进一步澄清“如何用objective c实现UISearchController”
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【中文标题】进一步澄清“如何用objective c实现UISearchController”【英文标题】:Further clarification of "How to implement UISearchController with objective c" 【发布时间】:2015-11-25 00:04:59 【问题描述】:我一直在尝试通过关注***线程来实现UISearchController
:
How to implement UISearchController with objective c
和 Apples 的文档,但无法使其正常工作。当初始控制器(EVTSearchViewController
定义为UIViewController
)符合UISearchBarDelegate, UISearchControllerDelegate, UISearchResultsUpdating, UITableViewDelegate
(我也需要使其与UITableViewDelegate
兼容,因为我使它成为其他UITableViewController
类型EVTSearchResultsViewController *resultsController
s tableView 的代表)代表出现了,我看到我的.xib
带有UISearchBar
和@ 987654336@,我点击搜索栏开始输入:
当我输入一个字母时,搜索栏消失并且什么也没有显示:
首先,我不希望搜索栏消失。其次,updateSearchResultsForSearchController
似乎根本没有被调用,因为NSLog()
在那里设置在我在搜索栏中输入时不会产生任何输出。
我有.xib
用于EVTSearchViewController
,它有一个UISearchBar
,我正在连接到相应的属性:IBOutlet UISearchBar *searchBar
,然后指向 UISearchControllers 的搜索栏:
self.searchBar = self.searchController.searchBar
还有UITableView
,我在.xib
中放在UISearchBar
下方。我在EVTSearchViewController
中使用的另一个控制器是EVTSearchResultsViewController
,它是UITableViewController
,它没有.xib
。
下面是viewDidLoad
和updateSearchResultsForSearchController
方法的代码:
- (void)viewDidLoad
_resultsController = [[EVTSearchResultsViewController alloc] init];
_searchController = [[UISearchController alloc] initWithSearchResultsController:_resultsController];
self.searchController.searchResultsUpdater = self;
self.searchController.searchBar.placeholder = nil;
[self.searchController.searchBar sizeToFit];
self.searchBar = self.searchController.searchBar;
// we want to be the delegate for our filtered table so didSelectRowAtIndexPath is called for both tables
self.resultsController.tableView.delegate = self;
self.searchController.delegate = self;
self.searchController.dimsBackgroundDuringPresentation = YES; // default is YES
self.searchController.searchBar.delegate = self; // so we can monitor text changes + others
// Search is now just presenting a view controller. As such, normal view controller
// presentation semantics apply. Namely that presentation will walk up the view controller
// hierarchy until it finds the root view controller or one that defines a presentation context.
//
self.definesPresentationContext = YES; // know where you want UISearchController to be displayed
- (void)updateSearchResultsForSearchController:(UISearchController *)searchController
// update the filtered array based on the search text
NSString *searchText = searchController.searchBar.text;
NSLog(@"searchText: %@", searchText);
if (searchText == nil)
// If empty the search results are the same as the original data
self.searchResults = [[[EVTItemStore sharedStore] allItems] mutableCopy];
else
NSMutableArray *searchResults = [[NSMutableArray alloc] init];
NSArray *allEvents = [[EVTItemStore sharedStore] allItems];
NSLog(@"allEvents: %@", allEvents);
for (EVTItem *event in allEvents)
/*if ([event.number containsString:searchText] || [[phoneMO.closrr_id filteredId] containsString:searchText] || [[phoneMO.contact.fullname lowercaseString] containsString:[searchText lowercaseString]])
[searchResults addObject:phoneMO];
*/
if ([event.eventName containsString:searchText])
[searchResults addObject:event];
self.searchResults = searchResults;
// hand over the filtered results to our search results table
EVTSearchResultsViewController *resultsController = (EVTSearchResultsViewController *)self.searchController.searchResultsController;
resultsController.filteredEvents = self.searchResults;
[resultsController.tableView reloadData];
EVTSearchViewController
中定义的各个@properties
:
@interface EVTSearchViewController ()
@property (weak, nonatomic) IBOutlet UISearchBar *searchBar;
@property (nonatomic, strong) UISearchController *searchController;
@property (nonatomic, strong) EVTSearchResultsViewController *resultsController;
@property (nonatomic, strong) NSMutableArray *searchResults;
// For state restoration
@property BOOL searchControllerWasActive;
@property BOOL searchControllerSearchFieldWasFirstResponder;
@end
那么,这里是EVTSearchResultsViewController
的代码:
#import "EVTSearchResultsViewController.h"
@implementation EVTSearchResultsViewController
- (instancetype)init
// Call the superclass's designated initializer
self = [super initWithStyle:UITableViewStylePlain];
if (self)
return self;
- (void)viewDidLoad
[super viewDidLoad];
[self.tableView registerClass:[UITableViewCell class]
forCellReuseIdentifier:@"UISearchViewCell"];
- (void)didReceiveMemoryWarning
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
- (NSInteger)tableView:(UITableView *)tableView
numberOfRowsInSection:(NSInteger)section
return [self.filteredEvents count];
- (UITableViewCell *)tableView:(UITableView *)tableView
cellForRowAtIndexPath:(NSIndexPath *)indexPath
UITableViewCell *cell =
[tableView dequeueReusableCellWithIdentifier:@"UISearchViewCell"
forIndexPath:indexPath];
cell.textLabel.text = self.filteredEvents[indexPath.row];
return cell;
@end
上面EVTSearchResultsViewController
的方法根本没有被调用,这让我看起来很奇怪,那我们为什么需要它呢?
我尝试按照 Apple 文档推荐的方式设置 UISearchBar
:
self.resultsTableView.tableHeaderView = self.searchController.searchBar;
但它给了我一个无响应的搜索框,所以当按下时没有任何反应。
有人可以帮忙解决这个问题吗?上面链接的另一个问题也可以澄清。谢谢。
【问题讨论】:
您的实现似乎过于复杂。您通常希望将 uisearchbar 添加到要搜索的 tableview 中,而不是分布在多个类和 xib 中。尝试从一个非常简单的示例从头开始,直到您了解编码模式。 好吧,我相信所有的事情都是必需的,应该以这种方式(或类似方式)完成,再简单不过了。如果你看一下苹果文档,它已经很复杂了:developer.apple.com/library/ios/documentation/UIKit/Reference/… 现在调用这些方法,所以我更好地了解工作流程。我现在有两个主要问题:当一个视图覆盖另一个视图时,图像在上面表示的一个问题;另一个是updateSearchResultsForSearchController
中的NSString *searchText = searchController.searchBar.text
在我输入文本时没有设置。
我现在遇到的主要问题是上面显示的问题,当一个视图运行在另一个视图之上时。我解决了设置文本的问题(我只看到正确的 NSLog() 输出)
您应该使用文档中的这一行:self.tableView.tableHeaderView = self.searchController.searchBar;正如我在第一条评论中建议的那样,请参阅您发送给我的链接以获取更多详细信息。
【参考方案1】:
所以,我解决了这个问题并使用UISearchController
实现了基本搜索。下面是我们实现基本搜索需要做的事情:
-
创建两个没有
.xib
文件的UITableViewControllers
类。是的,应该没有.xib
文件,我们只是创建了两个类。在下面的代码中,他们的名字是EVTSearchViewController
和EVTSearchResultsViewController
。
使控制器之一符合委托:<UISearchBarDelegate, UISearchControllerDelegate, UISearchResultsUpdating>
这里是EVTSearchViewController
的头文件代码:
#import <UIKit/UIKit.h>
@interface EVTSearchViewController : UITableViewController <UISearchBarDelegate, UISearchControllerDelegate, UISearchResultsUpdating>
@end
这是EVTSearchResultsViewController
的标题:
#import <UIKit/UIKit.h>
@interface EVTSearchResultsViewController : UITableViewController
@property (nonatomic, strong) NSMutableArray *filteredEvents;
@end
NSMutableArray *filteredEvents
将保存搜索结果。我们不应该在EVTSearchViewController.m
中实现任何UITableViewController
委托方法,而应该在EVTSearchResultsViewController.m
中实现。
这是EVTSearchViewController
的上半部分:
#import "EVTSearchViewController.h"
#import "EVTSearchResultsViewController.h"
// Importing the class that stores `EVTItem` object classes
#import "EVTItemStore.h"
#import "EVTItem.h"
@interface EVTSearchViewController ()
@property (nonatomic, strong) UISearchController *searchController;
// We created this class
@property (nonatomic, strong) EVTSearchResultsViewController *resultsController;
// array to hold the results of the search
@property (nonatomic, strong) NSMutableArray *searchResults;
@end
这是EVTSearchViewController
的viewDidLoad:
方法的代码:
- (void)viewDidLoad
[super viewDidLoad];
self.resultsController = [[EVTSearchResultsViewController alloc] init];
self.searchController = [[UISearchController alloc] initWithSearchResultsController:self.resultsController];
self.searchController.searchResultsUpdater = self;
self.searchController.searchBar.placeholder = nil;
[self.searchController.searchBar sizeToFit];
// This line of code is very important. Here we are using apple docs'
// suggestion. UITableViewController has tableView property, so
// we are just setting tableView`s header to apples' UISearchController`s' `searchBar property
self.tableView.tableHeaderView = self.searchController.searchBar;
self.searchController.delegate = self;
// default is YES
self.searchController.dimsBackgroundDuringPresentation = YES;
// so we can monitor text changes + other changes
self.searchController.searchBar.delegate = self;
// know where you want UISearchController to be displayed
self.definesPresentationContext = YES;
然后我们给EVTSearchViewController
添加如下方法:
- (void)updateSearchResultsForSearchController:(UISearchController *)searchController
// update filtered array based on the search text
NSString *searchText = searchController.searchBar.text;
if (searchText == nil)
// If empty the search results should be the same as the original data
self.searchResults = [[[EVTItemStore sharedStore] allItems] mutableCopy];
else
NSMutableArray *searchResults = [[NSMutableArray alloc] init];
// [[EVTItemStore sharedStore] allItems] message retrieves
// all of the objects that I have in datastore EVTItemStore
NSArray *allEvents = [[EVTItemStore sharedStore] allItems];
// EVTItem class has a property eventName which we are using
// for searching, then adding it to our searchResults array
for (EVTItem *event in allEvents)
if ([event.eventName containsString:searchText])
[searchResults addObject:event];
self.searchResults = searchResults;
// hand over the filtered results to our search results table
EVTSearchResultsViewController *resultsController = (EVTSearchResultsViewController *)self.searchController.searchResultsController;
resultsController.filteredEvents = self.searchResults;
[resultsController.tableView reloadData];
另一个控制器的EVTSearchResultsViewController
@implementation 部分如下所示:
@implementation EVTSearchResultsViewController
- (instancetype)init
// Call the superclass's designated initializer
self = [super initWithStyle:UITableViewStylePlain];
if (self)
return self;
- (NSInteger)tableView:(UITableView *)tableView
numberOfRowsInSection:(NSInteger)section
return [self.filteredEvents count];
- (UITableViewCell *)tableView:(UITableView *)tableView
cellForRowAtIndexPath:(NSIndexPath *)indexPath
UITableViewCell *cell =
[tableView dequeueReusableCellWithIdentifier:@"UISearchViewCell"
forIndexPath:indexPath];
EVTItem *event = self.filteredEvents[indexPath.row];
cell.textLabel.text = event.eventName;
return cell;
- (void)viewDidLoad
[super viewDidLoad];
[self.tableView registerClass:[UITableViewCell class]
forCellReuseIdentifier:@"UISearchViewCell"];
@end
就是这样。如果我们需要进一步自定义我们的单元格,我们应该能够通过将UISearchViewCell.xib
设置为EVTSearchResultsViewController
并使用以下viewDidLoad
来代替:
- (void)viewDidLoad
[super viewDidLoad];
// Load the NIB file
UINib *nib = [UINib nibWithNibName:@"UISearchViewCell" bundle:nil];
// Register this NIB which contains the cell
[self.tableView registerNib:nib forCellReuseIdentifier:@"UISearchViewCell"];
【讨论】:
非常感谢您的一切。 :)以上是关于进一步澄清“如何用objective c实现UISearchController”的主要内容,如果未能解决你的问题,请参考以下文章