Get segmentedcontrol value from tableviewcells - ios

Question

How do i get the value (the selected state) from my segmentedcontrols in the tableviewcells?
When i press the button "Get states" it should return the value for each of the segmented controls. I have tried different methods, but I can't find one that works :(
My code so far:
- (void)viewDidLoad
{
[super viewDidLoad];
tableData = [[NSMutableArray alloc] initWithCapacity:0];
tableData = [NSArray arrayWithObjects:#"First", #"Second", #"Third", nil];
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
// Return the number of rows in the section.
return [tableData count];
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
UITableViewCell *cell = nil;
cell = [tableView dequeueReusableCellWithIdentifier:#"StateCell"];
if (cell == nil)
{
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:#"StateCell"];
}
//Config cell..
cell.textLabel.text = [tableData objectAtIndex:indexPath.row];
NSArray *itemArray = [NSArray arrayWithObjects: #"1", #"2", #"3", nil];
UISegmentedControl *segmentedControl = [[UISegmentedControl alloc] initWithItems:itemArray];
segmentedControl.frame = CGRectMake(110, 7, 100, 28);
[cell.contentView addSubview:segmentedControl];
return cell;
[[self tableView] reloadData];
}
- (IBAction)getStates:(id)sender {
// Ruturn the current selected statement, for the individual cell's segmentedcontrol..
// Ex. First = SelectedState 1, Second = SelectedState 0 & Third = SelectedState 2..
}
So what I'm really is asking for; is what the "Get states" button action has to do..
Thanks for your time!

Answer 1

Your code has a couple of problems. Most of them happen because a UITableView reuses its cells.
You are creating a new UISegmentedControl each time a cell is displayed, which you should not. You should create the UISegmentedControl only if you create the cell, move that code into the cell == nil).
You don't have a dataSource that saves the state of the segments. You should not save states in views, especially not if you are dealing with a tableView, because cells are reused.
Here's an example that will get the functionality you need.
// this is an object of your model, it has a title and saves the selected index
#interface MBFancyObject : NSObject
#property (strong, nonatomic) NSString *title;
#property (assign, nonatomic) NSInteger selectedIndex;
#end
#implementation MBFancyObject
#end
#interface MasterViewController () {
NSMutableArray *_objects; // stores instances of MBFancyObject
}
#end
#implementation MasterViewController
- (void)viewDidLoad {
[super viewDidLoad];
// set up the model
_objects = [NSMutableArray array];
for (NSInteger i = 0; i < 6; i++) {
MBFancyObject *object = [[MBFancyObject alloc] init];
object.title = [NSString stringWithFormat:#"Object #%ld", (long)i];
object.selectedIndex = i % 3;
[_objects addObject:object];
}
UIBarButtonItem *button = [[UIBarButtonItem alloc] initWithTitle:#"Get States" style:UIBarButtonItemStyleBordered target:self action:#selector(logStates:)];
self.navigationItem.rightBarButtonItem = button;
}
#pragma mark - Table View
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
return _objects.count;
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:#"FancyCell"];
if (!cell) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:#"FancyCell"];
// add the segmentedControl when you create a new cell
UISegmentedControl *segmentedControl = [[UISegmentedControl alloc] initWithItems:#[#"1", #"2", #"3"]];
segmentedControl.frame = CGRectMake(110, 7, 100, 28);
[cell.contentView addSubview:segmentedControl];
// add an action so we can change our model if the view changes
[segmentedControl addTarget:self action:#selector(didChangeSegmentedControl:) forControlEvents:UIControlEventValueChanged];
// use a tag so we can retrieve the segmentedControl later
segmentedControl.tag = 42;
}
// either if the cell could be dequeued or you created a new cell,
// segmentedControl will contain a valid instance
UISegmentedControl *segmentedControl = (UISegmentedControl *)[cell.contentView viewWithTag:42];
MBFancyObject *object = _objects[indexPath.row];
cell.textLabel.text = object.title;
segmentedControl.selectedSegmentIndex = object.selectedIndex;
return cell;
}
- (IBAction)didChangeSegmentedControl:(UISegmentedControl *)sender {
// transform the origin of the cell to the frame of the tableView
CGPoint senderOriginInTableView = [self.tableView convertPoint:CGPointZero fromView:sender];
NSIndexPath *indexPath = [self.tableView indexPathForRowAtPoint:senderOriginInTableView];
NSAssert(indexPath, #"must have a valid indexPath");
MBFancyObject *object = _objects[indexPath.row];
object.selectedIndex = sender.selectedSegmentIndex;
}
- (IBAction)logStates:(id)sender {
// query the model, not the view
for (NSInteger i = 0; i < [_objects count]; i++) {
MBFancyObject *object = _objects[i];
NSLog(#"Object \"%#\" - %ld", object.title, (long)object.selectedIndex);
// since you have only one section, each indexPath is 0,i
NSIndexPath *indexPath = [NSIndexPath indexPathForRow:i inSection:0];
}
}
#end

Answer 2

Use an array to store all the segment control values, and when click one segment control then just change the value correspondingly.

Answer 3

You have serious problem with reusing here
Do not ever allocate a new UI element in tableView:cellForRowAtIndexPath: method unless it is in the if condition if (cell == nil)
Change What in Your tableView:cellForRowAtIndexPath: to be
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:#"StateCell"];
if (cell == nil)
{
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:#"StateCell"];
// Add the Segmented Control
NSArray *itemArray = [NSArray arrayWithObjects: #"1", #"2", #"3", nil];
UISegmentedControl *segmentedControl = [[UISegmentedControl alloc] initWithItems:itemArray];
segmentedControl.frame = CGRectMake(110, 7, 100, 28);
segmentedControl.tag = 1;
[cell addSubview:segmentedControl];
}
//Config cell..
cell.textLabel.text = [tableData objectAtIndex:indexPath.row];
// Get that Segmented Control
UISegmentedControl *segmentedControl = (UISegmentedControl *)[cell viewWithTag:1];
segmentedControl.selectedSegmentIndex = 0; // Set your default value here or add your data in an array and read from that array
return cell;
Then in the action of the button do that
for (UITableViewCell *cell in [tableView visibleCells]) {
UISegmentedControl *segmentedControl = (UISegmentedControl *)[cell viewWithTag:1];
NSLog(#"%d",segmentedControl.selectedSegmentIndex);
}
However this code is not perfect unless you have only 3 cells in your table to avoid reuse or visibility problem