iOS app startup process

1 I. Uipickerview2 1. Common Properties of Uipickerview3 //data source (used to tell Uipickerview how many columns there are rows)4@property (nonatomic,assign)ID<UIPickerViewDataSource>DataSource;5 //agent (used to tell Uipickerview what to display on every 1 rows of every 1 columns, listen for Uipickerview selection)6@property (nonatomic,assign)ID<UIPickerViewDelegate>Delegate;7 //do you want to display the selected indicator8 @property (nonatomic) BOOL showsselectionindicator;9 //How many columns are there altogether?Ten@property (Nonatomic,ReadOnly) Nsinteger numberofcomponents; One  A 2. Common methods of Uipickerview - //re-refresh all columns -- (void) reloadallcomponents; the //re-refresh column component -- (void) Reloadcomponent: (Nsinteger) component; -  - //the row row of column component is actively selected +- (void) SelectRow: (Nsinteger) Row incomponent: (Nsinteger) component animated: (BOOL) animated; -  + //get the currently selected line number in column component A-(Nsinteger) Selectedrowincomponent: (Nsinteger) component; at  - 3. Data source Method (Uipickerviewdatasource) - //How many columns are there altogether? --(Nsinteger) Numberofcomponentsinpickerview: (Uipickerview *) Pickerview; - //How many lines are there in column component? --(Nsinteger) Pickerview: (Uipickerview *) Pickerview numberofrowsincomponent: (nsinteger) component; in  - 4. Proxy method (Uipickerviewdelegate) to //What is the width of column component? +-(CGFloat) Pickerview: (Uipickerview *) Pickerview widthforcomponent: (nsinteger) component; - //What is the row height of column component ? the-(CGFloat) Pickerview: (Uipickerview *) Pickerview rowheightforcomponent: (nsinteger) component; *  $ //what text is displayed in column component rowPanax Notoginseng-(NSString *) Pickerview: (Uipickerview *) Pickerview Titleforrow: (nsinteger) Row forcomponent: (Nsinteger) component; -  the //section component row row shows what view (content) +-(UIView *) Pickerview: (Uipickerview *) Pickerview Viewforrow: (nsinteger) Row forcomponent: (Nsinteger) component Reusingview: (UIView *) view; A  the //column component row of Pickerview was selected +- (void) Pickerview: (Uipickerview *) Pickerview Didselectrow: (nsinteger) Row incomponent: (Nsinteger) component; -  $ two. Uidatepicker $ 1. Common Properties - //display mode for DatePicker - @property (nonatomic) Uidatepickermode Datepickermode; the //the region language that is displayed -@property (nonatomic, retain) Nslocale *locale;Wuyi  the 2the choice of monitoring Uidatepicker -*because Uidatepicker inherits from Uicontrol, so through Addtarget: ... Monitor Wu  - three. The complete process of program initiation About 1. Main function $  - 2. Uiapplicationmain -*Create a UIApplication object -*Create a uiapplication delegate object A  + 3. Delegate object starts processing (listening) system events (no storyboard) the*when the program is started, the agent's application:didfinishlaunchingwithoptions is called: Method -*Create UIWindow in application:didfinishlaunchingwithoptions: $*Create and set Rootviewcontroller for UIWindow the*Display window the  the 3to obtain the most important storyboard file name according to Info.plist, load the main storyboard (with storyboard) the*Create UIWindow -*Create and set Rootviewcontroller for UIWindow in* Display window

iOS app startup process