带有tableview和搜索功能的iOS App

Question

我正在编写一个 iOS 应用程序（来自 iOS 教程的更新应用程序）。它有一个带有 UITableView 和 UISearchBar 的视图（感谢 Ayan 和 Tommy）。我现在的问题是，该表显示来自核心数据实体的所有记录，当我点击一个单元格时，该应用程序会显示来自所选单元格的详细视图。这很好用。问题是使用搜索方法后，如果我点击搜索结果单元格，应用程序不会显示所选单元格的详细视图。我想我必须在任何地方确定搜索记录的发件人，但不知道如何或在哪里包括这个。 这是我目前的代码，欢迎任何帮助或提示...谢谢

#import "PersonsTVC.h"
#import "Person.h"

@implementation PersonsTVC
@synthesize fetchedResultsController = __fetchedResultsController;
@synthesize managedObjectContext = __managedObjectContext;
@synthesize selectedPerson;
@synthesize searchResults;

- (void)setupFetchedResultsController
{

    NSString *entityName = @"Person";
    NSLog(@"Setting up a Fetched Results Controller for the Entity named %@", entityName);


    NSFetchRequest *request = [NSFetchRequest fetchRequestWithEntityName:entityName];

    request.sortDescriptors = [NSArray arrayWithObject:[NSSortDescriptor sortDescriptorWithKey:@"firstname"
                                                                                     ascending:YES
                                                                                      selector:@selector(localizedCaseInsensitiveCompare:)]];

    self.fetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:request
                                                                        managedObjectContext:self.managedObjectContext
                                                                          sectionNameKeyPath:nil
                                                                                   cacheName:nil];
    [self performFetch];
}



- (void) viewDidLoad
{
    self.searchResults = [NSMutableArray arrayWithCapacity:[[self.fetchedResultsController fetchedObjects] count]];
    [self.tableView reloadData];
}
-(void) viewDidUnload{
    self.searchResults = nil;
}



- (void)viewWillAppear:(BOOL)animated
{
    [super viewWillAppear:animated];
    [self setupFetchedResultsController];
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *CellIdentifier = @"Persons Cell";

    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
    if (cell == nil) {
        cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
    }

    // Configure the cell...
    // Configure the cell...
    Person  *person = nil;

    if (tableView == self.searchDisplayController.searchResultsTableView)
    {
        NSLog(@"Configuring cell to show search results");
        person = [self.searchResults objectAtIndex:indexPath.row];
    }
    else
    {
        NSLog(@"Configuring cell to show normal data");
        person = [self.fetchedResultsController objectAtIndexPath:indexPath];
    }








    NSString *fullname = [NSString stringWithFormat:@"%@ %@", person.firstname, person.surname];
    cell.textLabel.text = person.firstname;
    if ([person.inRole.color isEqual :@"Yellow"])
    {
        cell.imageView.image = [UIImage imageNamed:@"Yellow"];
    }
    if ([person.inRole.color isEqual :@"Black"])
    {
        cell.imageView.image = [UIImage imageNamed:@"Black"];
    }
    if ([person.inRole.color isEqual :@"Grey"])
    {
        cell.imageView.image = [UIImage imageNamed:@"Grey"];
    }
    if ([person.inRole.color isEqual :@"Red"])
    {
        cell.imageView.image = [UIImage imageNamed:@"Red"];
    }
    if ([person.inRole.color isEqual :@"Blue"])
    {
        cell.imageView.image = [UIImage imageNamed:@"Blue"];
    }
    if ([person.inRole.color isEqual :@"Dark Green"])
    {
        cell.imageView.image = [UIImage imageNamed:@"DarkGreen"];
    }
    if ([person.inRole.color isEqual :@"Light Green"])
    {
        cell.imageView.image = [UIImage imageNamed:@"LightGreen"];
    }
    if ([person.inRole.color isEqual :@"Light Blue"])
    {
        cell.imageView.image = [UIImage imageNamed:@"LightBlue"];
    }
    if ([person.inRole.color isEqual :@"Brown"])
    {
        cell.imageView.image = [UIImage imageNamed:@"Brown"];
    }
    if ([person.inRole.color isEqual :@"Dark Orange"])
    {
        cell.imageView.image = [UIImage imageNamed:@"DarkOrange"];
    }
    cell.detailTextLabel.text = person.surname;
    //cell.textLabel.text = person.firstname;
    return cell;
}


- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    if (tableView == self.searchDisplayController.searchResultsTableView)
    {
        return [self.searchResults count];
    }
    else
    {
        return [[[self.fetchedResultsController sections] objectAtIndex:section] numberOfObjects];
    }
}


- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath {

    if (editingStyle == UITableViewCellEditingStyleDelete) {

        [self.tableView beginUpdates]; // Avoid  NSInternalInconsistencyException

        // Delete the person object that was swiped
        Person *personToDelete = [self.fetchedResultsController objectAtIndexPath:indexPath];
        NSLog(@"Deleting (%@)", personToDelete.firstname);
        [self.managedObjectContext deleteObject:personToDelete];
        [self.managedObjectContext save:nil];

        // Delete the (now empty) row on the table
        [self.tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
        [self performFetch];

        [self.tableView endUpdates];
    }
}

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
    if ([segue.identifier isEqualToString:@"Add Person Segue"])
    {
        NSLog(@"Setting PersonsTVC as a delegate of PersonDetailTVC");
        PersonDetailTVC *personDetailTVC = segue.destinationViewController;
        personDetailTVC.delegate = self;

        NSLog(@"Creating a new person and passing it to PersonDetailTVC");
        Person *newPerson = [NSEntityDescription insertNewObjectForEntityForName:@"Person"
                                                          inManagedObjectContext:self.managedObjectContext];

        personDetailTVC.person = newPerson; 
    }
    else if ([segue.identifier isEqualToString:@"Person Detail Segue"])
    {
        NSLog(@"Setting PersonsTVC as a delegate of PersonDetailTVC");
        PersonDetailTVC *personDetailTVC = segue.destinationViewController;
        personDetailTVC.delegate = self;

        // Store selected Person in selectedPerson property
        NSIndexPath *indexPath = [self.tableView indexPathForSelectedRow];
        self.selectedPerson = [self.fetchedResultsController objectAtIndexPath:indexPath];

        NSLog(@"Passing selected person (%@) to PersonDetailTVC", self.selectedPerson.firstname);
        personDetailTVC.person = self.selectedPerson;
    }
    else {
        NSLog(@"Unidentified Segue Attempted!");
    }
}

- (void)theSaveButtonOnThePersonDetailTVCWasTapped:(PersonDetailTVC *)controller
{
    // do something here like refreshing the table or whatever

    // close the delegated view
    [controller.navigationController popViewControllerAnimated:YES];    
}

#pragma mark -
#pragma mark Content Filtering

-(void)filterContentForSearchText:(NSString*)searchText scope:(NSString*)scope {
    self.searchResults = [[self.fetchedResultsController fetchedObjects] filteredArrayUsingPredicate:[NSPredicate predicateWithBlock:^BOOL(id evaluatedObject, NSDictionary *bindings) {
        Person* person = evaluatedObject;
        NSString* firstName = person.firstname;

        //searchText having length < 3 should not be considered
        if (!!searchText && [searchText length] < 3) {
            return YES;
        }

        if ([scope isEqualToString:@"All"] || [firstName isEqualToString:scope])  {
            return ([firstName rangeOfString:searchText].location != NSNotFound);
        }
        return NO; //if nothing matches
    }]];
}

#pragma mark -
#pragma mark UISearchDisplayController Delegate Methods

- (BOOL)searchDisplayController:(UISearchDisplayController *)controller shouldReloadTableForSearchString:(NSString *)searchString
{
    [self filterContentForSearchText:searchString scope:@"All"];
    return YES;
}

- (BOOL)searchDisplayController:(UISearchDisplayController *)controller shouldReloadTableForSearchScope:(NSInteger)searchOption
{
    [self filterContentForSearchText:[self.searchDisplayController.searchBar text] scope:@"All"];
    return YES;
}



@end

Answer 1

我猜您的故事板中有一个 segue 设置（您可以在其中按住 Control 单击从表格单元格拖动到详细视图控制器），允许触摸常规表格视图单元格以转到详细信息视图，但是您的搜索表格视图单元格没有明确说明触摸时的操作。

尝试添加表格视图委托方法 didSelectRowAtIndexPath 并在触摸搜索表格单元格时启动 segue：

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{

    // Perform segue to detail when a SEARCH table cell is touched
    if(tableView == self.searchDisplayController.searchResultsTableView)
    {
        [self performSegueWithIdentifier:@"Person Detail Segue" sender:tableView];
    }

}

这样做应该会在触摸搜索结果表格单元格时触发您的 prepareForSegue 方法。看来您已经实现了处理“Person Detail Segue”的逻辑，但我们需要添加逻辑来区分 segue 是来自选定的常规表格单元格还是来自搜索表格单元格。

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
    if ([segue.identifier isEqualToString:@"Add Person Segue"])
    {
        NSLog(@"Setting PersonsTVC as a delegate of PersonDetailTVC");
        PersonDetailTVC *personDetailTVC = segue.destinationViewController;
        personDetailTVC.delegate = self;

        NSLog(@"Creating a new person and passing it to PersonDetailTVC");
        Person *newPerson = [NSEntityDescription insertNewObjectForEntityForName:@"Person"
                                                        inManagedObjectContext:self.managedObjectContext];

        personDetailTVC.person = newPerson; 
    }
    else if ([segue.identifier isEqualToString:@"Person Detail Segue"])
    {
        NSLog(@"Setting PersonsTVC as a delegate of PersonDetailTVC");
        PersonDetailTVC *personDetailTVC = segue.destinationViewController;
        personDetailTVC.delegate = self;

        // Store selected Person in selectedPerson property
        if(sender == self.searchDisplayController.searchResultsTableView)
        {
            NSIndexPath *indexPath = [self.searchDisplayController.searchResultsTableView indexPathForSelectedRow];
            self.selectedPerson = [self.searchResults objectAtIndex:[indexPath row]];
        }
        else
        {
            NSIndexPath *indexPath = [self.tableView indexPathForSelectedRow];
            self.selectedPerson = [self.fetchedResultsController objectAtIndexPath:indexPath];
        }

        NSLog(@"Passing selected person (%@) to PersonDetailTVC",    self.selectedPerson.firstname);
        personDetailTVC.person = self.selectedPerson;
    }
    else
    {
        NSLog(@"Unidentified Segue Attempted!");
    }
}

我可能存在一些实施错误，但我相信这是对您有用的一般策略。我希望这会有所帮助。