iOS Hello World 实现类讲解

2014-10-20

在学校里的师兄创业园中心帮忙做一些关于 iOS 项目，目前还在熟悉使用 Xcode 。还有师兄讲解 iOS 一些空间使用和相关知识。

下面就把一些基本的学习来进行说明，下面展示最近师兄讲解吧。

在 iOS 加载过程中的一些过程使用类相关功能，例如 main.m:

(1)mian.m 代码：

#import <UIKit/UIKit.h>
#import "AppDelegate.h"

int main(int argc, char * argv[]) {
    @autoreleasepool {
        return UIApplicationMain(argc, argv, nil, NSStringFromClass([AppDelegate class]));
    }
}

上面 #import <UIKit/UIkit.h> 和 #import "AppDelegate.h" 是引入其他的类，和我们在 c 语言中 #include 使用类似。

当前的程序主要是 main 函数中进行执行。

argc ：是 int 类型的参数

argv[] ：是 char 类型的数组指针

@autoreleasepool ：查下资料好像说是什么自动释放池，好像目前不知道什么东东。

UIApplicationMain ：是 iOS 里面的调用接口。

(2)AppDelegate.h 和 AppDelegate.m 代码:

AppDelegate.h

#import <UIKit/UIKit.h>//引入函数库

@interface AppDelegate : UIResponder <UIApplicationDelegate>

@property (strong, nonatomic) UIWindow *window;//参数


@end

@interface 在 Java 开发中我们说的接口

AppDelegate : UIResponder ：是类 AppDelegate 继承自 UIResponder

<UIApplicationDelegate> ：不知道什么鬼？

@property (strong, nonatomic) UIWindow *window; ：局大神使用说这个是类中类似变量相关

@end ：是我们在 Java 中使用来展示类的结束，Java 中结束好像是 }。

下面是 AppDelegate.m 的代码：

#import "AppDelegate.h"//引入的类头文件

@interface AppDelegate ()//类

@end

//类的实现
@implementation AppDelegate

//程序在启动后调用
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    // Override point for customization after application launch.
    return YES;
}

//
- (void)applicationWillResignActive:(UIApplication *)application {
    // Sent when the application is about to move from active to inactive state. This can occur for certain types of temporary interruptions (such as an incoming phone call or SMS message) or when the user quits the application and it begins the transition to the background state.
    // Use this method to pause ongoing tasks, disable timers, and invalidate graphics rendering callbacks. Games should use this method to pause the game.
}

//程序尽心后台运行
- (void)applicationDidEnterBackground:(UIApplication *)application {
    // Use this method to release shared resources, save user data, invalidate timers, and store enough application state information to restore your application to its current state in case it is terminated later.
    // If your application supports background execution, this method is called instead of applicationWillTerminate: when the user quits.
}

//程序在后端进行前端
- (void)applicationWillEnterForeground:(UIApplication *)application {
    // Called as part of the transition from the background to the active state; here you can undo many of the changes made on entering the background.
}

//程序在没有启用或者终止后，调用这个方法
- (void)applicationDidBecomeActive:(UIApplication *)application {
    // Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was previously in the background, optionally refresh the user interface.
}

//程序结束调用
- (void)applicationWillTerminate:(UIApplication *)application {
    // Called when the application is about to terminate. Save data if appropriate. See also applicationDidEnterBackground:.
}

//类的结束
@end

（3）UIViewController.h 和 UIViewController.m:

UIViewController 据师兄说这个类是我们应用在界面中进行实现相关功能的实现。

其中里面的代码如下：

UIViewController.h

#import <UIKit/UIKit.h>//引入 UIKit 框架

@interface ViewController : UIViewController


@end

UIKit ：是我们 iOS 界面相关框架，里面很多控件

ViewController : UIViewController ：继承 UIViewController(视图控制) 的子类

UIViewController.m

#import "ViewController.h"

@interface ViewController ()

@end

@implementation ViewController

//UIViewController 父类中的方法
- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
}

//父类中方法，据说是内存少时调用
- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}


@end

（4）Info.plsit

这个好像是说在项目中进行项目一般的设置参数。

（5）Main.stroyboard

是使用控件来进行界面的控件初始化。

（6）Launchscreen.storyboard

在程序实现过程中登录是显示的界面。

end