从UITableViewCell 3D Touch Peek和Pop如何将数据移交给其他UIViewController？

Question

我的应用程序在Core Data对象中存储不同的属性.它们都显示在UITableView中,如果单击一个单元格,则会显示DetailView.通常的东西,如Master-Detail-XCode-Template.

现在我想用peek和pop实现3D Touch.就像在Mail应用程序中一样,3D触摸一个单元格,进行预览,按下更深处,弹出细节.

到目前为止,我已经完成了这项工作,但我无法弄清楚如何传递相应的数据

- (nullable UIViewController *)previewingContext:(id <UIViewControllerPreviewing>)previewingContext viewControllerForLocation:(CGPoint)location

和

- (void)previewingContext:(id <UIViewControllerPreviewing>)previewingContext commitViewController:(UIViewController *)viewControllerToCommit

到另一个DetailViewController.

如果您只是单击单元格(无3D触摸),我会将数据移交给

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {

    NSIndexPath *indexPath = [self.tableView indexPathForSelectedRow];
    NSManagedObject *object = [[self fetchedResultsController] objectAtIndexPath:indexPath];
    [[segue destinationViewController] setDetailItem:object];

我正在使用

id detailItem

在每个ViewController中我都设置了相应的对象.

所以我尝试得到类似的东西,所以在我的DetailViewController中,我的"detailItem"需要来自所选(3D触摸)单元格的相应Core Data对象.

感谢帮助 !

Answer 1

如果您使用从单元格到新视图控制器的故事板segue,则发件人是表格视图单元格.

所以你可以这样实现prepareForSegue::

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {

    if ([sender isKindOfClass:[UITableViewCell class]]) {

        UITableViewCell *cell = sender;
        NSIndexPath *indexPath = [self.tableView indexPathForCell:cell];

        id viewController = segue.destinationViewController;

        // Get your data object
        // Pass it to the new view controller
    }
}

Answer 2

使用故事板ID从故事板中获取目标View控制器,并传递您在prepareForSegue方法中执行的对象.

下面是我用来传递数据的代码.它在Swift中,它应该在目标C中类似.如果你想要Objective C版本,请告诉我.

func previewingContext(previewingContext: UIViewControllerPreviewing,viewControllerForLocation location: CGPoint) -> UIViewController? method:

    // Obtain the index path and the cell that was pressed.
    guard let indexPath = tableView.indexPathForRowAtPoint(location),
              cell = tableView.cellForRowAtIndexPath(indexPath) else { return nil }

    // Create a destination view controller and set its properties.
    guard let destinationViewController = storyboard?.instantiateViewControllerWithIdentifier("DestinationViewController") as? DestinationViewController else { return nil }
    let object = fetchedResultController.objectAtIndexPath(indexPath)
    destinationViewController.detailItem = object

    /*
        Set the height of the preview by setting the preferred content size of the destination view controller. Height: 0.0 to get default height
    */
    destinationViewController.preferredContentSize = CGSize(width: 0.0, height: 0.0)

    previewingContext.sourceRect = cell.frame

    return destinationViewController
}