Lec 12 Pickers CS 3800 Introduction to IOS programming Lecture 12 Summer 2011

Announcments Program 5 due Wednesday Midterm Exam Thursday Project Proposals due… Ch8 TableViews deferred …. Lec 12 Pickers

Topics Pickers UIDatePicker –NSDate class Custom Pickers –Data source –synchronization Plists Lec 12 Pickers

Pickers - 1 What/why? A tab bar picker –example Lec 12 Pickers

Tab 3 Date Picker Ivars? Properties? Outlets? Actions? *note: –Date/Time format Lec 12 Pickers

DatePicker Change datePicker Mode buttonPressed details –Raw date – use description –Formatted date: NSDateFormatter Lec 12 Pickers

NSDateFormatter Formatting dates converting string  dates –setDateStyle –setDateFormat –Examples: setDateStyle:NSDateFormatterShortStyle Lec 12 Pickers

DatePicker Setting the datePicker date - (void) setDate: (NSDate*) date animated:(BOOL)animated Where? Lec 12 Pickers

Tab 4 Custom Picker Ivars? Properties? Outlets? Actions? *note: –Date/Time format Lec 12 Pickers

Tab 4 Custom Picker Terminology: rows, components text or images (views) Lec 12 Pickers

Tab 4 Custom Picker Delegates again –Set in IB UIPickerViewDelegate UIPickerViewDataSource picker will ‘request’ data to be displayed as it is needed from the delegate. Lec 12 Pickers

Custom Picker Data source #1. Static NSArray –Initialized where? Data source methods: - (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView -(NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component { return [cityData count]; } Lec 12 Pickers

Tab 4 Custom Picker PickerView Delegate methods: -(NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component Optional: --(void) pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component { Lec 12 Pickers

Custom Picker Data source #2 Property lists – app data files Creating a property list. - (void) loadCityDataFromPList { NSBundle *bundle = [NSBundle mainBundle]; NSString *plistPath = [bundle NSArray* cityDataArray = [[NSArray alloc] initWithContentsOfFile:plistPath]; self.cityData = cityDataArray; [cityDataArray release] ;} Called from where? Lec 12 Pickers