UISearchDisplayController简单使用

最近在做一个简单的app入门，中间有一个页面用到了搜索框，本来以为很简单的控件，没想到用到的时候才发现很麻烦。

搜索框使用过程大约有以下几个状态：不活跃－活跃－输入关键词－根据关键词动态列出相关结果－选中搜索结果或取消搜索

// ViewController.h
#import <UIKit/UIKit.h>

@interface ViewController : UIViewController<UITableViewDataSource, UITableViewDelegate, UISearchBarDelegate, UISearchDisplayDelegate>
//相关协议


@property (strong, nonatomic) NSMutableArray *dataList;//搜索数据源
@property (strong, nonatomic) NSMutableArray *searchList;//搜索结果

@property (strong, nonatomic) UITableView *tableView;//数据源tableview


@end

// ViewController.m
#import "ViewController.h"

@interface ViewController ()

@property (nonatomic) UISearchDisplayController *searchDisplayController;

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    self.dataList = [NSMutableArray arrayWithCapacity:10];
    self.tableView = [[UITableView alloc]initWithFrame:CGRectMake(0, 104, self.view.bounds.size.width, self.view.bounds.size.height - 40)];
    for (NSInteger i = 0; i < 10; i++) {
        [self.dataList addObject:[NSString stringWithFormat:@"%ld-yang",i]];
    }
    
    self.tableView.delegate = self;
    self.tableView.dataSource = self;

    UISearchBar *searchBar = [[UISearchBar alloc]initWithFrame:CGRectMake(0, 64, self.view.bounds.size.width, 40)];
    [searchBar setPlaceholder:@"关键字搜索"];
    searchBar.delegate = self;
    
    [self.view addSubview:searchBar];
    
    self.searchDisplayController = [[UISearchDisplayController alloc]initWithSearchBar:searchBar contentsController:self];
    
    _searchDisplayController.delegate = self;

    [_searchDisplayController.searchResultsTableView registerClass:[UITableViewCell class] forCellReuseIdentifier:@"cell"];
    _searchDisplayController.searchResultsTableView.dataSource = self;
    _searchDisplayController.searchResultsTableView.delegate = self;
    
    [self.view addSubview:self.tableView];
    
}- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
　　
    if (tableView == self.searchDisplayController.searchResultsTableView) {
        return [self.searchList count];
    }else{
        return [self.dataList count];
    }
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"cell"];
    if (cell == nil) {
        cell = [[UITableViewCell alloc]initWithStyle:UITableViewCellStyleDefault reuseIdentifier:@"cell"];
    }

    if (tableView == self.tableView){//判断当前tableview是否为搜索结果
        [cell.textLabel setText:self.dataList[indexPath.row]];
    }else{
        [cell.textLabel setText:self.searchList[indexPath.row]];
    }
    
    return cell;
}

//协议方法：开始搜索
- (BOOL)searchBarShouldBeginEditing:(UISearchBar *)searchBar
{
    NSLog(@"search begin");
    searchBar.frame = CGRectMake(0, 20, 320, 44);
    [self.searchDisplayController setActive:YES];
    return YES;
}

//协议方法：搜索结束
- (BOOL)searchBarShouldEndEditing:(UISearchBar *)searchBar
{
    NSLog(@"search end");
    searchBar.frame = CGRectMake(0, 64, 320, 44);
    [self.searchDisplayController setActive:NO];
    return YES;
}

//关键词变化时实时更新搜索结果
- (BOOL)searchDisplayController:(UISearchDisplayController *)controller shouldReloadTableForSearchString:(NSString *)searchString
{
    NSPredicate *preicate = [NSPredicate predicateWithFormat:@"SELF CONTAINS[c]%@",searchString];
　　

　　//清空结果数组
    [self.searchList removeAllObjects];

    //过滤数据
    NSArray *a = [_dataList filteredArrayUsingPredicate:preicate];
    self.searchList = [NSMutableArray arrayWithArray:a];

    //刷新表格
    return YES;
}


@end