IOS開發—通過ChildViewController實現view的切換

標籤：ios開發   childviewcontroller   parentviewcontroller   視圖切換   

ChildViewController的應用

viewControlle中可以添加多個subView，在需要的時候顯示出來；另一種方法是通過向parentViewController中可以添加多個childCiewController;來控制頁面中的subView，降低代碼耦合度；通過切換子視圖控制器，可以顯示不同的view；，替代之前的addSubView的管理。

本節通過類似百度新聞模組切換的介面來示範ChileViewController的應用：

文檔結構：

代碼示範：

#import "MainViewController.h"#import "FirstViewController.h"#import "SecondViewController.h"#import "ThirdViewController.h"@interface MainViewController ()@property (nonatomic, strong) FirstViewController *firstVC;@property (nonatomic, strong) SecondViewController *secondVC;@property (nonatomic, strong) ThirdViewController *thirdVC;@property (nonatomic, strong) UIViewController *currentVC; @property (nonatomic, strong) UIScrollView *headScrollView;@property (nonatomic, strong) NSMutableArray *itemArray;@property (nonatomic, strong) UIView *contentView;@end @implementation MainViewController- (void)loadView{    [super loadView];    [self initialization];} - (void)viewDidLoad {    [super viewDidLoad];    [self loadBaseUI];} - (void)initialization{    _itemArray = [NSMutableArray arrayWithObjects:@"頭條",@"今日",@"焦點", nil];} - (void)loadBaseUI{    self.title = @"首頁";    _headScrollView = [[UIScrollView alloc]initWithFrame:CGRectMake(0, 0, [UIScreen mainScreen].bounds.size.width, 44)];    _headScrollView.backgroundColor = [UIColor colorWithWhite:0.902 alpha:1.000];    for (int i = 0; i<_itemArray.count; i++) {        UIButton *itemButton = [[UIButton alloc]initWithFrame:CGRectMake(i*([UIScreen mainScreen].bounds.size.width/_itemArray.count), 0, [UIScreen mainScreen].bounds.size.width/_itemArray.count, 44)];        itemButton.tag = 100+i;        itemButton.backgroundColor = [UIColor clearColor];        NSDictionary *dic = @{NSForegroundColorAttributeName:[UIColor purpleColor],NSFontAttributeName:[UIFont systemFontOfSize:14.0f]};        [itemButton setAttributedTitle:[[NSAttributedString alloc]initWithString:_itemArray[i] attributes:dic] forState:UIControlStateNormal];        [itemButton addTarget:self action:@selector(buttonClick:) forControlEvents:UIControlEventTouchUpInside];        [_headScrollView addSubview:itemButton];    }    [_headScrollView setContentSize:CGSizeMake([UIScreen mainScreen].bounds.size.width, 44)];    _headScrollView.showsHorizontalScrollIndicator = NO;    _headScrollView.showsVerticalScrollIndicator = NO;    [self.view addSubview:_headScrollView];       _contentView = [[UIView alloc]initWithFrame:CGRectMake(0, 44, [UIScreen mainScreen].bounds.size.width, [UIScreen mainScreen].bounds.size.height - 44 - 64)];    _contentView.backgroundColor = [UIColor clearColor];    [self.view addSubview:_contentView];       [self addSubControllers];} #pragma mark - privatemethods- (void)addSubControllers{    _firstVC = [[FirstViewController alloc]initWithNibName:@"FirstViewController" bundle:nil];    [self addChildViewController:_firstVC];       _secondVC = [[SecondViewController alloc]initWithNibName:@"SecondViewController" bundle:nil];    [self addChildViewController:_secondVC];       _thirdVC = [[ThirdViewController alloc]initWithNibName:@"ThirdViewController" bundle:nil];    [self addChildViewController:_thirdVC];     //調整子視圖控制器的Frame已適應容器View    [self fitFrameForChildViewController:_firstVC];    //設定預設顯示在容器View的內容    [self.contentView addSubview:_firstVC.view];       NSLog(@"%@",NSStringFromCGRect(self.contentView.frame));    NSLog(@"%@",NSStringFromCGRect(_firstVC.view.frame));       _currentVC = _firstVC;} - (void)buttonClick:(UIButton *)sender{    if ((sender.tag == 100 && _currentVC == _firstVC) || (sender.tag == 101 && _currentVC == _secondVC) || (sender.tag == 102 && _currentVC == _thirdVC)) {        return;    }    switch (sender.tag) {        case 100:{            [self fitFrameForChildViewController:_firstVC];            [self transitionFromOldViewController:_currentVC toNewViewController:_firstVC];        }            break;        case 101:{            [self fitFrameForChildViewController:_secondVC];            [self transitionFromOldViewController:_currentVC toNewViewController:_secondVC];        }            break;        case 102:{            [self fitFrameForChildViewController:_thirdVC];            [self transitionFromOldViewController:_currentVC toNewViewController:_thirdVC];        }            break;    }} - (void)fitFrameForChildViewController:(UIViewController *)chileViewController{    CGRect frame = self.contentView.frame;    frame.origin.y = 0;    chileViewController.view.frame = frame;} //轉換子視圖控制器- (void)transitionFromOldViewController:(UIViewController *)oldViewControllertoNewViewController:(UIViewController *)newViewController{    [self transitionFromViewController:oldViewController toViewController:newViewController duration:0.3 options:UIViewAnimationOptionTransitionCrossDissolve animations:nil completion:^(BOOL finished) {        if (finished) {            [newViewController didMoveToParentViewController:self];            _currentVC = newViewController;        }else{            _currentVC = oldViewController;        }    }];} //移除所有子視圖控制器- (void)removeAllChildViewControllers{    for (UIViewController *vc in self.childViewControllers) {        [vc willMoveToParentViewController:nil];        [vc removeFromParentViewController];    }} /** *  方法說明： *  1、addChildViewController:向父VC中添加子VC，添加之後自動調用willMoveToParentViewController:父VC *  2、removeFromParentViewController:將子VC從父VC中移除，移除之後自動調用    didMoveToParentViewController:nil *  3、willMoveToParentViewController:  當向父VC添加子VC之後，該方法會自動調用。若要從父VC移除子VC，需要在移除之前調用該方法，傳入參數nil。 *  4、didMoveToParentViewController:  當向父VC添加子VC之後，該方法不會被自動調用，需要顯示調用告訴編譯器已經完成添加（事實上不調用該方法也不會有問題，不太明白）; 從父VC移除子VC之後，該方法會自動調用，傳入的參數為nil,所以不需要顯示調用。 */ /** *  注意點：    要想切換子視圖控制器a/b,a/b必須均已添加到父視圖控制器中，不然會報錯 */@end

最終效果：(實現了3個視圖之間的切換)

   

IOS開發—通過ChildViewController實現view的切換