XCode:iPhone:Basic

lastmod 2021-03-31created 2021-03-315 edits

Basics of iPhone app development in XCode.

Info

How to add a button touch-down event in Version 12.4 (12D4e)

Creating a project

Select iOS > App.

Getting started with the storyboard

To place controls such as buttons on the storyboard, select View > Show Library from the menu. (Shortcut: Command + Shift + L)

Button

First, click the "Add Editor on Right" button at the top right of the editor to split the code pane and the storyboard pane.

Right-click the button control, left-click Send Events > Touch Down, and drag it into the class in ViewController.h to add an event.

Label

Right-click the label -> drag, or

in the right-click popup -> left-click Reference Outlets > New Referencing Outlet and drag it into the class in ViewController.h to add an object reference.

Final code

ViewController.h:

#import <UIKit/UIKit.h>

@interface ViewController : UIViewController

@property (weak, nonatomic) IBOutlet UILabel *label;

- (IBAction)touchDown:(id)sender;

@end

ViewController.m:

#import "ViewController.h"

@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view.
}

- (IBAction)touchDown:(id)sender {
    [self.label setText: @"MyLabel!"];
}

@end

Adding a library

Select the top-level project file, select the General tab, click the + button in the Frameworks, Libraries, and Embedded Content section, and select from the list.