动态更新UIPageViewController内容

Question

我正在寻找一种在UIPageViewController中动态显示内容的解决方案。

我的应用正在寻找蓝牙设备，我将它们显示为我的UIPageViewController的不同页面。用户可以使用所有这些设备执行一些操作。

我的目标是每次我的应用发现新设备时添加新页面（如果设备不再可用，则删除页面）。

我的AppDelegate在连接/断开设备时收到通知。

有可能吗？ 有没有正确的方法呢？我正在考虑从我的AppDelegate调用UIPageViewController上的更新方法，并添加/删除包含所有视图的数组中的视图。谢谢你的帮助！

以下是我的DevicesPageViewController示例，作为我的UIPageViewController的DataSource AND Delegate（请注意，我只给出了我修改过的方法）：

这是.h

@interface DevicesPageViewController : UIViewController <UIPageViewControllerDataSource, UIPageViewControllerDelegate>

// Devices items, used for loading the data in
@property (nonatomic, strong) NSMutableArray *devices;

// All children view controllers : all the pages of my UIPageController
@property (nonatomic, strong) NSMutableArray *childrenViewControllers;

@property (nonatomic, strong) UIPageViewController *pageViewController;

- (void) buildDataModelFromDevices;
- (void) updateView;

@end

这是.m：

@implementation DevicesPageViewController

- (id) init {
self = [super init];

// Init the pageViewController - This is the UIPageViewController
UIStoryboard*  sb = [UIStoryboard storyboardWithName:@"iphoneSTORYBOARD" bundle:nil];
self.pageViewController = [sb instantiateViewControllerWithIdentifier:@"pageViewController"];
self.pageViewController.dataSource = self;
self.pageViewController.delegate = self;

// Move the pageViewController where it belong
[self addChildViewController:self.pageViewController];
[self.view addSubview:self.pageViewController.view];
[self.pageViewController didMoveToParentViewController:self];

// AT_appDelegate is a macro, getting the AppDelegate
if (AT_appDelegate.userDevices.count > 0) {
    [self updateView];
}

return self;
}

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil {
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
return self;
}

#pragma mark - PageController DataSource

/**
 *  View controller to give before
 */
- (UIViewController*) pageViewController:(UIPageViewController *)pageViewController     viewControllerBeforeViewController:(UIViewController *)viewController {

NSUInteger index = ((DeviceContentViewController*) viewController).pageIndex;

if ((index == 0) || (index == NSNotFound)) { return nil; }
index--;

return [self.childrenViewControllers objectAtIndex:index];
}

/**
 *  View controller to give after
 */
- (UIViewController*) pageViewController:(UIPageViewController *)pageViewController viewControllerAfterViewController:(UIViewController *)viewController {

NSUInteger index = ((DeviceContentViewController*) viewController).pageIndex;

if ((index == [self.childrenViewControllers count]) || (index == NSNotFound)) { return nil; }
index++;

return [self.childrenViewControllers objectAtIndex:index];
}

/**
 *  Build data model and init all children view controllers
 */
- (void) buildDataModelFromDevices {

int index = 0;
// For each device to load, create a viewController
for (Device *d in self.devices) {
    // Instantiate corresponding view controller
    DeviceContentViewController *deviceVC = [[UIStoryboard storyboardWithName:@"iphoneSTORYBOARD" bundle:nil] instantiateViewControllerWithIdentifier:@"deviceContentVC"];

    // Load the device in it
    deviceVC.device = d;
    deviceVC.pageIndex = index;
    [deviceVC loadData];

    index++;
    [self.childrenViewControllers addObject:deviceVC];
}
}

- (void) updateView {
NSLog(@"[ DevicesPageViewController ] -- Updating view from devices...");

// Build the data
self.devices = [[NSMutableArray alloc] initWithArray:AT_appDelegate.userDevices];
[self buildDataModelFromDevices];

if (self.childrenViewControllers.count > 0) {
    // Get the first view controller
    NSArray *tmp_viewControllers = @[[self.childrenViewControllers objectAtIndex:0]];
    [self.pageViewController setViewControllers:tmp_viewControllers direction:UIPageViewControllerNavigationDirectionForward animated:true completion:nil];
}
}

@end