IOS开发从hello world开始

学习软件开发少不了讲解hello world，ios hello world小程序对大家肯定没有什么问题了，在这里我用纯代码的方式建立一个Hello world工程，以供ios开发初学者参考了，

首先打开Xcode新建一个empty Application模版，之所以建成空模板是为了从头开始建立一个类似于SingleView Application的模版，然大家熟悉一下建立一个单个窗口程序的过程

建好后项目如下图

接下来需要创建一个基于UIViewController的视图控制器类，取名HelloWroldViewController,

HelloWroldViewController控制着程序的视图,在该类的头文件中添加如下代码以新建一个button，

#import <UIKit/UIKit.h>

@interface HelloWroldViewController : UIViewController
{
    UIButton * helloworldButton;
}
@property(nonatomic,retain)UIButton * helloworldButton;
@end

 

 

HelloWroldViewController.m中添加如下代码 

@synthesize helloworldButton = _helloworldButton;

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
        // Custom initialization
    }
    return self;
}

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view.
    //设置按钮的外观类型
    self.helloworldButton = [UIButton buttonWithType:UIButtonTypeRoundedRect];
    //设置按钮的位置
    self.helloworldButton.frame = CGRectMake(120, 300, 100, 40);
    //设置按钮标题
    [self.helloworldButton setTitle:@"hello world" forState:UIControlStateNormal];
    
    [self.helloworldButton setTitleColor:[UIColor blueColor] forState:UIControlStateNormal];
    [self.view addSubview:self.helloworldButton];
    [self.helloworldButton release];
    
      
}

 

 接下来转到

AppDelegate.h添加如下代码，

@class HelloWroldViewController;
@interface AppDelegate : UIResponder <UIApplicationDelegate>

@property (strong, nonatomic) UIWindow *window;
@property(nonatomic,retain)HelloWroldViewController * rootViewController;

@end

AppDelegate.m文件里引入

#import "HelloWroldViewController.h"
@implementation AppDelegate
@synthesize rootViewController = _rootViewController;
- (void)dealloc
{
    [_window release];
    [_rootViewController release];
    [super dealloc];
}

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    self.window = [[[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]] autorelease];
    // Override point for customization after application launch.
    self.window.backgroundColor = [UIColor whiteColor];

    self.rootViewController = [[HelloWroldViewController alloc]initWithNibName:nil bundle:nil];

    self.window.rootViewController = self.rootViewController;
    [self.window makeKeyAndVisible];
    return YES;
}

最后项目运行图