[swift] CoreData (2) 新增,刪除CoreData資料

這邊做個簡單的介面,讓TableView的資料來自資料庫,並能把資料存到資料庫裡面

首先先把TableView的資料來源設定成來自資料庫,完整程式碼如下,這樣就已經把Table的datasource friends來源改成SQLite了 ```swift
import UIKit
import CoreData
class ViewController: UIViewController , UITableViewDelegate , UITableViewDataSource, NSFetchedResultsControllerDelegate{
@IBOutlet weak var tableview: UITableView!
var friends : [Friend] = []
var fetchRequestController:NSFetchedResultsController!
override func viewDidLoad() {

  super.viewDidLoad()
  //讀取Friend的Entity
  var fetchRequest = NSFetchRequest(entityName: "Friend")
  //排序方式用name這個欄位
  let sortDescriptor = NSSortDescriptor(key: "name", ascending: true)
  fetchRequest.sortDescriptors = [sortDescriptor]
  if let managedObjectContext = (UIApplication.sharedApplication().delegate as AppDelegate).managedObjectContext{
      fetchRequestController = NSFetchedResultsController(fetchRequest: fetchRequest, managedObjectContext: managedObjectContext, sectionNameKeyPath: nil, cacheName: nil)
      //delegate設定為自己時,當新增修改刪除SQLite的資料時會呼叫以下事件
      //controllerWillChangeContent()
      //controller(_:didChangeObject:atIndexPath:forChangeType:newIndexPath:)
      //controllerDidChangeContent(_:)
      fetchRequestController.delegate = self
      var e:NSError?
      var result = fetchRequestController.performFetch(&e)
      friends = fetchRequestController.fetchedObjects as [Friend]
      if result != true{
           println(e?.localizedDescription)
      }
  }

}

  override func didReceiveMemoryWarning() {
  super.didReceiveMemoryWarning()
  // Dispose of any resources that can be recreated.

}

  func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
  let identifier = "cell"
  var cell = tableView.dequeueReusableCellWithIdentifier(identifier) as customCell
  cell.nameLabel.text = friends[indexPath.row].name
  cell.telLabel.text = friends[indexPath.row].tel.stringValue
  cell.picImageView.image = UIImage(data: friends[indexPath.row].picture)
  cell.marryLabel.text = friends[indexPath.row].marry.boolValue ? "YES" : "NO"
  return cell

}

  func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
  return friends.count

}
}


*   接著寫按下save後的事件將檔案能寫到資料庫中,在這之前先處理Yes and no的按鈕和載入圖片按鈕
Yes and No按鈕 ```swift
@IBOutlet weak var YesButton: UIButton!
    @IBOutlet weak var NoButton: UIButton!

        @IBAction func MarryButtonClick(sender: AnyObject) {
        YesButton.backgroundColor = (sender as UIButton == YesButton) ? UIColor.redColor() : UIColor.lightGrayColor()
        NoButton.backgroundColor = (sender as UIButton == NoButton) ? UIColor.redColor() : UIColor.lightGrayColor()
    }

實作載入圖片的按鈕,需要讓viewController實作UIImagePickerControllerDelegate和UINavigationControllerDelegate

class ViewController: UIViewController , UITableViewDelegate , UITableViewDataSource, NSFetchedResultsControllerDelegate , UIImagePickerControllerDelegate,UINavigationControllerDelegate
{

    }

selectPicture的按鈕 ```swift
@IBAction func SelectPictureClick(sender: AnyObject) {
let imagePicker = UIImagePickerController()
imagePicker.allowsEditing = false
imagePicker.sourceType = UIImagePickerControllerSourceType.PhotoLibrary
imagePicker.delegate = self
//顯示挑選圖片的視窗
self.presentViewController(imagePicker, animated: true, completion: nil)
}
func imagePickerController(picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [NSObject : AnyObject]) {
PicImageView.image = info[UIImagePickerControllerOriginalImage] as? UIImage
PicImageView.contentMode = UIViewContentMode.ScaleAspectFill
PicImageView.clipsToBounds = true
//關閉挑選圖片的視窗
dismissViewControllerAnimated(true, completion: nil)
}

接著執行看看應該結果[![](http://1.bp.blogspot.com/-2NW3TefbDxE/VQK1HNE_8rI/AAAAAAAAEkw/l2v6Div6BYA/s400/test.gif)](http://1.bp.blogspot.com/-2NW3TefbDxE/VQK1HNE_8rI/AAAAAAAAEkw/l2v6Div6BYA/s1600/test.gif)
*   接著把Save按鈕按下後存到SQLite的事件寫好 ```swift
@IBAction func SaveClick(sender: AnyObject) {
        if let manageObjectContext = (UIApplication.sharedApplication().delegate as AppDelegate).managedObjectContext{
            var friend = NSEntityDescription.insertNewObjectForEntityForName("Friend", inManagedObjectContext: manageObjectContext) as Friend
            friend.name = NameTextField.text
            friend.tel = TelTextField.text.toInt()
            friend.marry = (YesButton.backgroundColor == UIColor.redColor()) ? true : false
            friend.picture = UIImagePNGRepresentation(PicImageView.image)
            var e:NSError?
            if manageObjectContext.save(&e) != true{
                println("error: \(e?.localizedDescription)")
                return
            }
        }
    }

接著執行看看會發現按了儲存按鈕後雖然存進資料庫了,但沒有讓TableView馬上連動顯示,必須重新開APP才會顯示在table上* 還記得之前有繼承NSFetchedResultsControllerDelegate嗎?這時候派上用場了,補上幾個事件讓他可以跟TableView連動吧 ```swift
//資料庫準備更新了
func controllerWillChangeContent(controller: NSFetchedResultsController) {
tableview.beginUpdates()
}
func controller(controller: NSFetchedResultsController, didChangeObject anObject: AnyObject, atIndexPath indexPath: NSIndexPath?, forChangeType type: NSFetchedResultsChangeType, newIndexPath: NSIndexPath?) {
switch type{
case .Insert:
tableview.insertRowsAtIndexPaths([newIndexPath!], withRowAnimation: UITableViewRowAnimation.Fade)
case .Delete:
tableview.deleteRowsAtIndexPaths([indexPath!], withRowAnimation: UITableViewRowAnimation.Fade)
case .Update:
tableview.reloadRowsAtIndexPaths([indexPath!], withRowAnimation: UITableViewRowAnimation.Fade)
default:
tableview.reloadData()
}
friends = controller.fetchedObjects as [Friend]
}
func controllerDidChangeContent(controller: NSFetchedResultsController) {
tableview.endUpdates()
}

接著再執行看看應該就可以看到他會馬上顯示了*   最後來個刪除吧！！這邊只舉例刪除該如何做,就不加到例子當中了 ```swift
if let manageObjectContext = (UIApplication.sharedApplication().delegate as AppDelegate).managedObjectContext{
            //簡單說就是挑出那個想刪除的物件
            var friendToDelete = self.fetchRequestController.objectAtIndexPath(NSIndexPath(index: 0)) as Friend
            //呼叫刪除方法把它丟進去
            manageObjectContext.deleteObject(friendToDelete)
            var e:NSError?
            //儲存
            if manageObjectContext.save(&e) != true{
                println("error: \(e?.localizedDescription)")
            }
        }

基本上有操作過.NET Entity物件的話,這邊的概念幾乎都雷同,最後補上完整的程式碼 ```swift
import UIKit
import CoreData
class ViewController: UIViewController , UITableViewDelegate , UITableViewDataSource, UINavigationControllerDelegate ,NSFetchedResultsControllerDelegate , UIImagePickerControllerDelegate{
@IBOutlet weak var tableview: UITableView!
var friends : [Friend] = []
var fetchRequestController:NSFetchedResultsController!
@IBOutlet weak var NameTextField: UITextField!
@IBOutlet weak var TelTextField: UITextField!
@IBOutlet weak var PicImageView: UIImageView!
@IBOutlet weak var YesButton: UIButton!
@IBOutlet weak var NoButton: UIButton!
override func viewDidLoad() {

  super.viewDidLoad()
  //讀取Friend的Entity
  var fetchRequest = NSFetchRequest(entityName: "Friend")
  //排序方式用name這個欄位
  let sortDescriptor = NSSortDescriptor(key: "name", ascending: true)
  fetchRequest.sortDescriptors = [sortDescriptor]
  if let managedObjectContext = (UIApplication.sharedApplication().delegate as AppDelegate).managedObjectContext{
      fetchRequestController = NSFetchedResultsController(fetchRequest: fetchRequest, managedObjectContext: managedObjectContext, sectionNameKeyPath: nil, cacheName: nil)
      //delegate設定為自己時,當新增修改刪除SQLite的資料時會呼叫以下事件
      //controllerWillChangeContent()
      //controller(_:didChangeObject:atIndexPath:forChangeType:newIndexPath:)
      //controllerDidChangeContent(_:)
      fetchRequestController.delegate = self
      var e:NSError?
      var result = fetchRequestController.performFetch(&e)
      friends = fetchRequestController.fetchedObjects as [Friend]
      if result != true{
           println(e?.localizedDescription)
      }
  }

}

  override func didReceiveMemoryWarning() {
  super.didReceiveMemoryWarning()
  // Dispose of any resources that can be recreated.

}

  func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
  let identifier = "cell"
  var cell = tableView.dequeueReusableCellWithIdentifier(identifier) as customCell
  cell.nameLabel.text = friends[indexPath.row].name
  cell.telLabel.text = friends[indexPath.row].tel.stringValue
  cell.picImageView.image = UIImage(data: friends[indexPath.row].picture)
  cell.marryLabel.text = friends[indexPath.row].marry.boolValue ? "YES" : "NO"
  return cell

}

  func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
  return friends.count

}
@IBAction func MarryButtonClick(sender: AnyObject) {

  YesButton.backgroundColor = (sender as UIButton == YesButton) ? UIColor.redColor() : UIColor.lightGrayColor()
  NoButton.backgroundColor = (sender as UIButton == NoButton) ? UIColor.redColor() : UIColor.lightGrayColor()

}
@IBAction func SelectPictureClick(sender: AnyObject) {

  let imagePicker = UIImagePickerController()
  imagePicker.allowsEditing = false
  imagePicker.sourceType = UIImagePickerControllerSourceType.PhotoLibrary
  imagePicker.delegate = self
  //顯示挑選圖片的視窗
  self.presentViewController(imagePicker, animated: true, completion: nil)

}
func imagePickerController(picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [NSObject : AnyObject]) {

  PicImageView.image = info[UIImagePickerControllerOriginalImage] as? UIImage
  PicImageView.contentMode = UIViewContentMode.ScaleAspectFill
  PicImageView.clipsToBounds = true
  //關閉挑選圖片的視窗
  dismissViewControllerAnimated(true, completion: nil)

}
@IBAction func SaveClick(sender: AnyObject) {

  if let manageObjectContext = (UIApplication.sharedApplication().delegate as AppDelegate).managedObjectContext{
      var friend = NSEntityDescription.insertNewObjectForEntityForName("Friend", inManagedObjectContext: manageObjectContext) as Friend
      friend.name = NameTextField.text
      friend.tel = TelTextField.text.toInt()
      friend.marry = (YesButton.backgroundColor == UIColor.redColor()) ? true : false
      friend.picture = UIImagePNGRepresentation(PicImageView.image)
      var e:NSError?
      if manageObjectContext.save(&e) != true{
          println("error: \(e?.localizedDescription)")
          return
      }
  }

}
//資料庫準備更新了
func controllerWillChangeContent(controller: NSFetchedResultsController) {

  tableview.beginUpdates()

}
func controller(controller: NSFetchedResultsController, didChangeObject anObject: AnyObject, atIndexPath indexPath: NSIndexPath?, forChangeType type: NSFetchedResultsChangeType, newIndexPath: NSIndexPath?) {

  switch type{
  case .Insert:
      tableview.insertRowsAtIndexPaths([newIndexPath!], withRowAnimation: UITableViewRowAnimation.Fade)
  case .Delete:
      tableview.deleteRowsAtIndexPaths([indexPath!], withRowAnimation: UITableViewRowAnimation.Fade)
  case .Update:
      tableview.reloadRowsAtIndexPaths([indexPath!], withRowAnimation: UITableViewRowAnimation.Fade)
  default:
      tableview.reloadData()
  }
  friends = controller.fetchedObjects as [Friend]

}
func controllerDidChangeContent(controller: NSFetchedResultsController) {

  tableview.endUpdates()

}
}