the main role is to display the playlists names in table view, but it show me word "name" in about 500 cells!
I can make a simple errors, because i only learning swift, and it is my first programming language
There is the code:
import UIKit
import MediaPlayer
class ViewController: UIViewController, UITableViewDelegate, UITableViewDataSource {
#IBOutlet var tableView: UITableView!
var tableData = MPMediaQuery.playlistsQuery()
var songname: NSString = MPMediaPlaylistPropertyName
override func viewDidLoad() {
super.viewDidLoad()
self.tableView.registerClass(UITableViewCell.self, forCellReuseIdentifier: "cell")
self.tableView.reloadData()
}
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return self.tableData.items.count
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
var cell: UITableViewCell = self.tableView.dequeueReusableCellWithIdentifier("cell") as UITableViewCell
cell.textLabel.text = songname
return cell
}
func tableView(tableView: UITableView!, didSelectRowAtIndexPath indexPath: NSIndexPath!) {
println("Row \(indexPath.row) selected")
}
}
Your problem is that you're displaying MPMediaPlaylistPropertyName in the cell which is most likely just the constant string "name"
What you need to do is set the cell's textLabel with the actual name of the playlist which would look something like this in your cellForRowAtIndexPath method
Replace
cell.textLabel.text = songname
With
let playlist: MPMediaPlaylist = tableData.collections[indexPath.row] as MPMediaPlaylist
let playlistName = playlist.valueForProperty(MPMediaPlaylistPropertyName) as NSString
cell.textLabel.text = playlistName;
Also, you need to make sure you're getting the count from the collections of the tableData so in your number of rowsInSectionMethod change:
return self.tableData.items.count
to
return self.tableData.collections.count
For A bit more understanding, what we're doing in the cellForRowAtIndexPath now is:
Getting a specific MPMediaPlaylist item for that particular row
Getting the Name of the playlist and assigning it to a variable
Assigning that name to the cells textLabel
Let me know if you have any other questions
You have to cleanup the cell data since you are re-using the cells,
Right after line
var cell: UITableViewCell = self.tableView.dequeueReusableCellWithIdentifier("cell") as UITableViewCell
do
cell.textLabel.text = ""
Related
I am new to programming and currently working on a newsfeed like app. I had a normal Table view up and running fine, but want to try it now with a costume cell type. So I created one and thought connecting the labels the usual way would be perfectly fine, but I was wrong. So I am wondering how I can let my Text label connect to my view controller, so I can use my custom cell.
class ViewController: BaseViewController, UITableViewDelegate, UITableViewDataSource {
#IBOutlet var newsfeedTableView: UITableView!
var ref: DatabaseReference!
var posts = [String]()
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return (posts.count)
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = UITableViewCell(style: UITableViewCell.CellStyle.default, reuseIdentifier: "cell")
//here is where I need the custom label to get the posts
cell.textLabel?.text = posts[indexPath.row]
cell.textLabel?.font = UIFont.boldSystemFont(ofSize: 18.0)
return cell
}
}
Create subclass of UITableViewCell and connect IBOutlets to this class
class YourCell: UITableViewCell {
#IBOutlet weak var customLabel: UILabel!
...
}
don't forget to set class of your prototype cell in storyboard:
then in cellForRowAt data source method downcast your dequeued cell as YourCell
let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath) as! YourCell
then you have access to YourCell outlets
cell.customLabel.text = "SomeText"
...
I'm assuming that you are using Storyboard.
First of all, you should understand that there is little difference when you use own custom table cell. In that case, in the method "cellForRowAtIndexPath", after dequeue your cell, you just have to typecast table cell like 'as! YourCustomTableCellClass'. After this line, you can access each property of this class.
First, design your table cell on Storyboard whatever you want.
Now, make a subclass of UITableViewCell and assign this class to your prototype custom cell which you have designed on Storyboard. Also, don't forget to set "reuse identifier in Storyboard table cell.
Then connect your outlets with custom cell class from Storyboard.
Now you can use code like this:
class YourTableCellClass: UITableViewCell {
// I'm using these outlets as a sample, but you have to connect them from Storyboard.
var leftTextLabel: UILabel!
var rightTextLabel: UILabel!
}
class YourTableController: UITableViewController {
override func viewDidLoad() {
super.viewDidLoad()
}
// MARK: - TableView Delegate & DataSource
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return 1 // return your number of rows here...
}
override func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
return 100 // return the height for the row here.....or you can set height from Storyboard if you have fix height of all rows.
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "CellIdentifier", for: indexPath) as! YourTableCellClass
cell.leftTextLabel.text = "Text" // Set text here....
cell.rightTextLabel.text = "Text" // Set text here....
return cell
}
}
Currently I have a tableview that loads cells when I scroll down (scrollview). Is it possible to load and populate all cells on viewDidLoad. I would like to assign data to a cell before it can be viewed. I have tried using self.tableView.reloadData() but not successful.
If you don't want to use UITableView's cell reusing concept, then create all the UITableViewCells beforehand in viewDidLoad and store them in an array.
Example:
class ViewController: UIViewController, UITableViewDataSource
{
var arr = [UITableViewCell]()
override func viewDidLoad()
{
super.viewDidLoad()
//Create your custom cells here and add them to array
let cell1 = UITableViewCell()
let cell2 = UITableViewCell()
arr.append(cell1)
arr.append(cell2)
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int
{
return arr.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell
{
return arr[indexPath.row]
}
}
I am using UISegmentControl to display objective type questions in table view. But, if I select one segment in any one of cell, then if I scroll, some segment values are changed. I dont know how to solve that.
Kindly guide me.
Cell size : 160px
Segment tint color : blue color
Coding
//UIViewController
func numberOfSectionsInTableView(tableView: UITableView) -> Int {
return 1
}
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return 10
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = segTblVw.dequeueReusableCellWithIdentifier("segment", forIndexPath: indexPath) as! segmentTblCell
return cell
}
//UITableViewCell CLASS
class segmentTblCell: UITableViewCell {
#IBOutlet weak var segMent: UISegmentedControl!
override func awakeFromNib() {
super.awakeFromNib()
// Initialization code
}
override func setSelected(selected: Bool, animated: Bool) {
super.setSelected(selected, animated: animated)
// Configure the view for the selected state
}
}
Screen shot below:
You're having this problem because of how dequeueReusableCellWithIdentifier: works. Each time a cell get scrolled out of screen, it enters a cache area where it will be reused.
Let's say you have 100 cells. All their segmentedControl objects are set to first. You tap on one to change it's value. As the cell moves out of view, it enters the cache, where it will be dequeued if you scroll down further.
It's important to understand this, because the segmentedControl object is not actually changing. It looks like it's changing because of the dequeue behaviour.
To solve this problem, you will need to implement a dataSource that stores the segmentedControl object's value so you can reinitialize it correctly every time a cell is dequeued.
Method 1: Prevent reusability of cells by, Holding all cell objects in an array
var arraysCells : NSMutableArray = []//globally declare this
in viewDidLoad()
for num in yourQuestionArray//this loop is to create all cells at beginning
{
var nib:Array = NSBundle.mainBundle().loadNibNamed("SegmentTableViewCell", owner: self, options: nil)
var cell = nib[0] as? SegmentTableViewCell
arraysCells.addObject(cell!);
}
in tableViewDelegate,
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
return arraysCells.objectAtIndex(indexPath.row) as! UITableViewCell
}
you can find the selected segment values (answer) by iterating arraysCells
NOTE: Method 1 will be slow, if you have big number of cells
Method 2: Reuse the cell as normal, but save the states(enterd values) Using Delegate and arrays.
in custom UITableViewCell
#objc protocol SegmentTableViewCellDelegate {
func controller(controller: SegmentTableViewCell, selectedSegmentIndex:Int, indexPath : NSIndexPath)
}
class SegmentTableViewCell: UITableViewCell {
var delegate: AnyObject?
var indexPath : NSIndexPath?
#IBOutlet weak var segment: UISegmentedControl! //outlet of segmented Control
#IBAction func onSegmentValueChanged(sender: UISegmentedControl/*if the parameter type is AnyObject changed it as UISegmentedControl*/)//action for Segment
{
self.delegate?.controller(self, selectedSegmentIndex: sender.selectedSegmentIndex, indexPath: indexPath!)
}
in viewController
class MasterViewController: SegmentTableViewCellDelegate{
var selectedAnswerIndex : NSMutableArray = [] //globally declare this
var selectedSegmentsIndexPath : NSMutableArray = [] //globally declare this
func controller(controller: SegmentTableViewCell, selectedSegmentIndex:Int, indexPath : NSIndexPath)
{
if(selectedSegmentsIndexPath.containsObject(indexPath))
{
selectedAnswerIndex.removeObjectAtIndex(selectedSegmentsIndexPath.indexOfObject(indexPath))
selectedSegmentsIndexPath.removeObject(indexPath)
}
selectedAnswerIndex.addObject(selectedSegmentIndex)
selectedSegmentsIndexPath.addObject(indexPath)
}
in cellForRowAtIndexPath (tableView Delegate)
if(selectedSegmentsIndexPath.containsObject(indexPath))
{
cell?.segment.selectedSegmentIndex = selectedAnswerIndex.objectAtIndex(selectedSegmentsIndexPath.indexOfObject(indexPath)) as! Int
}
cell?.delegate = self
cell?.indexPath = indexPath
you can get the result by
for index in selectedSegmentsIndexPath
{
var cellIndexPath = index as! NSIndexPath
var answer : Int = selectedAnswerIndex.objectAtIndex(selectedSegmentsIndexPath.indexOfObject(cellIndexPath)) as! Int
NSLog("You have enterd answer \(answer) for question number \(cellIndexPath.row)")
}
#KelvinLau's is perfect
you can do that by using var segmentedTracker : [NSIndexPath:Int] = [:]
on segmentedValueChanged set the value of the selectedIndex ie: segmentedTracker[indexPath] = valueOf the selected index
then in cellForRowAtIndexPath check for the value let selected = [segmentedTracker]
cell.yourSegmentedControlReference.selectedIndex = selected
please note this is a pseudocode I don't remember the properties name. From here you can figure it out by urself
I think to use UISegmentControl in UITableViewCell may be wrong.
https://developer.apple.com/library/ios/documentation/UIKit/Reference/UISegmentedControl_Class/
I have never seen the kind of that in iOS application.
The problem is that UITableViewCell is reused by dequeueReusableCellWithIdentifier method. So some UISegmentControl values are changed when scrolling.
Although it is not best solution, you can use Static Cells. What you need to do is that only switch Static cells. And If so, you don't write code of UITableViewCell.
Year 2018: Updated Answer
Find my easiest answer in this UISegement inside UITableViewCell
=======================================================
Year 2015
I have tested in my own way. My coding is below. Kindly guide me, whether it is right way or wrong way? My problem get solved. This code stops reusable cell.
My Coding Below:
//UIViewController
var globalCell = segmentTblCell() //CUSTOM UITableViewCell Class
func numberOfSectionsInTableView(tableView: UITableView) -> Int {
return 1
}
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return 10
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = segTblVw.dequeueReusableCellWithIdentifier("segment", forIndexPath: indexPath) as! segmentTblCell
globalCell = segTblVw.dequeueReusableCellWithIdentifier("segment", forIndexPath: indexPath) as! segmentTblCell //THIS LINE - STOPS REUSABLE TABLE.
return cell
}
I understand that I need to implement required methods in the controller and establish a relationship between view and controller.. but where do the identifier "tableView" in
func tableView(mintabell: UITableView, numberOfRowsInSection section: Int) -> Int
{
return items.count
}
come from and what if I want several tableviews on same view? How to declare them separately?
These are the protocols that you need to declare for a TableView
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
return createCellAndReturnItHere
}
func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
}
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return numberOfCellsInSection
}
In terms of having more than one tableview in one ViewController.. If you have an outlet for each tableview then you can check which one you need inside the protocol functions:
#IBOutlet weak var tableViewOne: UITableView!
#IBOutlet weak var tableViewTwo: UITableView!
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
if tableView == self.tableViewOne {
return createCellForTableViewOneAndReturnItHere
} else {
return createCellForTableViewOneAndReturnItHere
}
}
Think of it like a box. Every tableView that is subscribed to the protocol grabs in that box leaves its fingerprint and takes what it gets. So if you have multiple tableViews in one controller you can distinguish them by checking for equality.
Example:
class MyViewController: UIViewController, UITableViewDataSource, UITableViewDelegate {
let firstTableView = UITableView()
let secondTableView = UITableView()
viewDidLoad() {
firstTableView.delegate = self
secondTableView.delegate = self
firstTableView.dataSource = self
secondTableView.dataSource = self
}
// ... some othe methods...
func tableView(mintabell: UITableView, numberOfRowsInSection section: Int) -> Int
{
if tableView == firstTableView {
return 10
}
if tableView == secondTableView {
return 20
}
return 0
}
}
Delegates are implemented by the developer and called by iOS not the developer. The tableView is passed by iOS and points to the particular tableview.
If you have several tableviews with the same delegate you can compare the passed tableview parameter to the tableviews you have implemented to determine which one.
Alternatively, create a tableView delegate and datasource per tableView. This will eliminate testing which tableView removing a lot of conditional logic from the code.
First of all, you don't necessarily always have to implement a protocol for every view. Only when you have a view which has delegate that needs implementing, you will have to conform that protocol responsible for that delegate implementation.
So for tableView, first you drag a UITableView in your Controller from the Object Library and then a UITableViewCell under the Table View.
Now go to the ViewController.swift file and add
#IBOutlet var myFirstTableView: UITableView!
right after the line.
class ViewController: UIViewController
P.S: If you have more than one table then you could just declare the extra table's here., like-
#IBOutlet var mySecondTableView: UITableView!
Now, let's assume, you have one table. Now, you need to add the list of protocols. So, just add UITableViewDelegate, UITableViewDataSource with
class ViewController: UIViewController
appended by comma.
Adding this should give you an error but that's okay. This is because you have not added the required method listed under that UITableViewDatasource protocol.
So, just add those required methods and implement it accordingly.
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return 3;
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
var cell:UITableViewCell = self.tableView.dequeueReusableCellWithIdentifier("myCell") as! UITableViewCell
cell.textLabel?.text = "test"
return cell
}
Here, I said, I will have 3 cells whose identifier is "myCell" and the cell's textLabel will have a text, "test".
Now, we forgot a very important step and that is to assign the cell identifier to our TableView Cell. So, go to the storyboard and select the TableView Cell and insert "myCell" as an identifier for your cell.
If you had more than one table, then you would check for which TableView, you are loading your data. So, you could assign a unique tag to each table explicitly(you can do that either from storyboard or from code), and based on that tag, you would implement your methods. Let's say you have 3 tables and the assigned tag is 1,2 and 3. So, you could do something like,
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
if tableView.tag == 1{
return 3
}
else if tableView.tag == 2{
return 4
}
else{
return 1
}
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
var cell:UITableViewCell = self.tableView.dequeueReusableCellWithIdentifier("cell") as! UITableViewCell
if tableView.tag == 1{
cell.textLabel?.text = "test1"
}
else if tableView.tag == 2{
cell.textLabel?.text = "test2"
}
else{
cell.textLabel?.text = "test"
}
return cell
}
I am using SWRevealViewController, I have three cells like "first" "second" "last". And I have three different tableviews, "firstTableViewController", "secondTableViewController", "lastTableViewController".
I tried to use didSelectRowAtIndexPath, the prepareforsegue. But I couldn't implement multipe segues in didSelectRowAtIndexPath.
Is there a way to do this?
import UIKit
class SideBarTableViewController: UITableViewController {
var MenuArray = [String]()
override func viewDidLoad() {
super.viewDidLoad()
MenuArray = ["First","Second","Last"]
var view = UIView(frame: CGRectZero)
self.tableView.tableFooterView = view
self.tableView.backgroundColor = UIColor.whiteColor()
}
override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return MenuArray.count
}
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
var cell = tableView.dequeueReusableCellWithIdentifier(MenuArray[indexPath.row], forIndexPath: indexPath) as UITableViewCell
cell.textLabel?.text = MenuArray[indexPath.row]
return cell
}
}
cell identifiers : First, Second, Last
Thanks,
Ok, I found the solution. Followed this tutorial, there is no need to set a segue in code, just kntrl+drag to the view controllers and select "SWRevealViewControllerSeguePushController" ...
http://www.appcoda.com/sidebar-menu-swift/