CODEWITHSUNDEEP
iosswifttableviewindexpath
Ali
Ali

Reputation: 5111

iOS TableView Index Value on Scroll

I am using table view in my Swift project. The problem is with table view cell index path value. When the table gets loaded initially, the index values are ok. But as soon as I scroll my table view the cell index paths change and the ids I get from a data array are wrong. Googling results that it is because of reusable cell like thing. Here's my view controller code:

//
//  ProjectsController.swift
//  PMUtilityTool
//
//  Created by Muhammad Ali on 9/23/16.
//  Copyright © 2016 Genetech Solutions. All rights reserved.
//

import UIKit

class ProjectsController: UIViewController {

    //MARK: Properties
    var ProjectsArray: Array<Project> = []

    @IBOutlet weak var ProjectsTableView: UITableView!

    override func viewDidLoad() {
        super.viewDidLoad()

        // Do any additional setup after loading the view.
        self.navigationController?.navigationBarHidden = true

        // Remove indenting of cell
        if self.ProjectsTableView.respondsToSelector(Selector("setSeparatorInset:")) {
            self.ProjectsTableView.separatorInset = UIEdgeInsetsZero
        }
        if self.ProjectsTableView.respondsToSelector(Selector("setLayoutMargins:")) {
            self.ProjectsTableView.layoutMargins = UIEdgeInsetsZero
        }

        self.ProjectsTableView.layoutIfNeeded()

        // Get projects
        getProjects()
    }

    override func viewWillAppear(animated: Bool) {
        self.navigationController?.navigationBarHidden = true
    }

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

    /*
     // MARK: - Navigation

     // In a storyboard-based application, you will often want to do a little preparation before navigation
     override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
     // Get the new view controller using segue.destinationViewController.
     // Pass the selected object to the new view controller.
     }
     */

    // MARK: - TableView Datasource
    func numberOfSectionsInTableView(tableView: UITableView) -> Int
    {
        return 1
    }

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

    func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
        // print("clicked")
    }

    func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> ProjectTableViewCell {

        print(indexPath.row)

        let cell = tableView.dequeueReusableCellWithIdentifier("ProjectViewCell", forIndexPath:indexPath) as! ProjectTableViewCell

        // Remove indenting of cell
        cell.separatorInset = UIEdgeInsetsZero
        cell.layoutMargins = UIEdgeInsetsZero

        // Set project name
        cell.ProjectName.text = "\((indexPath.row)+1). \(self.ProjectsArray[indexPath.row].ProjectName)"

        // Set action button
        cell.ActionButton.tag = indexPath.row
        cell.ActionButton.addTarget(self, action: #selector(ProjectsController.projectActions(_:)), forControlEvents: .TouchUpInside)

        return cell

    }

    func reloadTableViewAfterDelay()
    {
        ProjectsTableView.performSelector(#selector(UITableView.reloadData), withObject: nil, afterDelay: 0.1)
    }

    @IBAction func projectActions(sender: UIButton) {
        let index = sender.tag

        let optionMenu = UIAlertController(title: nil, message: self.ProjectsArray[index].ProjectName, preferredStyle: .ActionSheet)

        // Report Progress
        let reportProgressAction = UIAlertAction(title: "Report Progress", style: .Default, handler: {
            (alert: UIAlertAction!) -> Void in
            self.performSegueWithIdentifier("ShowReportProgress", sender: sender)
        })

        // Cancel
        let cancelAction = UIAlertAction(title: "Cancel", style: .Cancel, handler: {
            (alert: UIAlertAction!) -> Void in

        })

        optionMenu.addAction(reportProgressAction)
        optionMenu.addAction(cancelAction)

        self.presentViewController(optionMenu, animated: true, completion: nil)
    }

    override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {

        if let button = sender where segue.identifier == "ShowReportProgress" {
            let upcoming: ReportProgressController = segue.destinationViewController as! ReportProgressController
            print(self.ProjectsArray[button.tag].ProjectId)
            upcoming.ProjectId = self.ProjectsArray[button.tag].ProjectId
            upcoming.ProjectName = self.ProjectsArray[button.tag].ProjectName
        }

    }

    // MARK: Get Projects Function
    func getProjects() -> Void
    {

        var params = Dictionary<String,AnyObject>()
        params =  ["user_id":CFunctions.getSession("id")]

        WebServiceController.getAllProjects(params){ (type, response, message) -> Void in

            if (type == ResponseType.kResponseTypeFail)
            {

                // Show Error
                let alert = UIAlertController(title: "Error(s)", message:"Unable to load projects.", preferredStyle: .Alert)
                alert.addAction(UIAlertAction(title: "OK", style: .Default) { _ in })
                self.presentViewController(alert, animated: true){}

            }
            else
            {
                //debugPrint(response)

                if(response.count>0)
                {
                    self.ProjectsArray = response
                }
                else
                {
                    // Show Error
                    let alert = UIAlertController(title: "Error(s)", message:"No projects found.", preferredStyle: .Alert)
                    alert.addAction(UIAlertAction(title: "OK", style: .Default) { _ in })
                    self.presentViewController(alert, animated: true){}
                }

                self.reloadTableViewAfterDelay()

            }
        }
    }

}

I want each cell's index value to be intact whether I scroll down or up.

Upvotes: 1

Views: 2500

Answers (4)

Shivbaba&#39;s son
Shivbaba&#39;s son

Reputation: 1369

In your iPhone screen, for example you can see 5 cells at a time.

  1. So, first time, when you load tableView cellForRowAtindexPAth method will be called for first 5 cells.

    "As you mentioned, first time you are loading and tableView indexes are correct."

  2. Now when you scroll down, cellForRowAtIndexPath method will be called for only 6 and 7.

    "Till this time everything works ok, as you mentioned. AS you can see overall indexpath as intact 1,2, 3,4,5,6,7."

    *Dark cells are currently visible on your screen.

  3. Now when you scroll up {2 cells}. Now you can see the current visible cell's on your screen are 1,2,3,4,5.

Here, cellForRowAtIndexPath method will be called for ONLY cells numbered 2,1.

Because cell numbers 3,4,5 are already loaded/visible in your screen.

So, your Print log will be 1,2,3,4,5,6,7,2,1.

Upvotes: 1

Chandresh Kachariya
Chandresh Kachariya

Reputation: 677

Need to get indexPath of button using tableViewCell's than used below code

func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
     return 10
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
    let cellId: NSString = "Cell"
    let cell: UITableViewCell = tableView.dequeueReusableCellWithIdentifier(cellId as String)! as UITableViewCell

    let ActionButton : UIButton = cell.viewWithTag(10) as! UIButton

    ActionButton.addTarget(self, action: #selector(ViewController.projectActions(_:)), forControlEvents: UIControlEvents.TouchUpInside)

    return cell
}

@IBAction func projectActions(sender: UIButton) {
    let buttonPosition = sender.convertPoint(CGPointZero, toView: self.tableView)
    let indexPath = self.tableView.indexPathForRowAtPoint(buttonPosition)
    print(indexPath?.row)

}

Upvotes: 0

KKRocks
KKRocks

Reputation: 8322

You need to get indexPath of button using tableViewCell's hierarchy.

 @IBAction func projectActions(sender: UIButton) {
  let button = sender as! UIButton
  let view = button.superview!
  let cell = view.superview as! UITableViewCell
  let indexPath = self.reloadTableViewAfterDelay.indexPathForCell(cell)
  let index = indexPath.row
}

 if let button = sender where segue.identifier == "ShowReportProgress" {
       let upcoming: ReportProgressController =  segue.destinationViewController as! ReportProgressController
       let view = button.superview!
       let cell = view.superview as! UITableViewCell
       let indexPath = self.reloadTableViewAfterDelay.indexPathForCell(cell)
       let index = indexPath.row
       print(self.ProjectsArray[index].ProjectId)
       upcoming.ProjectId = self.ProjectsArray[index].ProjectId
       upcoming.ProjectName = self.ProjectsArray[index].ProjectName
       }

Upvotes: 0

MRustamzade
MRustamzade

Reputation: 1455

You should add UITableViewDelegate and UITableViewDataSource to your class. and set it ProjectsTableView.delegate = self in viewDidLoad.

Upvotes: 0

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