iOS開發 剖析網易新聞標籤欄視圖切換(addChildViewController屬性介紹)

標籤：i++   current   jsb   stat   cross   科技   class   ios開發   ++   

            本來僅僅是打算介紹一下addChildViewController這種方法的,正好今天朋友去換工作面試問到網易新聞標籤欄效果的實現,就結合它,用個小Demo執行個體介紹一下:(詳細解釋都寫在了Demo裡面的凝視)

////  HMTMainViewController.m//  UIScrollView////  Created by HMT on 14-6-25.//  Copyright (c) 2014年 humingtao. All rights reserved.//#import "HMTMainViewController.h"#import "HMTFirstViewController.h"#import "HMTSecondViewController.h"#import "HMTThirdViewController.h"@interface HMTMainViewController () <UIScrollViewDelegate>@property (nonatomic ,strong) HMTThirdViewController  *thirdVC;@property (nonatomic ,strong) HMTFirstViewController  *firstVC;@property (nonatomic ,strong) HMTSecondViewController *secondVC;@property (nonatomic ,strong) UIViewController *currentVC;@property (nonatomic ,strong) UIScrollView *headScrollView;  //  頂部滾動視圖@property (nonatomic ,strong) NSArray *headArray;@end@implementation HMTMainViewController- (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.       self.navigationItem.title = @"網易新聞Demo";        self.headArray = @[@"頭條",@"娛樂",@"體育",@"財經",@"科技",@"NBA",@"手機"];    /**     *   automaticallyAdjustsScrollViewInsets   又被這個屬性坑了     *   我"UI進階"裡面一篇文章著重講了它,大家能夠去看看     */    self.automaticallyAdjustsScrollViewInsets = NO;    self.headScrollView = [[UIScrollView alloc] initWithFrame:CGRectMake(0, 64, 320, 40)];    self.headScrollView.backgroundColor = [UIColor purpleColor];    self.headScrollView.contentSize = CGSizeMake(560, 0);    self.headScrollView.bounces = NO;    self.headScrollView.pagingEnabled = YES;    [self.view addSubview:self.headScrollView];    for (int i = 0; i < [self.headArray count]; i++) {                UIButton *button = [UIButton buttonWithType:UIButtonTypeSystem];        button.frame = CGRectMake(0 + i*80, 0, 80, 40);        [button setTitle:[self.headArray objectAtIndex:i] forState:UIControlStateNormal];        button.tag = i + 100;        [button addTarget:self action:@selector(didClickHeadButtonAction:) forControlEvents:UIControlEventTouchUpInside];        [self.headScrollView addSubview:button];            }        /*     蘋果新的API添加了addChildViewController方法，而且希望我們在使用addSubview時，同一時候調用[self addChildViewController:child]方法將sub view相應的viewController也加到當前ViewController的管理中。     對於那些當前臨時不須要顯示的subview，僅僅通過addChildViewController把subViewController加進去；須要顯示時再調用transitionFromViewController方法。
將其加入進入底層的ViewController中。     這樣做的優點：          1.無疑，對頁面中的邏輯更加分明了。相應的View相應相應的ViewController。
     2.當某個子View沒有顯示時，將不會被Load，降低了記憶體的使用。     3.當記憶體緊張時，沒有Load的View將被首先釋放，最佳化了程式的記憶體釋放機制。     */        /**     *  在iOS5中。ViewController中新加入了以下幾個方法：     *  addChildViewController:     *  removeFromParentViewController     *  transitionFromViewController:toViewController:duration:options:animations:completion:     *  willMoveToParentViewController:     *  didMoveToParentViewController:     */    self.firstVC = [[HMTFirstViewController alloc] init];    [self.firstVC.view setFrame:CGRectMake(0, 104, 320, 464)];    [self addChildViewController:_firstVC];        self.secondVC = [[HMTSecondViewController alloc] init];    [self.secondVC.view setFrame:CGRectMake(0, 104, 320, 464)];        self.thirdVC = [[HMTThirdViewController alloc] init];    [self.thirdVC.view setFrame:CGRectMake(0, 104, 320, 464)];        //  預設,第一個視圖(你會發現,全程就這一個用了addSubview)    [self.view addSubview:self.firstVC.view];    self.currentVC = self.firstVC;    }- (void)didClickHeadButtonAction:(UIButton *)button{    //  點擊處於當前頁面的按鈕,直接跳出    if ((self.currentVC == self.firstVC && button.tag == 100)||(self.currentVC == self.secondVC && button.tag == 101.)) {        return;    }else{            //  展示2個,其餘一樣,自行補全噢        switch (button.tag) {            case 100:                [self replaceController:self.currentVC newController:self.firstVC];                break;            case 101:                [self replaceController:self.currentVC newController:self.secondVC];                break;            case 102:                //.......                break;            case 103:                //.......                break;            case 104:                //.......                break;            case 105:                //.......                break;            case 106:                //.......                break;                //.......            default:                break;        }    }}//  切換各個標籤內容- (void)replaceController:(UIViewController *)oldController newController:(UIViewController *)newController{    /**     *            著重介紹一下它     *  transitionFromViewController:toViewController:duration:options:animations:completion:     *  fromViewController      當前顯示在父視圖控制器中的子視圖控制器     *  toViewController        將要顯示的姿勢圖控制器     *  duration                動畫時間(這個屬性,old friend 了 O(∩_∩)O)     *  options                 動畫效果(漸層,從下往上等等,詳細查看API)     *  animations              轉換過程中得動畫     *  completion              轉換完畢     */        [self addChildViewController:newController];    [self transitionFromViewController:oldController toViewController:newController duration:2.0 options:UIViewAnimationOptionTransitionCrossDissolve animations:nil completion:^(BOOL finished) {                        if (finished) {                                [newController didMoveToParentViewController:self];            [oldController willMoveToParentViewController:nil];            [oldController removeFromParentViewController];            self.currentVC = newController;                        }else{                                self.currentVC = oldController;                        }    }];}

watermark/2/text/aHR0cDovL2Jsb2cuY3Nkbi5uZXQvaG10MjAxMzA0MTI=/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70/gravity/Center" >

iOS開發 剖析網易新聞標籤欄視圖切換(addChildViewController屬性介紹)