UISearchDisplayController.displays SearchBarOn NavigationBar 将搜索栏定位在窗口的中间

Question

我正在尝试使用 iOS7 UISearchDisplayController 类中的 displaysSearchBarInNavigationBar 属性在导航栏中显示搜索栏。

使用AdvancedTableSearch example from Apple 作为基础，我更改了代码以禁用范围（导航栏中不允许这样做）并将displaysSearchBarInNavigationBar 设置为true，就像这样。

- (void)viewDidLoad
{
   [super viewDidLoad];

   // create a mutable array to contain products for the search results table
   self.searchResults = [NSMutableArray arrayWithCapacity:[self.products count]];
   self.searchDisplayController.displaysSearchBarInNavigationBar = YES;
}

不幸的是，我得到的结果如下所示：

搜索栏出现在屏幕中间，而不是在 navigationItem 中。

我做错了什么？

PS：我不确定它是否相关，但self.searchDisplayController.navigationItem 属性是nil。

Answer 1

从表格视图中删除搜索栏。使用displaysSearchBarInNavigationBar 意味着 UISearchDisplayController 将负责为您将搜索栏放置在层次结构中。

此外，navigationItem 将为零，直到 displaysSearchBarInNavigationBar 设置为 YES。该项目仅在需要时创建。

Answer 2

我遇到了和你一样的问题，花了几个小时寻找解决方案。最终我以编程方式创建了UISearchDisplayController。

我在Storyboard 中创建了一个SearchTableViewController，然后以编程方式完成其余的工作。正如您将在下面提供的代码中注意到的那样，控制器委托必须包含在标头中。现在有趣的事情发生在我创建searchBar 时。请注意我从未设置它的委托？当我使用searchBar 创建它时，UISearchDisplayController 正在为我做这件事。然后我只需要为UISearchDislpayController 和searchResults 设置委托和源；我在创建控制器后立即执行此操作。我无法为您提供关于“为什么”的答案，当在 Storyboard 中创建并在代码中设置为 displaysSearchBarInNavigationBar:YES 时，searchBar 在视图中居中，但我遇到了同样的问题并发现以下是可行的解决方案。特别是考虑到我从来不需要调整任何东西的大小:)

SearchTableViewController.h

#import <UIKit/UIKit.h>

@interface SearchableTableViewController : UITableViewController<UISearchDisplayDelegate>
//I only need the SearchDisplayController Delegate because it magically has all the needed child delegates. :)
@end

SearchTableViewController.m

#import "SearchDisplayController.h"

@property (strong,nonatomic)  IBOutlet UITableView *acSearchTableView;
@property (retain,nonatomic)  UISearchBar *acSearchBar;
@property (retain,nonatomic)  UISearchDisplayController *searchDsplyCntrl;
@property (strong,nonatomic)  NSArray *unfilteredResults;
@property (strong,nonatomic)  NSMutableArray *filteredResults;

@implementation SearchTableViewController 

- (void) viewDidLoad {
    [super viewDidLoad];

    _acSearchBar = [[UISearchBar alloc]init];
    _acSearchBar.showsCancelButton = NO;

    /* NOTE: by default the placholer is centered. It can be left aligned with spaces */
    _acSearchBar.placeholder = @"Search                                                      ";

    _searchDsplyCntrl = [[UISearchDisplayController alloc]initWithSearchBar:_acSearchBar contentsController:self];
    _searchDsplyCntrl.delegate = self;
    _searchDsplyCntrl.searchResultsDelegate = self;
    _searchDsplyCntrl.searchResultsDataSource = self;
    _searchDsplyCntrl.displaysSearchBarInNavigationBar = YES;

    _unfilteredResults = [[NSArray alloc]initWithObjects:
                                               [ResultObj resultWithName:@"first"],
                                               [ResultObj resultWithName:@"second"],
                                               [ResultObj resultWithName:@"third"],
                                               [ResultObj resultWithName:@"forth"],
                                               [ResultObj resultWithName:@"fifth"],
                                               [ResultObj resultWithName:@"sixth"],
                                               [ResultObj resultWithName:@"seventh"],
                                               [ResultObj resultWithName:@"eigth"],nil];

    _filteredResults = [NSMutableArray arrayWithCapacity:[_unfilteredResults count]];

    [_acSearchTableView reloadData];
}

- (void)searchDisplayControllerWillBeginSearch:(UISearchDisplayController *)controller {
    [_searchDsplyCntrl setActive:YES animated:YES];
    [_searchDsplyCntrl.searchBar setShowsCancelButton:YES animated:YES];
}
- (void)searchDisplayControllerWillEndSearch:(UISearchDisplayController *)controller {
    [_searchDsplyCntrl setActive:NO animated:YES];
    [_searchDsplyCntrl.searchBar setShowsCancelButton:NO animated:YES];
}

A search bar displayed in a navigation bar cannot have a scope bar.

重要提示如果您设置了 showsScopeBar，系统会引发异常 在导航栏中显示的搜索栏中将属性设置为 YES。

#pragma mark - Table view data source

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
    return 1;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
    if (tableView == _searchDsplyCntrl.searchResultsTableView)
    {
        return [_filteredResults count];
    }
    else
    {
        return [_unfilteredResults count];
    }
}


- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{

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

    // Create a new Candy Object
    ResultObj *result = nil;

    // Check to see whether the normal table or search results table is being displayed and set the Candy object from the appropriate array
    if (tableView == _searchDsplyCntrl.searchResultsTableView)
    {
        result = [_filteredResults objectAtIndex:[indexPath row]];
    }
    else
    {
        result = [_unfilteredResults objectAtIndex:[indexPath row]];
    }

    // Configure the cell
    [[cell textLabel] setText:[result name]];
    [cell setAccessoryType:UITableViewCellAccessoryDisclosureIndicator];

    return cell;
}

#pragma mark Content Filtering

- (void)filterContentForSearchText:(NSString*)searchText scope:(NSString*)scope
{
    // Update the filtered array based on the search text and scope.

    // Remove all objects from the filtered search array
    [_filteredResults removeAllObjects];

    // Filter the array using NSPredicate
    NSPredicate *predicate = [NSPredicate predicateWithFormat:@"SELF.name contains[c] %@",searchText];
    NSArray *tempArray = [_unfilteredResults filteredArrayUsingPredicate:predicate];


    /*
    if(![scope isEqualToString:@"All"]) {
        // Further filter the array with the scope
        NSPredicate *scopePredicate = [NSPredicate predicateWithFormat:@"SELF.category contains[c] %@",scope];
        tempArray = [tempArray filteredArrayUsingPredicate:scopePredicate];
    }
    */

    _filteredResults = [NSMutableArray arrayWithArray:tempArray];
}

#pragma mark - UISearchDisplayController Delegate Methods

- (BOOL)searchDisplayController:(UISearchDisplayController *)controller shouldReloadTableForSearchString:(NSString *)searchString
{
    // Tells the table data source to reload when text changes
    [self filterContentForSearchText:searchString scope:
     [[_searchDsplyCntrl.searchBar scopeButtonTitles] objectAtIndex:[_searchDsplyCntrl.searchBar selectedScopeButtonIndex]]];

    // Return YES to cause the search result table view to be reloaded.
    return YES;
}


- (BOOL)searchDisplayController:(UISearchDisplayController *)controller shouldReloadTableForSearchScope:(NSInteger)searchOption
{
    // Tells the table data source to reload when scope bar selection changes
    [self filterContentForSearchText:[_searchDsplyCntrl.searchBar text] scope:
     [[_searchDsplyCntrl.searchBar scopeButtonTitles] objectAtIndex:searchOption]];

    // Return YES to cause the search result table view to be reloaded.
    return YES;
}