iOS UISearchController的使用

 

在iOS9中，UISearchDisplayController 已經被UISearchController替代。搜索框是一種常用的控件。

假設我們要滿足下圖的需求，產生100個“數字+三個隨機字母”，然后搜索包含某個字母的結果。

那么，該怎么做呢？

 

#import "ViewController.h"

@interface ViewController ()<UITableViewDelegate,UITableViewDataSource,UISearchControllerDelegate,UISearchResultsUpdating>

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

//searchController
@property (strong, nonatomic)  UISearchController *searchController;

//數據源
@property (strong,nonatomic) NSMutableArray  *dataList;

@property (strong,nonatomic) NSMutableArray  *searchList;

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    
    _dataList = [NSMutableArray array];
    _searchList = [NSMutableArray array];
    
    self.dataList=[NSMutableArray arrayWithCapacity:100];
    
    //產生100個“數字+三個隨機字母”
    for (NSInteger i=0; i<100; i++) {
        [self.dataList addObject:[NSString stringWithFormat:@"%ld%@",(long)i,[self shuffledAlphabet]]];
    }
    
    _tableView = [[UITableView alloc]initWithFrame:CGRectMake(0, 20,[UIScreen  mainScreen].bounds.size.width ,[UIScreen  mainScreen].bounds.size.height)];
        
    _tableView.delegate = self;
    _tableView.dataSource = self;
    _tableView.separatorStyle = UITableViewCellSelectionStyleNone;
    
    //創建UISearchController
    _searchController = [[UISearchController alloc]initWithSearchResultsController:nil];
    //設置代理
    _searchController.delegate = self;
    _searchController.searchResultsUpdater= self;
    
    //設置UISearchController的顯示屬性，以下3個屬性默認為YES
    //搜索時，背景變暗色
    _searchController.dimsBackgroundDuringPresentation = NO;
    //搜索時，背景變模糊
    _searchController.obscuresBackgroundDuringPresentation = NO;
    //隱藏導航欄
    _searchController.hidesNavigationBarDuringPresentation = NO;
    
    _searchController.searchBar.frame = CGRectMake(self.searchController.searchBar.frame.origin.x, self.searchController.searchBar.frame.origin.y, self.searchController.searchBar.frame.size.width, 44.0);
    
    // 添加 searchbar 到 headerview
    self.tableView.tableHeaderView = _searchController.searchBar;
    
    [self.view addSubview:_tableView];
    
    
    // Do any additional setup after loading the view, typically from a nib.
}


//產生3個隨機字母
- (NSString *)shuffledAlphabet {
    
    NSMutableArray * shuffledAlphabet = [NSMutableArray arrayWithArray:@[@"A",@"B",@"C",@"D",@"E",@"F",@"G",@"H",@"I",@"J",@"K",@"L",@"M",@"N",@"O",@"P",@"Q",@"R",@"S",@"T",@"U",@"V",@"W",@"X",@"Y",@"Z"]];
    
    NSString *strTest = [[NSString alloc]init];
    for (int i=0; i<3; i++) {
        int x = arc4random() % 25;
        strTest = [NSString stringWithFormat:@"%@%@",strTest,shuffledAlphabet[x]];
    }
    
    return strTest;
    
}


//設置區域的行數
-(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section{
    if (self.searchController.active) {
        return [self.searchList count];
    }else{
        return [self.dataList count];
    }
}


//返回單元格內容
-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
    static NSString *flag=@"cell";
    UITableViewCell *cell=[tableView dequeueReusableCellWithIdentifier:flag];
    if (cell==nil) {
        cell=[[UITableViewCell alloc]initWithStyle:UITableViewCellStyleDefault reuseIdentifier:flag];
    }
    if (self.searchController.active) {
        [cell.textLabel setText:self.searchList[indexPath.row]];
    }
    else{
        [cell.textLabel setText:self.dataList[indexPath.row]];
    }
    return cell;
}


#pragma mark - UISearchControllerDelegate代理

//測試UISearchController的執行過程

- (void)willPresentSearchController:(UISearchController *)searchController
{
    NSLog(@"willPresentSearchController");
}

- (void)didPresentSearchController:(UISearchController *)searchController
{
    NSLog(@"didPresentSearchController");
}

- (void)willDismissSearchController:(UISearchController *)searchController
{
    NSLog(@"willDismissSearchController");
}

- (void)didDismissSearchController:(UISearchController *)searchController
{
    NSLog(@"didDismissSearchController");
}

- (void)presentSearchController:(UISearchController *)searchController
{
    NSLog(@"presentSearchController");
}


-(void)updateSearchResultsForSearchController:(UISearchController *)searchController {
    
    NSLog(@"updateSearchResultsForSearchController");
    NSString *searchString = [self.searchController.searchBar text];
    NSPredicate *preicate = [NSPredicate predicateWithFormat:@"SELF CONTAINS[c] %@", searchString];
    if (self.searchList!= nil) {
        [self.searchList removeAllObjects];
    }
    //過濾數據
    self.searchList= [NSMutableArray arrayWithArray:[_dataList filteredArrayUsingPredicate:preicate]];
    //刷新表格
    [self.tableView reloadData];
}

 

UISearchController代理方法的執行過程：

UISearchController的使用步驟：

1、創建

//創建UISearchController
    _searchController = [[UISearchController alloc]initWithSearchResultsController:nil];

 

2、設置代理

    //設置代理
    _searchController.delegate = self;
    _searchController.searchResultsUpdater= self;

 

3、設置屬性

    //設置UISearchController的顯示屬性，以下3個屬性默認為YES
    //搜索時，背景變暗色
    _searchController.dimsBackgroundDuringPresentation = NO;
    //搜索時，背景變模糊
    _searchController.obscuresBackgroundDuringPresentation = NO;
    //隱藏導航欄
    _searchController.hidesNavigationBarDuringPresentation = NO;

 

4、實現代理

- (void)willPresentSearchController:(UISearchController *)searchController;
- (void)didPresentSearchController:(UISearchController *)searchController;
- (void)willDismissSearchController:(UISearchController *)searchController;
- (void)didDismissSearchController:(UISearchController *)searchController;
- (void)presentSearchController:(UISearchController *)searchController;

- (void)updateSearchResultsForSearchController:(UISearchController *)searchController;

 

 

注意點：

1、如果你希望在同一個視圖中顯示搜索結果，則通過[[UISearchController alloc]initWithSearchResultsController:nil]。但是這是不支持TVOS，請提供TVOS一定要指定結果控制器。

[[UISearchController alloc]initWithSearchResultsController:VC]，可以實現指定結果控制器。