UIDatePicker error on dateSheet showInView - ios

Question

I need to show a datePicker when a textField is clicked.
Here is the code:
- (BOOL)textFieldShouldBeginEditing:(UITextField *)textField {
[self setDate];
return NO;
}
-(void)setDate{
dateSheet = [[UIActionSheet alloc] initWithTitle:Nil delegate:nil cancelButtonTitle:nil destructiveButtonTitle:nil otherButtonTitles: nil];
[dateSheet setActionSheetStyle:UIActionSheetStyleBlackTranslucent];
CGRect pickerFrame = CGRectMake(0, 44, 0, 0);
UIDatePicker *datePicker = [[UIDatePicker alloc] initWithFrame:pickerFrame];
[datePicker setDatePickerMode:UIDatePickerModeDateAndTime];
NSDate * maxDate = [NSDate dateWithTimeIntervalSinceNow:(3600 * 24 * 14)];
datePicker.maximumDate = maxDate;
datePicker.minimumDate = [NSDate date];
[dateSheet addSubview:datePicker];
UIToolbar * controlToolBar = [[UIToolbar alloc] initWithFrame:CGRectMake(0, 0, dateSheet.bounds.size.width, 44)];
[controlToolBar setBarStyle:UIBarStyleBlack];
[controlToolBar sizeToFit];
UIBarButtonItem *spacer = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemFlexibleSpace target:nil action:nil];
UIBarButtonItem *setButton = [[UIBarButtonItem alloc] initWithTitle:#"Imposta" style:UIBarButtonItemStyleDone target:self action:#selector(dismissDate)];
setButton.tintColor = [UIColor whiteColor];
UIBarButtonItem *cancelButton = [[UIBarButtonItem alloc] initWithTitle:#"Annulla" style:UIBarButtonItemStyleDone target:self action:#selector(cancelDate)];
cancelButton.tintColor = [UIColor whiteColor];
[controlToolBar setItems:[NSArray arrayWithObjects:spacer, cancelButton, setButton, nil] animated:NO];
[dateSheet addSubview:controlToolBar];
[dateSheet showInView:self.view];
[dateSheet setBounds:CGRectMake(0, 0, 320, 485)];
}
When showInView is called, a lot of errors are shown in console:
CGContextSetFillColorWithColor: invalid context 0x0. This is a serious error. This application, or a library it uses, is using an invalid context and is thereby contributing to an overall degradation of system stability and reliability. This notice is a courtesy: please fix this problem. It will become a fatal error in an upcoming update.
Then the same message with:
CGContextSetStrokeColorWithColor
CGContextSaveGState
CGContextSetFlatness
CGContextAddPath
CGContextDrawPath
CGContextRestoreGState
Why this happens?

Answer 1

After running your code, I found the problem is caused by the nil title of UIActionSheet.
A workaround is modified as below.
dateSheet = [[UIActionSheet alloc] initWithTitle:#"" delegate:nil cancelButtonTitle:nil destructiveButtonTitle:nil otherButtonTitles: nil];
Another good resource for your reference.