Expanding and collapsing UITableViewCells with DatePicker

I assume you’re using storyboard, the example is with UIPickerView:
Create a tableviewcell right under the cell that contains the textfield you want to fill and set the cells row height to 216.0 in the inspector and add a UIPickerView to that cell.

Next connect the UIPickerView via Outlet to your viewcontroller and add the following property to your ViewController.h:

@property (weak, nonatomic) IBOutlet UIPickerView *statusPicker;
@property BOOL statusPickerVisible;

In your ViewController.m do in viewWillAppear

self.statusPickerVisible = NO;
self.statusPicker.hidden = YES;
self.statusPicker.translatesAutoresizingMaskIntoConstraints = NO;

Add two methods:

- (void)showStatusPickerCell {
    self.statusPickerVisible = YES;
    [self.tableView beginUpdates];
    [self.tableView endUpdates];
    self.statusPicker.alpha = 0.0f;
    [UIView animateWithDuration:0.25 
                 animations:^{
                     self.statusPicker.alpha = 1.0f;
                 } completion:^(BOOL finished){
                     self.statusPicker.hidden = NO;
                 }];];
}

- (void)hideStatusPickerCell {    
    self.statusPickerVisible = NO;
    [self.tableView beginUpdates];
    [self.tableView endUpdates];
    [UIView animateWithDuration:0.25
                 animations:^{
                     self.statusPicker.alpha = 0.0f;
                 }
                 completion:^(BOOL finished){
                     self.statusPicker.hidden = YES;
                 }];
}

In heightForRowAtIndexPath

-(CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {
    CGFloat height = self.tableView.rowHeight;
    if (indexPath.row == 1){
        height = self.statusPickerVisible ? 216.0f : 0.0f;
    }
    return height;
}

In didSelectRowAtIndexPath

-(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
    if (indexPath.row == 0) {
        if (self.statusPickerVisible){
            [self hideStatusPickerCell];
        } else {
            [self showStatusPickerCell];
        }
    }
    [self.tableView deselectRowAtIndexPath:indexPath animated:YES];
}