iOS 开发笔记-控制器tab切换view显示

//
//  ViewController.m
//  控制器tab切换view显示
//
//  Created by jiangys on 15/10/11.
//  Copyright © 2015年 Jiangys. All rights reserved.
//

#import "ViewController.h"

#import "OneViewController.h"
#import "TwoViewController.h"
#import "ThreeViewController.h"

@interface ViewController ()
- (IBAction)vc1;
- (IBAction)vc2;
- (IBAction)vc3;


/** one */
@property (nonatomic, strong) OneViewController *one;
/** two */
@property (nonatomic, strong) TwoViewController *two;
/** three */
@property (nonatomic, strong) ThreeViewController *three;

@end

@implementation ViewController

- (OneViewController *)one
{
    if (!_one) {
        self.one = [[OneViewController alloc] init];
        self.one.view.frame = CGRectMake(10, 70, 300, 300);
    }
    return _one;
}

- (TwoViewController *)two
{
    if (!_two) {
        self.two = [[TwoViewController alloc] init];
        self.two.view.frame = CGRectMake(10, 70, 300, 300);
    }
    return _two;
}

- (ThreeViewController *)three
{
    if (!_three) {
        self.three = [[ThreeViewController alloc] init];
        self.three.view.frame = CGRectMake(10, 70, 300, 300);
    }
    return _three;
}


- (void)viewDidLoad {
    [super viewDidLoad];
    //    HestViewController *test = [[TestViewController alloc] init];
    //    test.view.frame = CGRectMake(100, 100, 200, 300);
    //    test.view.backgroundColor = [UIColor redColor];
    //    [self.view addSubview:test.view];
    //    self.test = test;
    
    // 如果发现：控制器的view还在，但是view上面的数据不显示，极大可能是因为：控制器被提前销毁了
    
    // 1.一个控制器的view是可以随意调整尺寸和位置的
    // 2.一个控制器的view是可以随意添加到其他view中
    // 3.如果将一个控制器的view，添加到其他view中显示，那么要想办法保证控制器不被销毁
    // 4.原则：只要view在，view所在的控制器必须得在，这样才能保证view内部的数据和业务逻辑正常
}

- (IBAction)vc1 {
    [self.two.view removeFromSuperview];
    [self.three.view removeFromSuperview];
    [self.view addSubview:self.one.view];
}

- (IBAction)vc2 {
    [self.one.view removeFromSuperview];
    [self.three.view removeFromSuperview];
    [self.view addSubview:self.two.view];
}

- (IBAction)vc3 {
    [self.two.view removeFromSuperview];
    [self.one.view removeFromSuperview];
    [self.view addSubview:self.three.view];
}
@end