自定义视图,视图控制器的生命周期

1.自定义视图

#import "MyView.h"

@implementation MyView


//重写父类的初始化方法

-(instancetype)initWithFrame:(CGRect)frame
{
    if(self = [super initWithFrame:frame]){
     //切记引用,如果不写的话则没办法调用
        [self setView_up];
    }
    return self;
}
//私有方法布局
-(void)setView_up{

    //设置位置
    self.leftLable =[[UILabel alloc]initWithFrame:CGRectMake(20, 20, 80, 40)];
    //设置颜色
    //self.leftLable.backgroundColor = [UIColor magentaColor];
    //设置字体
    self.leftLable.text = @"用户名";
    self.leftLable.font = [UIFont systemFontOfSize:16];
    //对齐方式-----居中
    self.leftLable.textAlignment = NSTextAlignmentCenter;
    //添加
    [self addSubview:self.leftLable];
    
    self.rightTextField = [[UITextField alloc] initWithFrame:CGRectMake(self.leftLable.frame.origin.x + self.leftLable.frame.size.width + 20,self.leftLable.frame.origin.y,self.frame.size.width - self.leftLable.frame.size.width - 40,self.leftLable.frame.size.height)];
    self.rightTextField.placeholder = @"请输入用户信息";
    //self.rightTextField.backgroundColor = [UIColor grayColor];
    self.rightTextField.borderStyle = 3;
    self.rightTextField.delegate = self;    
    [self addSubview:self.rightTextField];
    
}
-(BOOL)textFieldShouldReturn:(UITextField *)textField
{
    [textField resignFirstResponder];
    return YES;
}

@end

2.ViewController的声明周期

#import "ViewController.h"
#import "MyView.h"
@interface ViewController ()
//@property (strong,nonatomic) MyView *myView;
@end

@implementation ViewController
//系统封装了了初始化方法,每次运行都会先调用初始化方法
-(instancetype)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    if (self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil]) {
        NSLog(@"这个方法被调用了");
        NSLog(@"%s",__FUNCTION__);//打印当前被调用的方法的名称
    }
    return self;
   
}
//加载视图,用以代码布局的时候被调用,当视图第一次载入的时候调用的方法,企业级的面试题之一,ViewController的生命周期,加载视图到内存再到显示再到视图,加载->内存->显示->视图->消失->内存->dealloc
-(void)loadView
{
    [super loadView];
    //__LINE__,方法被调用时所在的代码行数
    NSLog(@"%s %d",__FUNCTION__,__LINE__);
}
//加载完毕
-(void)viewDidLoad
{
    NSLog(@"%s",__FUNCTION__);
    //self.view.backgroundColor = [UIColor redColor];
    //背景图,ViewController自带一个view
    UIView *backView = [[UIView alloc] initWithFrame:self.view.frame];
    backView.backgroundColor = [UIColor greenColor];
    [self.view addSubview:backView];
    //创建MyView对象
    MyView *userName = [[MyView alloc] initWithFrame:CGRectMake(10, 10, 300, 70)];    
    userName.leftLable.text = @"用户名";
    //userName.backgroundColor = [UIColor magentaColor];
    NSLog(@"%@",NSStringFromCGRect(userName.rightTextField.frame));
    [backView addSubview:userName];
    
    userName.rightTextField.placeholder = @"请输入用户名";
    
    MyView *userPassword = [[MyView alloc] initWithFrame:CGRectMake(userName.frame.origin.x, userName.frame.origin.y + 100, userName.frame.size.width, userName.frame.size.height)];
    userPassword.leftLable.text = @"密码";
    userPassword.rightTextField.placeholder = @"请输入密码";
    userPassword.rightTextField.keyboardType =  UIKeyboardTypeASCIICapable;
    userPassword.rightTextField.secureTextEntry = YES;
    //userPassword.backgroundColor = [UIColor magentaColor];
    [backView addSubview:userPassword];
    
    MyView *userPhone = [[MyView alloc] initWithFrame:CGRectMake(userPassword.frame.origin.x, userPassword.frame.origin.y + 100, userName.frame.size.width, userName.frame.size.height)];
    userPhone.leftLable.text = @"手机号";
    userPhone.rightTextField.placeholder = @"请输入手机号";
    userPhone.rightTextField.keyboardType =  UIKeyboardTypeASCIICapable;
    [backView addSubview:userPhone];
    
    MyView *userEmail = [[MyView alloc] initWithFrame:CGRectMake(userPhone.frame.origin.x, userPhone.frame.origin.y + 100, userName.frame.size.width, userName.frame.size.height)];
    userEmail.leftLable.text = @"邮箱";
    userEmail.rightTextField.placeholder = @"请输入邮箱号";
    userEmail.rightTextField.keyboardType =  UIKeyboardTypeASCIICapable;
    [backView addSubview:userEmail];
    }
//视图将要显示
-(void)viewWillAppear:(BOOL)animated
{
    NSLog(@"%s, %d",__FUNCTION__,__LINE__);
}
//视图已经出现
-(void)viewDidAppear:(BOOL)animated
{
    NSLog(@"%s",__FUNCTION__);
}
//视图将要消失
-(void)viewWillDisappear:(BOOL)animated
{
    NSLog(@"%s",__FUNCTION__);
}
//视图已经消失
-(void)viewDidDisappear:(BOOL)animated
{
    NSLog(@"%s",__FUNCTION__);
}


//内存警告里什么都不要写
- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

@end