UIPickerView added to uitableviewcontroller.view won't rotate - iphone

Question

I have a UIPickerView as subview in a UITableViewController, which I want to slide up in place when a certain row is clicked. I have implemented the necessary dataSource and delegate methods, but the pickerview acts weirdly. It acts as if it were mechanically jammed, it cannot rotate properly, it just moves a little. If I try to spin it a few times I get this message in the debugger console:
SendDelegateMessage: delegate failed
to return after waiting 10 seconds.
main run loop mode:
UITrackingRunLoopMode If you were not
using the touch screen for this entire
interval (which can prolong this
wait), please file a bug.
I googled for this, to no avail.
Anyway, here is the relevant code. As you may guess, this is a number picker (to choose a percentage value).
- (void)viewDidLoad {
[super viewDidLoad];
percentPicker = [[UIPickerViewalloc] initWithFrame:CGRectMake(0,420, 320, 200)];
percentPicker.delegate = self;
percentPicker.dataSource = self;
percentPicker.showsSelectionIndicator = YES;
[self.view addSubview:percentPicker];
}
- (void)viewWillAppear:(BOOL)animated {
// sets the rows to the appropriate value
// etc
}
- (void)startEditingPercentage {
[UIView beginAnimations :nilcontext:NULL];
[UIView setAnimationBeginsFromCurrentState:YES];
[UIViewsetAnimationDuration:kPickerAnimationDuration ];
percentPicker.transform = CGAffineTransformTranslate(CGAffineTransformIdentity, 0, -220.0);
[UIViewcommitAnimations];
}
- (void)stopEditingPercentage {
NSLog(#"stopEditingPercentage");
[UIView beginAnimations :nilcontext:NULL];
[UIViewsetAnimationBeginsFromCurrentState:YES];
[UIViewsetAnimationDuration:kPickerAnimationDuration];
percentPicker.transform = CGAffineTransformIdentity;
[UIView commitAnimations];
}
#pragma mark UIPickerView delegate and dataSource methods
- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView {
return4;
}
- (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component {
return10;
}
- (CGFloat)pickerView:(UIPickerView *)pickerView widthForComponent:(NSInteger)component {
return44;
}
- (UIView *)pickerView:(UIPickerView *)pickerView viewForRow:(NSInteger)row forComponent:(NSInteger)component reusingView:(UIView *)view {
UILabel *retval = (UILabel *)view;
if (!retval) {
retval= [[UILabel newLabelWithPrimaryColor :[UIColorblackColor ] selectedColor:[ UIColor blackColor] fontSize:22bold:YEStransparent:YES] autorelease];
}
retval.frame = CGRectMake(0, 0, 44, 44);
retval.textAlignment = UITextAlignmentCenter;
retval.backgroundColor = [UIColor clearColor];
retval.text = [NSStringstringWithFormat:#"%i", row];
if (component > 1 ) {
// rows 2 and 3 are decimal, white on black
retval.backgroundColor = [UIColor blackColor];
retval.textColor = [UIColor whiteColor];
}
return retval;
}
- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component {
NSString *selectedValue;
selectedValue= [NSString stringWithFormat:#"%i%i.%i%i" ,[percentPickerselectedRowInComponent :0], [ percentPickerselectedRowInComponent: 1], [percentPickerselectedRowInComponent:2], [percentPickerselectedRowInComponent:3]];
NSNumberFormatter *formatter = [[NSNumberFormatter alloc] init];
NSString *trimmedValue = [[formatter numberFromString:selectedValue] stringValue];
percentValue.text = trimmedValue;
[formatter release];
}
As you see, I use the transform property to move the picker in and out (down) my main view; the startEditing and stopEditing methods are triggered by selection in the teble view. Yet, for the debugging purposes, I eliminated these transitions , and left the picker on top of the table, but nothing changed. I also commented the didSelect method, but this also didn't change anything.
By the way, the same picker-view construction code vorkw allright in another view of the same app.
Any suggestion?
Cheers,

Answer 1

You aren't really adding the picker to UITableView using the code in viewDidLoad. UITableView can only have controls/rows in UITableViewCells and these are specified in the cellForRowAtIndex method. We cannot add controls to UITableView like we do to UIView.
Try using a subclass of UIView instead and add the UITableView and the picker to this UIView subclass.
In case you want to use a UITableViewController subclass only, create a custom cell and add the picker to this custom cell. But then you won't be able to hide/unhide this cell if you add it statically. Then you'll have to use reloadData. I would suggest using the UIView subclass.