我使用Swift和Parse创建了一个todo应用程序。我试图给出一个重置按钮功能，但我不知道从哪里开始。我的代码如下。
在代码中途，我有一个IBAction。
// Reset all tasks to uncompleted state
@IBAction func resetTasks(sender: UIBarButtonItem) {
}
我不想重置整个应用中的每个任务。我想重置该特定部分中的任务（在应用程序中称为“团队”）。我是否使用for循环来遍历任务数组？如果是这样，我如何使用PFObjects做到这一点？
import UIKit
import Parse
protocol TaskCellDelegate {
func doneHit(cell : TaskCell)
}
class TaskCell : UITableViewCell {
var delegate : TaskCellDelegate?
@IBOutlet weak var label: UILabel!
@IBOutlet weak var checkBox: CheckBox!
@IBOutlet weak var detailLabel: UILabel!
override func awakeFromNib() {
super.awakeFromNib()
checkBox.addTarget(self, action: "buttonClicked:", forControlEvents: UIControlEvents.TouchUpInside)
}
func buttonClicked(sender:UIButton) {
delegate?.doneHit(self)
}
}
class CheckBox: UIButton {
//images
let checkedImage = UIImage(named: "checkedbox")
let unCheckedImage = UIImage(named: "uncheckedbox")
//bool propety
var isChecked:Bool = false{
didSet {
if isChecked == true{
self.setImage(checkedImage, forState: .Normal)
}
else {
self.setImage(unCheckedImage, forState: .Normal)
}
}
}
override func awakeFromNib() {
self.addTarget(self, action: "buttonClicked:", forControlEvents: UIControlEvents.TouchUpInside)
}
func buttonClicked(sender:UIButton) {
if(sender == self){
if isChecked == false {
isChecked = true
} else {
isChecked = false
}
}
}
}
class AdminTasksTVC: UITableViewController, TaskCellDelegate {
override func viewWillAppear(animated: Bool) {
if (PFUser.currentUser() == nil) {
dispatch_async(dispatch_get_main_queue(), { () -> Void in
let viewController:UIViewController = self.storyboard!.instantiateViewControllerWithIdentifier("Login")
self.presentViewController(viewController, animated: true, completion: nil)
})
}
}
var checked = CheckBox()
var user = ""
var team = ""
var tasks = [PFObject]() {
didSet {
tableView?.reloadData()
}
}
@IBAction func addBarButtonTapped(sender: UIBarButtonItem) {
let ac = UIAlertController(title: "Add Task", message: nil, preferredStyle: .Alert)
ac.addTextFieldWithConfigurationHandler() {textField in
textField.placeholder = "Task"
}
ac.addAction(UIAlertAction(title: "Cancel", style: .Cancel, handler: nil))
ac.addAction(UIAlertAction(title: "Post", style: .Default, handler: {action in
if let task = ac.textFields?[0].text {
if task.characters.count == 0 {
UIAlertView(title: "Add a task", message: nil, delegate: nil, cancelButtonTitle: "OK").show()
return
}
let obj = PFObject(className: "Tasks")
obj.setValue(task, forKey: "task")
obj.setValue(self.team, forKey: "team")
obj.setValue(self.checked.isChecked, forKey: "done")
obj.setValue(self.user, forKey: "completedBy")
obj.saveInBackgroundWithBlock() {success,error in
if error != nil {
print(error)
return
}
if success {
self.loadTasks()
}
}
}
}))
presentViewController(ac, animated: true, completion: nil)
}
func loadTasks() {
let query = PFQuery(className: "Tasks")
query.whereKey("team", equalTo: team)
query.findObjectsInBackgroundWithBlock { (objects, error : NSError?) -> Void in
if let objects = objects {
self.tasks = objects
}
}
self.refreshControl?.endRefreshing()
}
// Reset all tasks to uncompleted state
@IBAction func resetTasks(sender: UIBarButtonItem) {
}
func loginType() {
if let user = PFUser.currentUser() {
print("\(user)")
let type = user.objectForKey("type") as! String
print("\(type)")
if type == "admin" {
self.navigationItem.rightBarButtonItem = self.editButtonItem()
}
} }
override func viewDidLoad() {
super.viewDidLoad()
// Uncomment the following line to preserve selection between presentations
// self.clearsSelectionOnViewWillAppear = false
// Uncomment the following line to display an Edit button in the navigation bar for this view controller.
loginType()
let refreshControl = UIRefreshControl()
refreshControl.attributedTitle = NSAttributedString(string: "Pull to Refresh")
refreshControl.addTarget(self, action: Selector("loadTasks"), forControlEvents: UIControlEvents.ValueChanged)
self.refreshControl = refreshControl
tableView?.rowHeight = UITableViewAutomaticDimension
tableView?.estimatedRowHeight = 44
loadTasks()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
// MARK: - TaskCellDelegate
func doneHit(cell:TaskCell) {
if let ip = tableView.indexPathForCell(cell) {
let task = tasks[ip.row]
let query = PFQuery(className: "Tasks")
query.getObjectInBackgroundWithId(task.objectId!) { (object, error) -> Void in
if error != nil {
print(error)
}
else if let object = object {
object["done"] = cell.checkBox.isChecked
print(cell.checkBox.isChecked)
if cell.checkBox.isChecked == true {
object["completedBy"] = "Completed by: \(PFUser.currentUser()!.email!)"
}
else {
object["completedBy"] = ""
}
object.saveInBackground()
self.tasks[ip.row] = object
}
}
}
}
/*
task.setValue(cell.checkBox.isChecked, forKey:"done")
task.saveInBackgroundWithBlock() {success,error in
if error != nil {
print(error)
return
}
if success {
//self.tableView.reloadData()
}
}
*/
// MARK: - Table view data source
override func numberOfSectionsInTableView(tableView: UITableView) -> Int {
// #warning Incomplete implementation, return the number of sections
return 1
}
override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
// #warning Incomplete implementation, return the number of rows
return tasks.count
}
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("TaskCell", forIndexPath: indexPath) as! TaskCell
// Configure the cell...
cell.selectionStyle = .None
let idx = tasks[indexPath.row]
let task = idx["task"] as! String
if let label = cell.viewWithTag(1) as? UILabel {
label.text = task
}
let done = idx["done"] as! Bool
if let checkBox = cell.viewWithTag(2) as? CheckBox {
checkBox.isChecked = done
}
let completedBy = idx["completedBy"] as? String
if let userCompleted = cell.viewWithTag(3) as? UILabel {
userCompleted.text = completedBy
}
cell.delegate = self
return cell
}
/*
// Override to support conditional editing of the table view.
override func tableView(tableView: UITableView, canEditRowAtIndexPath indexPath: NSIndexPath) -> Bool {
// Return false if you do not want the specified item to be editable.
return true
}
*/
// Override to support editing the table view.
override func tableView(tableView: UITableView, commitEditingStyle editingStyle: UITableViewCellEditingStyle, forRowAtIndexPath indexPath: NSIndexPath) {
if editingStyle == .Delete {
if let user = PFUser.currentUser() {
print("\(user)")
let type = user.objectForKey("type") as! String
print("\(type)")
if type == "admin" {
// Delete the row from the data source
tasks[indexPath.row].deleteInBackgroundWithBlock({ (success, error) -> Void in
if error != nil {
print(error)
return
}
if success {
tableView.beginUpdates()
self.tasks.removeAtIndex(indexPath.row)
tableView.deleteRowsAtIndexPaths([indexPath], withRowAnimation: .Fade)
tableView.endUpdates()
}
})
self.loadTasks()
}
}
} else if editingStyle == .Insert {
// Create a new instance of the appropriate class, insert it into the array, and add a new row to the table view
}
}
任何和所有帮助都非常有用。谢谢！
答案 0 :(得分：1)
任务是一个PFObject数组，所以你对for循环的想法可以正常工作，一旦它按照你的意愿填充，就可以遍历该集合......
// Reset all tasks to uncompleted state
@IBAction func resetTasks(sender: UIBarButtonItem) {
for task in tasks {
//do whatever you'd like here to each piece (task) of tasks
task.doWhateverToEachTask
}
}