UISwitch not shown in UITable - ios

Question

I have made a UITable with some data and I had include a UISwitch in, but it not shown in the table when its run.
in .h
#interface CalcViewController : UITableViewController {
IBOutlet UITableView *mainTableView;
NSMutableArray *courseMURArray;
NSMutableArray *switchStates;
}
and in .m
- (void)viewDidLoad
{
[super viewDidLoad];
switchStates = [[NSMutableArray alloc] init ];
int i = 0;
for (i = 0; i < 33; i++) {
[switchStates addObject:#"OFF"];
}
}
and in
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:#"Cell"];
UISwitch *theSwitch = nil;
if (cell == nil) {
cell = [[UITableViewCell alloc]initWithStyle:UITableViewCellStyleDefault reuseIdentifier:#"Cell"];
theSwitch = [[UISwitch alloc]initWithFrame:CGRectZero];
theSwitch.tag = 100;
CGRect frame = theSwitch.frame;
frame.origin.x = 230;
frame.origin.y = 8;
theSwitch.frame = frame;
[theSwitch addTarget:self action:#selector(switchChanged:) forControlEvents:UIControlEventValueChanged];
[cell.contentView addSubview:theSwitch];
}else{
theSwitch = [cell.contentView viewWithTag:100];
}
if ([[switchStates objectAtIndex:indexPath.row] isEqualToString:#"ON"]) {
theSwitch.on = YES;
}else{
theSwitch.on = NO;
}
return cell;
}
and this is selector method
-(void) switchChanged: (UISwitch *) sender{
UITableViewCell *theParentCell = [[ sender superview] superview];
NSIndexPath * indexPathOfSwitch = [mainTableView indexPathForCell:theParentCell];
if (sender.on) {
[switchStates replaceObjectAtIndex:indexPathOfSwitch.row withObject:#"ON"];
}else{
[switchStates replaceObjectAtIndex:indexPathOfSwitch.row withObject:#"OFF"];
}
}
every thing is ok with the data but its not with are there any problem?

Answer 1

When you set up the cell in cell for RowAtIndexPath, you're setting the frame to CGRectZero, a rect at position (0,0) with width = height = 0. You then reset the position, but you never reset the the width & height.
After your 2 frame.origin lines add:
frame.size.width = XX;
frame.size.height = YY;
or just use CGRectMake(X, Y, width, height) to make the frame.

Answer 2

In your cellForRowAtIndexPath, if the cell is nil, then you initialise the UISwitch and add it to the cell. What if the cell is not nil initially?
Let's say, UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:#"Cell"] returns a valid cell, then no switch will be created at all.
You may want to verify whether you have specified "Cell" as the identifier for the UITableViewCell in interface builder just in case.
Alternatively, move the code for initialising the UISwitch outside of the "if(cell==nil)". See if this solves your issue. The "if(cell==nil)" block is supposedly for initialising cell if dedequeueReusableCellWithIdentifier: returns nil.
Also, you are using a tag number of 100 for all switches and in the else block, you initialise theSwitch with contentView of tag 100. Which UISwitch should iOS assign to theSwitch if you have more than one switch? You might want to refer to my post on how to set tag numbers correctly.