Phone. Making a phone call within app ( and returning to app after call ends ) is as easy as :

Transcription

1 Phone Making a phone call within app ( and returning to app after call ends ) is as easy as : -(void)makecall { UIApplication *application = [UIApplication sharedapplication]; NSURL *URL = [NSURL URLWithString: [NSString [application openurl:url options:@{} completionhandler:^(bool success) { if (success) { // NSLog(@ Opened url"); } }]; }

2 Mail In order to send a mail from within the app, we need to implement mail protocol : #import <UIKit/UIKit.h> #import "Reachability.h" #import <MessageUI/MessageUI.h> #import ContactsTableViewController : UITableViewController Reachability BOOL

3 Mail In ContactsTableViewController, we ll use asynchronous version of Reachability to check the network status : switch (status) { case NotReachable: _networkisreachable = NO; break; case ReachableViaWWAN: _networkisreachable = YES; break; } case ReachableViaWiFi: _networkisreachable = YES; break;

4 Mail tableview:didselectrowatindexpath: method, case 1 (mail) calls [self showpicker] method. This method displays an composition interface if MFMailComposeViewController exists and the device can send s.

5 Mail If the device can send s and we have internet connection MailApp is launched. For details, see source code Contacts 2

6

7 MapKit Framework The Map Kit framework provides an interface for embedding maps directly into your own windows and views. This framework also provides support for annotating the map, adding overlays etc

8 Maps Drag and drop another ViewController into Main.storyboard Control-connect ContactsTableViewController to the newly added ViewController and set segue s identifier to showmapsegue

9 Maps From objects library select MapKit View, drag and drop into newly add ViewController. Set MapKit View constraints to (0, 0, 0, 0). Your Main.storyboard should resemble :

10 Maps

11 Maps Since MKMapKit requires network connection, in ContactsViewController, case 2 ( maps ) we have : if(!_networkisreachable) { UIAlertController *alert = [UIAlertController alertcontrollerwithtitle:@"error" message:@"device has no Internet access." preferredstyle:uialertcontrollerstylealert]; UIAlertAction* cancelbutton = [UIAlertAction actionwithtitle:@"ok" style:uialertactionstyledefault handler:^(uialertaction *action) { }];

12 Maps [alert addaction:cancelbutton]; [self presentviewcontroller:alert animated:yes completion:nil]; } else { [self performseguewithidentifier:@"showmapsegue" sender:self]; } break;

13 Maps Create new file MapViewController, subclass of UIViewController In Identity Inspector associate newly add UIViewController with MapViewController Using Assistant editor, create IBOutlet MKMapView *mapview MKMapView requires #import <MapKit/MapKit.h>

14 Maps MKMapView requires #import <MapKit/MapKit.h> Here is the interface : #import <UIKit/UIKit.h> #import MapViewController : (weak, nonatomic) IBOutlet MKMapView

15 Maps In MapViewController.m, viewdidload method, we specify location s latitude and longitude as well as coordinate region : CLLocationCoordinate2D location; location.latitude = ; location.longitude= ; MKCoordinateRegion viewregion = MKCoordinateRegionMakeWithDistance(location, 800, 800); [_mapview setregion:viewregion animated:yes];

16 Maps Run

17 Maps Annotation can be easily added if needed : MKPointAnnotation *annotationpoint = [[MKPointAnnotation alloc] init]; annotationpoint.coordinate = location; annotationpoint.title Technology Centre"; annotationpoint.subtitle Road, St. John\'s NL, A1C 6L8"; [_mapview addannotation:annotationpoint];

18 Maps Run

19 WebKit view WebKit view class can be used to embed web content in your application. To do so, you simply create a WebKit view object, attach it to a window, and send it a request to load web content.

20 WebKit view Back in Main.storyboard, add another view controller, control-connect it from ContactsTableViewController and give segue identifier showwebsegue From objects library drag WebKit view (constraints: 0, 0, 0, 0) into a newly added controller. Your Main.storyboard should resemble :

21

22 WebKit view Create new file WebViewController, subclass of UIViewController and in Identity inspector associate it with the newly added view. Using assistant editor create an IBOutlet : #import <UIKit/UIKit.h> #import WebViewController : (weak, nonatomic) IBOutlet WKWebView

23 WebKit view In WebViewController.m, viewdidload method we have : NSURL *url = [NSURL URLWithString:@" NSURLRequest *urlrequest = [NSURLRequest requestwithurl:url]; [_webview loadrequest:urlrequest]; As before, in ContactsTableViewController, we perform segue conditionally:

24 WebKit view Run.

25 WebKit view Class containing WKWebView can implement WKNavigationDelegate. It is recommended that, whenever accessing network, indicator should appear in the header. So, in ContactsViewController we start the network activity indicator before the page is loaded : [[UIApplication sharedapplication] setnetworkactivityindicatorvisible: YES];

26 WebKit view In WebViewController.h we specify that class will implement delegate WebViewController : UIViewController <WKNavigationDelegate> Implementation, viewdidload, specifies webview as its own delegate : [_webview setnavigationdelegate:self];

27 WebKit view And implements method : - (void)webview:(wkwebview *)webview didfinishnavigation:(wknavigation *)navigation { [[UIApplication sharedapplication] setnetworkactivityindicatorvisible: NO]; }

28 WebKit view Starting with ios 9, App Transport Security blocks insecure cleartext HTTP. Temporary exceptions can be configured via Info.plist file. For ios 9 and higher, open Info.plist as source and at the end of the file (before </dict> and </ plist> add:

29 WebKit view <key>nsapptransportsecurity</key> <dict> <key>nsallowsarbitraryloads</key> <true/> <key>nsexceptiondomains</key> <dict/>

30 UICollectionView The Collection View and Flow Layout provide a new, flexible way to present content to the user. The UICollectionView class is responsible for managing the data items that are to be displayed to the user.

31 UICollectionView The collection view instance needs a data source object from which to obtain the data items to be displayed, together with a delegate object to handle user interaction with the collection. These objects must implement the UICollectionViewDataSource and UICollectionViewDelegate protocols respectively.

32 UICollectionViewCell The UICollectionViewCell class is responsible for displaying whatever data is provided to the UICollectionView instance by the data source with one cell corresponding to one data item.

33 UICollectionViewCell There is a clear separation between layout and the contents of a cell. The cell only knows what to display, the sizing and positioning of the cell within the wider context of the collection view is controlled by the layout object assigned to the collection view.

34 Demo Create new project, single view, name Collection View In Main.storyboard, from object library, drag and drop collection view. Control-connect collection view to controller s outlets datasource and delegate.

35 Demo In Attribute inspector set the number of collection view s items to 1. Set ConnectionView s constraints to (0, 0, 0, 0) In Size Inspector, set Min Spacing for Cells and Lines to 0.

36 Demo Select the cell and in Size Inspector, set it to custom size, say, by (iphone 8) In Attributes Inspector, set cell s identifier to datacell From object s library drag and drop image view into the cell at (5, 5), size (177.5, 267.5), constraints to (5, 5, 5, 5). Your Main.storyboard should resemble :

37 Demo Copy images amadeus.jpg, exorcist.jpg, godfather.jpg, jaws.jpg, lord.jpg and scarface.jpg into Project folder.

38 Delegate and Datasource Using Assistant editor, control-connect UICollectionView to ViewController.h and create outlet collectionview. For the data source we ll need NSArray *data :

39 Delegate and Datasource #import ViewController : UIViewController <UICollectionViewDataSource, (strong, nonatomic) IBOutlet UICollectionView (strong, nonatomic) NSArray

40 Delegate and Datasource Create new file CustomCollectionViewCell, subclass of UICollectionViewCell. Using identity inspector, associate UIViewCollectionCell with the newly created class CustomCollectionViewCell.

41 Delegate and Datasource Using Assistant editor, control-connect UIImageView and create an outlet imageview : #import CustomCell : (strong, nonatomic) IBOutlet UIImageView

42 Delegate and Datasource Back to ViewController.m, in viewdidload method we populate array data : _data = @ lord.jpg, nil]; Now we have to implement data source and delegate methods.

43 Delegate and Datasource Our collection view has a single section : -(NSInteger)numberOfSectionsInCollectionView: (UICollectionView *)collectionview { return 1; } Number of items in sections is : -(NSInteger)collectionView:(UICollectionView *)collectionview numberofitemsinsection:(nsinteger)section { return _data.count; }

44 Delegate and Datasource Define the cell : -(UICollectionViewCell *) collectionview:(uicollectionview *)collectionview cellforitematindexpath:(nsindexpath *)indexpath { CustomCollectionViewCell *cell = [collectionview dequeuereusablecellwithreuseidentifier:@"datacell" forindexpath:indexpath]; cell.imageview.image = [UIImage imagenamed: [_data objectatindex:indexpath.row]]; } return cell;

45 Delegate and Datasource Specify cell s width and height: - (CGSize)collectionView:(UICollectionView *)collectionview layout:(uicollectionviewlayout *)collectionviewlayout sizeforitematindexpath:(nsindexpath *)indexpath { CGFloat width = self.view.frame.size.width / 2.0; CGFloat height = 1.44 * width; } return CGSizeMake(width, height);

46 Demo Run.

47 Calendar Our next project will use UICollectionView to display calendar. Create a new project, single view, name Calendar Add Navigation Controller, connect it to the existing view and delete TableView Controller.

48 Calendar Add seven labels (System 12.0), select them all and create horizontal stack, background color RGB (249, 249, 249) Set constraints for the horizontal stack: left (0), top (0), right (0) and height (28). Control connect labels (S - M, M - T, etc.) and set constraint to equal widths.

49 Calendar Under the horizontal stack, place UICollectionView at (0, 92) and set constraints to (0, 0, 0, 0). In Attribute Inspector set Items to 1 and in Accessories select Section Header, Min Spacing for cells and lines to 0. Inside cell and header, place labels ( for month and day ). Set header s height to 32.

50 Calendar Header s label size is (120, 20), font: System 16.0, Constraints: vertically aligned, left >=, height 20, right 8. Cell s label size is (24, 24) horizontally and vertically centered in container, font: System 17.0 Using Identity Inspector, set cell s identifier to calendarcell and header s identifier to calendarheader.

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52 Calendar We need two custom classes for the header and cell : #import HeaderCollectionReusableView : (weak, nonatomic) IBOutlet UILabel #import CalendarCollectionViewCell : (weak, nonatomic) IBOutlet UILabel

53 Calendar In Main.storyboard, Identity Inspector, associate header and cell with custom classes HeaderCollectionReusableView and CalendarCollectionViewCell, respectively. Control-connect UICollectionView (calendarcollectionview) to the View Controller and set both, datasource and delegate.

54 Calendar Also create an outlet for the top stack. Declare NSMutableArray months. Our ViewController must implement UICollectionView s data source and delegate methods.

55 Calendar This is our ViewController.h : #import ViewController : UIViewController <UICollectionViewDelegate, (weak, nonatomic) IBOutlet UIStrackView (weak, nonatomic) IBOutlet UICollectionView (strong, nonatomic) NSMutableArray

56 Calendar In viewdidload method, we declare and initialize several NSArrays ( storing dates for months ) and add them to mutable array months. _months = [[NSMutableArray alloc] init]; [_months addobject:jan]; [_months addobject:feb]; [_months addobject:mar];

57 Calendar The number of sections in our UICollectionView is the number of months : -(NSInteger)numberOfSectionsInCollectionView: (UICollectionView *)collectionview { return _months.count; }

58 Calendar The number of items in each section is the number of days in month : -(NSInteger)collectionView:(UICollectionView *)collectionview numberofitemsinsection:(nsinteger)section { NSArray *temp = [_months objectatindex:section]; return temp.count; }

59 Calendar Cells are created in pretty much the same way as in UITableView : -(UICollectionViewCell *)collectionview: (UICollectionView *)collectionview cellforitematindexpath: (NSIndexPath *)indexpath { CalendarCell *cell = [collectionview dequeuereusablecellwithreuseidentifier:@"calendarcell" forindexpath:indexpath];

60 Calendar NSArray *temp = [_months objectatindex:indexpath.section]; cell.datenumber.text = [temp objectatindex:indexpath.row]; } if(indexpath.row % 7 == 0 (indexpath.row + 1) % 7 == 0) cell.datenumber.textcolor = [UIColor lightgraycolor]; else cell.datenumber.textcolor = [UIColor blackcolor]; return cell;

61 Calendar Header is somewhat different though: - (UICollectionReusableView *)collectionview: (UICollectionView *)collectionview viewforsupplementaryelementofkind:(nsstring *)kind atindexpath:(nsindexpath *)indexpath { UICollectionReusableView *reusableview = nil; if (kind == UICollectionElementKindSectionHeader) { HeaderCollectionReusableView *headerview = [collectionview dequeuereusablesupplementaryviewofkind: UICollectionElementKindSectionHeader withreuseidentifier:@"header" forindexpath:indexpath];

62 Calendar Now you can customize header view, for example adding a border under the header : UIView *bottomborder = [UIView new]; bottomborder.backgroundcolor = [UIColor lightgraycolor]; bottomborder.frame = CGRectMake(0, headerview.frame.size.height - 1, headerview.frame.size.width, 1); [headerview addsubview:bottomborder]; Finally, return reusable view : return reusableview;

63 Calendar Size of cells is defined in sizeforitematindexpath method: CGFloat width = self.view.frame.size.width / 7.0; CGFloat height = width; In order to handle Portrait/Landscape orientation, implement viewwilllayoutsubviews method.

64 Calendar Run. ( Calendar 1 )

65 Calendar Populating calendar manually isn t the best solution, is it? So, let s use NSCalendar instead. In View Controller we ll need several properties (nonatomic, strong) NSCalendar (nonatomic, strong) NSDate (nonatomic, strong) NSDate (nonatomic, strong) NSDate NSInteger initialsection; In viewdidload method we create calendar, date and date components ( required for accessing days, months, years etc. ) :

66 Calendar if (!_calendar) { [self setcalendar:[nscalendar currentcalendar]]; } _date = [[NSDate alloc] init]; NSDateComponents *components = [_calendar components: NSCalendarUnitYear NSCalendarUnitMonth NSCalendarUnitDay fromdate:_date]; Next we set the initial section of our UICollectionView to the current month : long year = components.year; long month = components.month; _initialsection = (year ) * 12 + month - 1;

67 Calendar The range of our calendar is [ January 2000, December current year + 9 ] : components.day = 1; components.month = 1; components.year = 2000; _firstdate = [_calendar datefromcomponents:components]; components.year = year + 10; components.day = -1; _lastdate = [_calendar datefromcomponents:components];

68 Calendar We want to set initial section to the current month of the current year. For that we set boolean variable: BOOL _viewdidlayoutsubviewsforthefirsttime = YES; We scroll into the initial section in viewdidlayoutsubviews method:

69 Calendar - (void)viewdidlayoutsubviews { [super viewdidlayoutsubviews]; if (_viewdidlayoutsubviewsforthefirsttime) { _viewdidlayoutsubviewsforthefirsttime = NO; UICollectionViewLayoutAttributes *attributes = [_calendarcollectionview layoutattributesforitematindexpath: [NSIndexPath indexpathforrow:0 insection:_initialsection]]; } } CGRect rect = attributes.frame; [_calendarcollectionview setcontentoffset:cgpointmake( _calendarcollectionview.frame.origin.x, rect.origin.y - 32) animated:no];

70 Calendar We ll need a couple of calendar helper methods : - (NSDate *)firstofmonthforsection:(nsinteger)section { NSDateComponents *offset = [NSDateComponents new]; offset.month = section; } return [_calendar datebyaddingcomponents:offset todate:_firstdate options:0]; Which returns the date of the first day in a month depending on UICollectionView s section. Method dateforcellatindexpath returns the date for each cell.

71 Calendar - (NSDate *)dateforcellatindexpath:(nsindexpath *)indexpath { NSDate *firstofmonth = [self firstofmonthforsection:indexpath.section]; NSInteger ordinalityoffirstday = [_calendar ordinalityofunit:nscalendarunitday inunit:nscalendarunitweekofmonth fordate:firstofmonth]; NSDateComponents *datecomponents = [NSDateComponents new]; datecomponents.day = (1 - ordinalityoffirstday) + indexpath.item; } return [_calendar datebyaddingcomponents:datecomponents todate:firstofmonth options:0];

72 Calendar Now the number of sections is : -(NSInteger)numberOfSectionsInCollectionView: (UICollectionView *)collectionview { return [_calendar components:nscalendarunitmonth fromdate:_firstdate todate:_lastdate options:0].month + 1; }

73 Calendar Number of items ( dates ) per section : -(NSInteger)collectionView:(UICollectionView *)collectionview numberofitemsinsection:(nsinteger)section { NSDate *firstofmonth = [self firstofmonthforsection:section]; NSRange rangeofweeks = [_calendar rangeofunit:nscalendarunitweekofmonth inunit:nscalendarunitmonth fordate:firstofmonth]; } int daysperweek = 7; return (rangeofweeks.length * daysperweek);

74 Calendar Cells are assigned values : NSDate *celldate = [self dateforcellatindexpath:indexpath]; NSDateComponents *celldatecomponents = [_calendar components:nscalendarunitday NSCalendarUnitMonth NSCalendarUnitYear fromdate:celldate]; NSDateFormatter *dateformatter; dateformatter = [[NSDateFormatter alloc] init]; dateformatter.dateformat day = [dateformatter stringfromdate:celldate]; cell.datenumber.text = day;

75 Calendar We also set current day s cell background to red and corner radius to 12.0 (since Label s frame is 24x24) cell.datenumber.layer.cornerradius = 12.0; cell.datenumber.clipstobounds = YES; if(celldatecomponents.day == todaycomponents.day && celldatecomponents.month == todaycomponents.month && celldatecomponents.year == todaycomponents.year) { } cell.datenumber.backgroundcolor = [UIColor redcolor]; cell.datenumber.textcolor = [UIColor whitecolor];

76 Calendar Header is handled similarly : NSDateFormatter *headerdateformatter = [[NSDateFormatter alloc] init]; headerdateformatter.calendar = _calendar; headerdateformatter.dateformat = [NSDateFormatter dateformatfromtemplate:@"yyyy LLLL" options:0 locale:_calendar.locale]; NSString *headertitle = [headerdateformatter stringfromdate:[self firstofmonthforsection: indexpath.section]].uppercasestring; headerview.month.text = headertitle; reusableview = headerview;

77 Calendar It would be nice to get back instantly to the current month / date. Back to Main.storyboard, grab Toolbar from Object library and drag it into the View Controller, bottom position, constraints (left:0, bottom 0, right 0, height: 44)

78 Calendar Change button s title to Today and using Assistant editor create IBAction todaybutton : - (IBAction)todayButton:(id)sender;

79 Calendar Finally, implement the code for todaybutton ( similar to viewwilladdsubviews - set section to initial section ) : - (IBAction)todayButton:(id)sender { UICollectionViewLayoutAttributes *attributes = [_calendarview layoutattributesforitematindexpath: [NSIndexPath indexpathforrow:0 insection:_initialsection]]; } CGRect rect = attributes.frame; [_calendarview setcontentoffset: CGPointMake(_calendarView.frame.origin.x, rect.origin.y - 32) animated:no];

80 Calendar Run. ( Custom Calendar 2 )

81 Calendar How would one populate calendar with custom events? First of all, we need a label under the date ( quite tiny 6x6 ). Set constraints to width:6, height: 6, bottom: 2, horizontally centered in container.

82 Calendar Using Assistant Editor create IBOutlet UILabel event and declare boolean property hasevent : #import CalendarCollectionViewCell : (weak, nonatomic) IBOutlet UILabel (strong, nonatomic) IBOutlet UILabel BOOL

83 Calendar Implementation ( CallendarCollectionViewCell.m ) will require prepareforreuse method : - (void)prepareforreuse { [super prepareforreuse]; } _event.backgroundcolor = [UIColor clearcolor]; _event.textcolor = [UIColor blackcolor]; _datenumber.backgroundcolor = [UIColor clearcolor]; _datenumber.textcolor = [UIColor blackcolor]; _hasevent = NO;

84 Calendar In ViewController we declare couple of properties (nonatomic, strong) NSMutableArray (nonatomic, strong) NSDate *selecteddate; In implementation, viewdidload method, create and populate events: _events = [[NSMutableArray alloc] init]; [_events addobject:@" "]; [_events addobject:@" "]; [_events addobject:@" "]; [_events addobject:@" "];

85 Calendar Now we have to implement several delegate methods that handle cell selection : shouldselectitematindexpath: - do not select invisible cells ( those that belong to previous / next month )

86 Calendar didselectitematindexpath: - change date s background colour to grey circle / white text and set the value of selected date. diddeselectitematindexpath: - reset dates background / text colour and handle current date s background colour.

87 Calendar Several helper methods are required as well : isenableddate: - which determines whether the date is selectable or not ( uses in turn clampdate: method ).

88 Calendar isselecteddate: - which determines whether the date is selected or not ( uses in turn clampandcomparedate: method ). istodaydate: - which determines whether the date is today date or not ( uses in turn clampandcomparedate: method ).

89 Calendar Run. ( Custom Calendar 3 )

90 Calendar In order to display event we need a new UIViewController - EventViewController. Create new file and in Identity Inspector associate it with the newly added view controller. Add UILabel (left: 24, top: 68, right: 24, height: 21) and in Assistant Editor create an IBOutlet. Also declare property stringdate.

91 Calendar #import EventViewController : (weak, nonatomic) IBOutlet UILabel (strong, nonatomic) NSString

92 Calendar Since not every cell has an event, we cannot simply connect two controllers - we have to do it programatically. Select the newly added view controller and in Identity Inspector assigned it an ID eventcontroller. Your Main.storyboard should resemble :

93 Calendar

94 Calendar In ViewController, implement didselectitematindexpath: if(cell.hasevent) { NSDateFormatter *formatter = [[NSDateFormatter alloc] init]; formatter.dateformat MMMM d, yyyy"; NSDate *celldate = [self dateforcellatindexpath:indexpath]; NSString *stringdate = [formatter stringfromdate:celldate]; EventViewController *events = [self.storyboard events.stringdate = stringdate; } [self.navigationcontroller pushviewcontroller: events animated:yes];

95 Calendar In EventViewController, implement viewdidload - (void)viewdidload { [super viewdidload]; } self.title _datelabel.text = _stringdate; Run. ( Custom Calendar 4 )

96

97 Tab Bar Controller A tab bar is a control, usually appearing across the bottom of the screen in the context of a tab bar controller, for giving the user one-tap, modal access to a set of views in an app. Each button in a tab bar is called a tab bar item and is an instance of the UITabBarItem class.

98 Tab Bar Controller Create new project, single view, delete default view controller and drag from object library Tab Bar Controller into Main.storyboard.

99 Tab Bar Controller By default, Xcode creates two view controllers. Using Attribute Inspector, set Tab Bar Controller to be the initial view controller. Put couple of labels for each view ( Home, Music )

100 Tab Bar Controller Additional controllers can be added. Drag navigation controller into Main.storyboard. In Table View, set cell s reusable identifier. Control-connect Tab Bar Controller to the Navigation Controller, select Relationship segue: view controllers.

101 Tab Bar Controller

102 Tab Bar Controller Create new class TabBarViewController subclass of UITabBarController. In Identity inspector associate Tab Bar Controller with the newly created class. In order to define text/icons in viewdidload we have :

103 Tab Bar Controller UITabBar *tabbar = self.tabbar; UITabBarItem *tabbaritem1 = [tabbar.items objectatindex:0]; UITabBarItem *tabbaritem2 = [tabbar.items objectatindex:1]; UITabBarItem *tabbaritem3 = [tabbar.items objectatindex:2]; tabbaritem1.title tabbaritem2.title tabbaritem3.title tabbaritem1.image = [UIImage imagenamed:@"home"]; tabbaritem2.image = [UIImage imagenamed:@"music"]; tabbaritem3.image = [UIImage imagenamed:@"movie"]; Run.

104

105 Tab Bar Controller Sometimes we might have to pass data to navigation controller(s). Create new file MovieTableViewController subclass of UITableView controller and associate it with table view, set cell s id to moviecell. In both, TabBarViewController.h and MovieTableViewController.h declare (strong, nonatomic) NSArray *titles;

106 Tab Bar Controller In TabBarViewController.n we access the navigation controller and set movie titles: UINavigationController *nav; nav = [self.viewcontrollers objectatindex:2]; MovieTableViewController *movietableviewcontroller = (MovieTableViewController*) [nav.viewcontrollers objectatindex:0]; of the Scarface"]; movietableviewcontroller.titles = _titles;

107 Tab Bar Controller In MovieTableViewController.n we implement delegate / data source methods: - (NSInteger)numberOfSectionsInTableView: (UITableView *)tableview { } return 1; - (NSInteger)tableView:(UITableView *)tableview numberofrowsinsection:(nsinteger)section { } return [_titles count];

108 Tab Bar Controller - (UITableViewCell *)tableview:(uitableview *)tableview cellforrowatindexpath:(nsindexpath *)indexpath { UITableViewCell *cell = [tableview dequeuereusablecellwithidentifier:@"moviecell" forindexpath:indexpath]; cell.textlabel.text = [_titles objectatindex:indexpath.row]; } return cell; Default color for icons/text in TabBar can be chaged: tabbar.tintcolor = [UIColor colorwithred:255.0/255.0 green:0.0/255.0 blue:0.0/255.0 alpha:1];

109 Tab Bar Controller

110 UISegmentedControl Similar to UITabBarController, although somewhat simpler. It is a horizontal control made of multiple segments, each segment functioning as a discrete button. A segmented control affords a compact means to group together a number of controls.

111 Segmented Control Create new project and in Main storyboard add Segmented Control and Label. Using assistant editor, create IBAction segmentswitch on Segmented Control and IBOutlet output on Label.

112 segmentswitch - (IBAction)segmentSwitch:(id)sender { } UISegmentedControl *segmentedcontrol = (UISegmentedControl *) sender; NSInteger selectedsegment = segmentedcontrol.selectedsegmentindex; if(selectedsegment == 0) _output.text Segment"; else _output.text Segment";

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114 UISegmentedControl For more complex layouts one might want to use Container Views. Drag couple of container views into View Controller (same size and constraints). Observe that there is a view controller associated with each container view.

115 UISegmentedControl Change views background colors and add couple of labels. Set proper constraints. Your Main storyboard should resemble:

116

117 UISegmentedControl In viewdidload method we set the initial view to the _firstview by setting its alpha component to 1 (visible) and second view s to 0 (invisible) _firstview.alpha = 1; _secondview.alpha = 0; Similar thing happens in segmentswitch method.

118 - (IBAction)segmentSwitch:(id)sender { } UISegmentedControl *segmentedcontrol = (UISegmentedControl *) sender; NSInteger selectedsegment = segmentedcontrol.selectedsegmentindex; if(selectedsegment == 0) { _firstview.alpha = 1; _secondview.alpha = 0; } else { _firstview.alpha = 0; _secondview.alpha = 1; }

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120 UISegmentedControl and UITableView Sometimes single table needs to be populated with different data sets based on the state of segmented control. Add UITableView under segmented control, set its constraints and using Connection Inspector connect Delegate and DataSource to ViewController.

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122 UISegmentedControl and UITableView Using Assistant editor, create IBOutlet tableview. Also, in ViewController.h declare three NSArrays.

123 #import ViewController : UIViewController <UITableViewDataSource, UITableViewDelegate> - (weak, nonatomic) IBOutlet UITableView (strong, nonatomic) NSArray (strong, nonatomic) NSArray (strong, nonatomic) NSArray

124 UISegmentedControl and UITableView In implementation, viewdidload method, initialize arrays and set delegate: _data = _firstdataset; [_tableview setdelegate:self];

125 UISegmentedControl and UITableView Implement delegate/datasource methods. Cell label s text is set to: [_data objectatindex (NSUInteger)indexPath.row]; Data sets are changed in segmentswitch method:

126 - (IBAction)segmentSwitch:(id)sender { } UISegmentedControl *segmentedcontrol = (UISegmentedControl *) sender; NSInteger selectedsegment = segmentedcontrol.selectedsegmentindex; if(selectedsegment == 0) { _data = _firstdataset; } else { _data = _seconddataset; } [_tableview reloaddata];

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128 Files and Directories ios is, well, OS and consequently has a file system. Each ios application on a device has its own private Documents and tmp directories into which it is permitted to read and write data.

129 Files and Directories The Foundation Framework provides three classes that are indispensable when it comes to working with files and directories: NSFileManager, NSFileHandle and NSData

130 NSFileManager The NSFileManager class can be used to perform basic file and directory operations such as creating, moving, reading and writing files and reading and setting file attributes. In addition, this class provides methods for identifying the current working directory, changing to a new directory, creating directories and listing the contents of a directory.

131 NSFileManager NSFileManager *filemgr = [NSFileManager defaultmanager]; NSArray *dirpaths = NSSearchPathForDirectoriesInDomains( NSDocumentDirectory, NSUserDomainMask, YES ); NSString *docsdir = dirpaths[0];

132 Files Once the path to Documents directory has been found, specified file ( e.g. datafile.dat ) can be created, opened etc. NSString *filename = [docsdir

133 Files if ([filemgr fileexistsatpath: filename]) { NSData *databuffer = [filemgr contentsatpath: filename]; NSString *datastring = [[NSString alloc] initwithdata:databuffer encoding:nsasciistringencoding]; } else { [filemgr createfileatpath: filename contents: nil attributes: nil]; }

134 Files In order to write to a file, we ll use : NSString *content = This is a file content ; [content writetofile:filename atomically:no encoding: NSStringEncodingConversionAllowLossy error:nil];

135

136 SQLite SQLite is an embedded, relational database management system (RDBMS). SQLite is written in the C programming language and therefore using SQLite on ios involves direct calls to C functions and access to C data structures. Create new project ( SQLite Demo ), single view application and in targets, Build Phases, add SQLite library libsqlite3.0.tbd

137 SQLite In ViewController.h we need to import sqlite3.h and declare pointer to database contactdb as well as databasepath : #import <UIKit/UIKit.h> #import (strong, nonatomic) NSString (nonatomic) sqlite3

138

139 SQLite Textfields are 189 x 30 at 94, 140 and 186, horizontally centered. Label is 568 x 21 at 248. Constraints (L:16, T:32, R:16, height: 21). Segmented control is 123 x 29 at 301, horizontally centered, neither segment initially selected. Constraints (T:32, WH)

140 SQLite Create four IBOutlets (name, address, phone and status) for three text fields and one label. Create IBAction savefind for segmented control

141 SQLite #import <UIKit/UIKit.h> #import ViewController : (strong, nonatomic) IBOutlet UITextField (strong, nonatomic) IBOutlet UITextField (strong, nonatomic) IBOutlet UITextField (strong, nonatomic) IBOutlet UILabel *status; - (strong, nonatomic) NSString (nonatomic) sqlite3

142 SQLite As in the case of files, in viewdidload method, first of all we have to see if database contacts.db exists : NSArray *dirpaths = NSSearchPathForDirectoriesInDomains( NSDocumentDirectory, NSUserDomainMask, YES); NSString *docsdir = dirpaths[0]; _databasepath = [[NSString alloc] initwithstring: [docsdir stringbyappendingpathcomponent:@"contacts.db"]]; NSFileManager *filemgr = [NSFileManager defaultmanager];

143 SQLite If DB does not exist, we will create it using the sqlite3_open(dbpath, &_contactdb) method and also create table CONTACTS : if ([filemgr fileexistsatpath: _databasepath ] == NO) { const char *dbpath = [_databasepath UTF8String]; if (sqlite3_open(dbpath, &_contactdb) == SQLITE_OK) { char *errmsg; const char *sql_stmt = "CREATE TABLE IF NOT EXISTS CONTACTS (NAME TEXT, ADDRESS TEXT, PHONE TEXT)";

144 SQLite } if (sqlite3_exec(_contactdb, sql_stmt, NULL, NULL, &errmsg)!= SQLITE_OK) { _status.text to create table"; } sqlite3_close(_contactdb); } else { _status.text to open/create database"; }

145 SQLite sqlite3_exec() method takes five arguments: 1. sqlite3 * open database 2. const char *sql string representing SQL statement to be evaluated

146 SQLite 3. int(*callback)(void *, int, char **, char **) callback function ( number of columns, actual values etc, unless NULL ) 4. void * result column(s), unless NULL 5. char **errmsg error message

147 SQLite The saving/finding of contact data to the database is the responsibility of the savefind action method. Statement is defined as in: NSString *querysql * FROM contacts"; const char *query_stmt = [querysql UTF8String];

148 SQLite Query is executed through sqlite3_prepare_v2(), sqlite3_step() and sqlite3_finalize() functions. See source code for details. sqlite3_prepare_v2(_contactdb, query_stmt, -1, &statement, NULL); sqlite3_step(statement); sqlite3_finalize(statement);

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