如何正确呈现来自 Core Spotlight 和 NSUserActivity 的数据

Question

我正在尝试使用 Spotlight 结果将用户引导至我的应用中的相应部分。

这是我的结构，希望它能很好地说明它。

Navigation Controller
|
|-- Main View
    |-- About View
    |
    |-- SplitView Controller (Presented Modally;StoryboardID: PhoneDirectory)
        |-- Master View Controller
        |-- Detail View Controller
    |--Another View

当搜索结果第一次将用户带到我的应用时，一切正常。我可以展示SplitViewController，然后将用户发送到相应的DetailView。

但是，如果用户在当前状态下离开应用并返回搜索并点击另一个结果，则用户将返回应用并加载上一个视图。

我现在不知道该怎么做。

• 我是否pop 上一个视图？如果有，怎么做？
• 是否在详细视图中重新加载数据？如果有，怎么做？
• 我如何确定我已经呈现了一个需要用不同数据呈现的视图？

使用下面的代码，我在第二次搜索结果选择中收到以下警告：

Warning: Attempt to present <PhoneDirectorySplitViewController: 0x7fdf398ab600> on <UINavigationController: 0x7fdf3c831600> whose view is not in the window hierarchy!

这是我到目前为止的代码（精简）

AppDelegate.m

- (BOOL)application:(UIApplication *)application continueUserActivity:(NSUserActivity *)userActivity restorationHandler:(void (^)(NSArray * _Nullable))restorationHandler {
    NSString *uid = nil;
    if ([[userActivity activityType] isEqualToString:CSSearchableItemActionType] || [[userActivity activityType] isEqualToString:@"com.myapp.activity"]) {
        uid = [userActivity userInfo][CSSearchableItemActivityIdentifier];
    }

    if (uid != nil) {
        NSNumberFormatter *f = [[NSNumberFormatter alloc] init];
        f.numberStyle = NSNumberFormatterDecimalStyle;
        NSNumber *idNum = [f numberFromString:uid];

        UIStoryboard *storyboard = [UIStoryboard storyboardWithName:@"Main" bundle:nil];
        UINavigationController *navController = nil;
        navController = [storyboard instantiateViewControllerWithIdentifier:@"PhoneDirectory"];

        if (navController != nil) {
            [[[self window] rootViewController] presentViewController:navController animated:YES completion:nil];
            PhoneDirectoryMasterViewController *master = [[[[navController viewControllers] firstObject] childViewControllers] firstObject];
            [master selectRowWithId:idNum];

            return YES;
        }
    }

    return NO;
}

MasterView.h

- (void)selectRowWithId:(NSNumber *)uid {
    [[self displayedPersons] enumerateKeysAndObjectsUsingBlock:^(id  _Nonnull key, id  _Nonnull obj, BOOL * _Nonnull stop) {
        NSPredicate *predicate = [NSPredicate predicateWithFormat:@"(id == %@)", uid];
        NSArray *filteredPersonsArray = [obj filteredArrayUsingPredicate:predicate];
        if ([filteredPersonsArray count] > 0) {
            NSIndexPath *targetIndexPath = [NSIndexPath indexPathForRow:[[[self displayedPersons] objectForKey:key] indexOfObject:filteredPersonsArray[0]] inSection:[[self personIndexTitles] indexOfObject:key]];

            [[self tableView] selectRowAtIndexPath:targetIndexPath animated:NO scrollPosition:UITableViewScrollPositionMiddle];
            [self performSegueWithIdentifier:@"showPhoneDirectoryDetail" sender:self];
        }
    }];
}

如果您需要更多信息，请告诉我。

Answer 1

您需要在适当的地方进行一些验证检查。将此声明添加到您的 AppDelegate.m

UISplitViewController *splitViewController;

您可能需要保留对splitViewController 的引用，因为您需要第二次访问它，并且您不能在每次需要时都创建新的控制器实例。目前，每次从外部返回应用程序时，您都会创建一个新的 splitViewController 实例。

检查 #1

if(splitViewController == nil)
{
    // Only create a new splitViewController if it's not have been created already
    splitViewController = [storyboard instantiateViewControllerWithIdentifier:@"PhoneDirectory"];
}

检查 #2

// presentingViewController points to the base viewController that presented it
    if(splitViewController.presentingViewController == nil)
    {
        // Only present splitViewController is it's not been presented already
        [[[self window] rootViewController] presentViewController:splitViewController animated:YES completion:nil];
    }

检查 #3（在您的 MasterViewController.m 'selectRowWithId:' 内）

// Finally before making the push with new instance, just pop the old one out of the navigationStack
    [self.navigationController popViewControllerAnimated:YES];

    [self performSegueWithIdentifier:@"showPhoneDirectoryDetail" sender:self];

这就是你所需要的。希望这会有所帮助。

Answer 2

因此，在查看了许多 SO 问题/答案之后，这就是我想出的。它可能不是普遍的，但它有效。如果有人可以使其通用，请随时提交新答案。

AppDelegate.m

- (BOOL)application:(UIApplication *)application continueUserActivity:(NSUserActivity *)userActivity restorationHandler:(void (^)(NSArray * _Nullable))restorationHandler {
    NSString *uid = nil;
    if ([[userActivity activityType] isEqualToString:CSSearchableItemActionType] || [[userActivity activityType] isEqualToString:@"com.myapp.activity"]) {
        uid = [userActivity userInfo][CSSearchableItemActivityIdentifier];
    }

    if (uid != nil) {
        NSNumberFormatter *f = [[NSNumberFormatter alloc] init];
        f.numberStyle = NSNumberFormatterDecimalStyle;
        NSNumber *idNum = [f numberFromString:uid];

        UIViewController *vc = [[[[UIApplication sharedApplication] keyWindow] rootViewController] presentedViewController];

        if ([vc class] == [PhoneDirectorySplitViewController class]) {
            if ([vc respondsToSelector:@selector(dismissViewControllerAnimated:completion:)]) {
                [vc dismissViewControllerAnimated:NO completion:^{
                    [self showUserActivity:idNum];
                }];
            }
        } else if ([vc class] == [UINavigationController class]) {
            if ([vc respondsToSelector:@selector(visibleViewController)]) {
                if ([[(UINavigationController *)vc visibleViewController] respondsToSelector:@selector(dismissViewControllerAnimated:completion:)]) {
                    [[(UINavigationController *)vc visibleViewController] dismissViewControllerAnimated:NO completion:^{
                        [self showUserActivity:idNum];
                    }];
                }
            }
        } else {
            [self showUserActivity:idNum];
        }

        return YES;
    }

    return NO;
}

- (void)showUserActivity:(NSNumber *)idNum {
    UIStoryboard *storyboard = [UIStoryboard storyboardWithName:@"Main" bundle:nil];
    UINavigationController *navController = nil;
    navController = [storyboard instantiateViewControllerWithIdentifier:@"PhoneDirectory"];

    if (navController != nil) {
        [[[self window] rootViewController] presentViewController:navController animated:YES completion:nil];
        PhoneDirectoryMasterViewController *master = [[[[navController viewControllers] firstObject] childViewControllers] firstObject];
        [master selectRowWithId:idNum];
    }
}