Apple 在其 iOS 开发网站上展示了一个示例,说明如何使用具有不同细节 View 的 Split View (see MultipleDetailViews Example)。在 RootViewController 每次选择单元格时,都会初始化一个新的 DetailViewController:
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
/*
Create and configure a new detail view controller appropriate for the selection.
*/
NSUInteger row = indexPath.row;
UIViewController <SubstitutableDetailViewController> *detailViewController = nil;
if (row == 0) {
FirstDetailViewController *newDetailViewController = [[FirstDetailViewController alloc] initWithNibName:@"FirstDetailView" bundle:nil];
detailViewController = newDetailViewController;
}
if (row == 1) {
SecondDetailViewController *newDetailViewController = [[SecondDetailViewController alloc] initWithNibName:@"SecondDetailView" bundle:nil];
detailViewController = newDetailViewController;
}
// Update the split view controller's view controllers array.
NSArray *viewControllers = [[NSArray alloc] initWithObjects:self.navigationController, detailViewController, nil];
splitViewController.viewControllers = viewControllers;
[viewControllers release];
// Dismiss the popover if it's present.
if (popoverController != nil) {
[popoverController dismissPopoverAnimated:YES];
}
// Configure the new view controller's popover button (after the view has been displayed and its toolbar/navigation bar has been created).
if (rootPopoverButtonItem != nil) {
[detailViewController showRootPopoverButtonItem:self.rootPopoverButtonItem];
}
[detailViewController release];
}
现在我的想法不是每次都初始化 View Controller ,而是在 viewDidLoad(以及 header )中初始化 Controller ,并在选择单元格时传递它们的引用:
rootviewcontroller中viewDidLoad的一部分:
firstDetailViewController = [[FirstDetailViewController alloc] initWithNibName:@"FirstDetailView" bundle:nil];
secondDetailViewController = [[FirstDetailViewController alloc] initWithNibName:@"FirstDetailView" bundle:nil];
现在 tableView 的 didselectrow 方法看起来像这样:
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
/*
Create and configure a new detail view controller appropriate for the selection.
*/
NSUInteger row = indexPath.row;
UIViewController <SubstitutableDetailViewController> *detailViewController = nil;
if (row == 0) {
detailViewController = firstDetailViewController;
}
if (row == 1) {
detailViewController = secondDetailViewController;
}
// Update the split view controller's view controllers array.
NSArray *viewControllers = [[NSArray alloc] initWithObjects:self.navigationController, detailViewController, nil];
splitViewController.viewControllers = viewControllers;
[viewControllers release];
// Dismiss the popover if it's present.
if (popoverController != nil) {
[popoverController dismissPopoverAnimated:YES];
}
// Configure the new view controller's popover button (after the view has been displayed and its toolbar/navigation bar has been created).
if (rootPopoverButtonItem != nil) {
[detailViewController showRootPopoverButtonItem:self.rootPopoverButtonItem];
}
//[detailViewController release];
}
在横向模式下一切正常,但在纵向模式下出现错误,从第一个详细 View Controller 切换到第二个,然后切换到第一个,然后想切换到第二个。出现以下消息:由于未捕获的异常“NSInvalidArgumentException”而终止应用程序,原因:“无法从没有窗口的 View 中显示弹出窗口。”
从昨天晚上开始,我一直在努力解决这个问题,但我没有找到解决方案。有人有想法吗?
干杯,多米尼克
最佳答案
我遇到了类似的问题,但我发现了这个 post这证明了在设置 splitView 的 View Controller 之前必须从先前的 detailView 中删除 leftBarButtonItem 的想法。此代码为我解决了这个问题。
这是 TPoschel 编写的代码。
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
// Retrieve the new detail view controller
UIViewController *detailViewController = [[self.allData objectAtIndex:indexPath.section] objectAtIndex:indexPath.row];
// Add the detail view controller to a navigation controller and set the bar style
UINavigationController *detailNavigationController = [[UINavigationController alloc] initWithRootViewController:detailViewController];
detailNavigationController.navigationBar.barStyle = [[NSUserDefaults standardUserDefaults] integerForKey:@"UIBarStyle"];
// Retrieve previous detail view controller and remove the leftBarButtonItem
UINavigationController *previousDetailNavigationController = [splitViewController.viewControllers objectAtIndex:1];
UIViewController *previousDetailViewController = [[previousDetailNavigationController viewControllers] lastObject];
previousDetailViewController.navigationItem.leftBarButtonItem = nil;
// Update the split view controller's view controllers array.
NSArray *viewControllers = [[NSArray alloc] initWithObjects:self.navigationController, detailNavigationController, nil];
splitViewController.viewControllers = viewControllers;
[detailNavigationController release];
[viewControllers release];
// Dismiss the popover if it's present.
if (popoverController != nil) {
[popoverController dismissPopoverAnimated:YES];
}
// This sets the left bar to nil when in landscape and equal to "Menu" when in portrait.
// We need to remove rootPopoverButtonItem from the previous viewController...
detailViewController.navigationItem.leftBarButtonItem = rootPopoverButtonItem;
}
关于ios - 在 Apples MultipleDetailViews Example 中加载已经初始化的 DetailViewControllers,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/6339991/