage image: UIImage, editingInfo: [String : AnyObject]?) {
self.imageView.image = image
picker.dismissViewControllerAnimated(true, completion: nil)
}
//function used to increase UIStepper. increment by integers of one
@IBAction func clickerIncreaser(sender: UIStepper) {
numberFieldClicker.text = Int(sender.value).description
}
func numberOfComponentsInPickerView(pickerView: UIPickerView) -> Int {
return 1
}
func pickerView(pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
return categories.count
}
func pickerView(pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
return categories[row]
}
func pickerView(pickerView: UIPickerView, attributedTitleForRow row: Int, forComponent component: Int) -> NSAttributedString? {
//passing the categorories array into the new constant myCategoriesArray
let myCategoriesArray = categories[row]
let myTextColor = NSAttributedString(string: myCategoriesArray, attributes: [NSForegroundColorAttributeName: UIColor.whiteColor()])
return myTextColor
}
//save data to core data
@IBAction func saveButton(sender: AnyObject) {
if (itemNameTextField.text?.isEmpty)! {
let displayAlertController = UIAlertController(title: "Form Incomplete", message: "Please provide item with a name", preferredStyle: .Alert)
let okButton : UIAlertAction = UIAlertAction(title: "OK", style: .Default, handler: nil)
displayAlertController.addAction(okButton)
self.presentViewController(displayAlertController, animated: true, completion: nil)
} else {
//declare site object and object
let siteInfoEntity = NSEntityDescription.entityForName("SiteItem", inManagedObjectContext: self.managedContext)
//declare item and item object
let siteObject = SiteItem(entity: siteInfoEntity!, insertIntoManagedObjectContext: self.managedContext)
//convert String to Integer
let quantityNumber: Int? = Int(quantityTextField.text!)
siteObject.setValue(itemNameTextField.text?.capitalizedString, forKey: "itemName")
siteObject.setValue(quantityNumber, forKey: "itemQnty")
fetchSite?.setValue(NSSet(object: siteObject), forKey: "reverseItems")
self.managedContext.saveOrLogError()
self.navigationController?.popViewControllerAnimated(true)
}
}
}
再一次，如果有人可以指出我正确的方向来保存我与核心数据的关系，那么检索这些关系会很棒。核心数据还是新手，所以需要我能得到的所有帮助！
谢谢
答案 0 :(得分：0)
您的详细信息控制器可以拥有属性Site。在prepareForSegue中，您将选定的Site对象传递给详细控制器。
网站列表和项目列表都应该由NSFetchedResultsController支持，而不是内存数组。