[Reprinted]How to show UIDatePicker in UITableViewCell

針對DatePicker已有很多第三方元件，都很棒但不符合目前專案的需求，最終還是使用原生的UIDatePicker打造iPhone行事曆的效果

作法不難，只轉載一些很不賴的參考資訊

iOS Show UIPickerView between UITableViewCells

make uipickerview appear between cells when touched cell

iOS 7 in-line UIDatePicker – Part 1

ToolBar done button action does not work on UIDatePicker

How to show uidatepicker from uitableviewcell

如果要直接用第三方元件，有這些

RMDateSelectionViewController

AIDatePickerController

How to use NSDefault

Primitive Object
// Get
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
NSString* userId = [defaults objectForKey:@"UserId"];
[defaults synchronize];

// Set
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
[defaults setObject:userId forKey:@"UserId"];
[defaults synchronize];

// Clear

NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];

[defaults removeObjectForKey:@"UserId"];

[defaults synchronize];

Custom Object

// Get

NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];

NSData *formData = [defaults objectForKey:@"CustomObject"];

MyCustomData *data=[NSKeyedUnarchiver unarchiveObjectWithData:data];

[defaults synchronize];

// Set

NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];

NSData *data = [NSKeyedArchiver archivedDataWithRootObject:myCustomObject];

[defaults setObject:data forKey:@"CustomObject"];

[defaults synchronize];

// Clear

NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];

[defaults removeObjectForKey:@"CustomObject"];

[defaults synchronize];