2018-04-26

#import "ViewController.h"

@interface ViewController ()

//类变量的声明

@end

// 类属性声明

// 类方法和声明

@implementation ViewController

- (void)viewDidLoad {

    [super viewDidLoad];

    // Do any additional setup after loading the view, typically from a nib.

}

- (void)didReceiveMemoryWarning {

    [super didReceiveMemoryWarning];

    // Dispose of any resources that can be recreated.

}

@end

在这里两种方法实现UIViewController类的基类中定义

初始视图加载后调用viewDidLoad中的安装程序

在内存警告的情况下调用didReceviveMemoryWarning