iOS: 在UITableView中实现搜索功能关键代码

最终效果图：

主界面：

- (void)viewDidLoad
{
    [super viewDidLoad];
    
    UISearchBar *searchBar = [[UISearchBar alloc] initWithFrame:CGRectMake(0, 0, self.tableView.frame.size.width, searchBarHeight)];
    searchBar.delegate = self;
    self.tableView.tableHeaderView = searchBar;
    [searchBar release];
	
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
    return [[DataController instance].filterContacts count];
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
	//NSLog(@"RootView:cellForRowAtIndexPath");
    static NSString *CellIdentifier = @"Cell";
    
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
    if (cell == nil) {
        cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier] autorelease];
    }

    Contact *contact = [[DataController instance].filterContacts objectAtIndex:indexPath.row];
    cell.textLabel.text = [contact.cardName toString];
    //[contact release]; 不能释放
	
    return cell;
}

 搜索部分：

#pragma mark - Searching

- (void)updateSearchString:(NSString*)aSearchString
{
    [searchString release];
    searchString = [[NSString alloc]initWithString:aSearchString];
	
	[[DataController instance] filterContactsWithLastName:searchString];

    [self.tableView reloadData];
}

- (void)searchBarTextDidBeginEditing:(UISearchBar *)searchBar
{
    [searchBar setShowsCancelButton:YES animated:YES];
    self.tableView.allowsSelection = NO;
    self.tableView.scrollEnabled = NO;
}

- (void)searchBarCancelButtonClicked:(UISearchBar *)searchBar
{   
    [searchBar setShowsCancelButton:NO animated:YES];
    [searchBar resignFirstResponder];
    self.tableView.allowsSelection = YES;
    self.tableView.scrollEnabled = YES;
    searchBar.text=@"";
    [self updateSearchString:searchBar.text];
}

- (void)searchBarSearchButtonClicked:(UISearchBar *)searchBar
{
    self.tableView.allowsSelection = YES;
    self.tableView.scrollEnabled = YES;
    [self updateSearchString:searchBar.text]; 
	[searchBar resignFirstResponder];	//隐藏输入键盘
}

 其中DataController是数据操作类

DataController.h

#import <Foundation/Foundation.h>

@class Contact;

@interface DataController : NSObject {
    NSArray* contacts;
	NSMutableArray *filterContacts;
}

@property (retain, nonatomic)NSArray* contacts;
@property (retain, nonatomic)NSMutableArray* filterContacts;

-(void)filterContactsWithLastName:(NSString*)lastName;

+(DataController*)instance;

@end

DataController.m

#import "DataController.h"
#import "Contact.h"
#import "CardName.h"
#import "XMLParser.h"

@implementation DataController

@synthesize contacts;
@synthesize filterContacts;

+(DataController*)instance
{
    static DataController* instance = nil;
	
    if (!instance) {
        instance = [[DataController alloc]init];
    }
	
    return instance;
}

- (id)init {
	NSLog(@"DataController:init");

    self = [super init];
	
    if (self) {      
		XMLParser *xmlParser = [[XMLParser alloc]init];
		[xmlParser parse];
		self.contacts = xmlParser.contacts;
		self.filterContacts = [[NSMutableArray alloc] initWithArray: contacts];
		[xmlParser release];
    }
	
    return self;
}

- (void)dealloc {
	NSLog(@"DataController:dealloc");
	[self.filterContacts release];
    [self.contacts release];
    [super dealloc];
}

-(void)filterContactsWithLastName:(NSString*)lastName
{
	NSLog(@"filter by %@", lastName);
	[self.filterContacts release];
	self.filterContacts = [[NSMutableArray alloc] initWithArray: contacts];
	
    if (lastName && [lastName length] > 0)
    {
		//Case and diacritic insensitive lookups, such as name contains[cd] "itroen"
		NSString* predicateFormat = @"(cardName.firstName CONTAINS[cd] %@) OR (cardName.middleName CONTAINS[cd] %@) OR (cardName.lastName CONTAINS[cd] %@)";
		NSPredicate *predicate = [NSPredicate predicateWithFormat: predicateFormat, lastName, lastName, lastName];
        [self.filterContacts filterUsingPredicate:predicate];
		//[predicateFormat release];
    }
}

@end

 曾在下一句折腾了差不多一天，原因是之前cardName的属性为first,而不是firstName, 可能first是关键字吧！

NSString* predicateFormat = @"(cardName.firstName CONTAINS[cd] %@) OR (cardName.middleName CONTAINS[cd] %@) OR (cardName.lastName CONTAINS[cd] %@)";