效果如下：
ViewController.h
1 #import <UIKit/UIKit.h> 2 #import "DropDownListViewController.h" 3 4 @interface ViewController : UITableViewController<UISearchBarDelegate, PassValueDelegate> 5 @property (strong, nonatomic) UISearchBar *searchBar; 6 @property (strong, nonatomic) NSMutableArray *mArrDataSourceOfTableView; 7 @property (strong, nonatomic) NSMutableArray *mArrDataSourceOfSearchBar; 8 @property (strong, nonatomic) DropDownListViewController *ddlViewController; 9 @property (strong, nonatomic) UILabel *lblEmptyDataMsg; 10 11 @end
ViewController.m
1 #import "ViewController.h"
2
3 @interface ViewController ()
4 - (void)layoutUI;
5 - (void)loadData;
6 - (void)updateTableView:(NSString *)searchText;
7 - (void)setDDLHidden:(BOOL)isHidden animated:(BOOL)animated;
8 @end
9
10 @implementation ViewController
11 #define kRowCount 64
12
13 - (void)viewDidLoad {
14 [super viewDidLoad];
15
16 [self layoutUI];
17 }
18
19 - (void)didReceiveMemoryWarning {
20 [super didReceiveMemoryWarning];
21 // Dispose of any resources that can be recreated.
22 }
23
24 #pragma mark - Private Methods
25 - (void)layoutUI {
26 [self loadData];
27
28 self.navigationItem.title = @"在搜索框中实现下拉列表效果";
29
30 _searchBar = [[UISearchBar alloc] initWithFrame:CGRectMake(0, 0, self.tableView.frame.size.width, 50)];
31 _searchBar.delegate = self;
32 _searchBar.prompt = @"数字查询";
33 _searchBar.placeholder = @"请输入0-63之间的数字";
34 _searchBar.keyboardType = UIKeyboardTypeNumberPad;
35 _searchBar.barStyle = UIBarStyleDefault;
36 _searchBar.tintColor = [UIColor blackColor];
37 [_searchBar sizeToFit]; //设置宽高大小自适应
38 self.tableView.tableHeaderView = _searchBar;
39
40 _ddlViewController = [[DropDownListViewController alloc] initWithStyle:UITableViewStylePlain];
41 _ddlViewController.delegate = self;
42 _ddlViewController.view.frame = CGRectMake(22.0, 68.0, 320.0, 0);
43 [self.view addSubview:_ddlViewController.view];
44
45 _lblEmptyDataMsg = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, 200, 50)];
46 CGPoint newPoint = self.view.center;
47 newPoint.y -= 25;
48 _lblEmptyDataMsg.center = newPoint;
49 _lblEmptyDataMsg.text = @"没有相关数据";
50 _lblEmptyDataMsg.textColor = [UIColor grayColor];
51 _lblEmptyDataMsg.textAlignment = NSTextAlignmentCenter;
52 _lblEmptyDataMsg.font = [UIFont systemFontOfSize:20];
53 _lblEmptyDataMsg.hidden = YES;
54 [self.view addSubview:_lblEmptyDataMsg];
55 }
56
57 - (void)viewDidAppear:(BOOL)animated {
58 [super viewDidAppear:animated];
59
60 [self setDDLHidden:YES animated:NO];
61 }
62
63 - (void)loadData {
64 _mArrDataSourceOfTableView = [[NSMutableArray alloc] initWithCapacity:kRowCount];
65 _mArrDataSourceOfSearchBar = [[NSMutableArray alloc] initWithCapacity:kRowCount];
66 for (NSInteger i=0; i<kRowCount; i++) {
67 [_mArrDataSourceOfTableView addObject:[NSString stringWithFormat:@"%ld", (long)i]];
68 _mArrDataSourceOfSearchBar[i] = _mArrDataSourceOfTableView[i];
69 }
70 }
71
72 - (void)updateTableView:(NSString *)searchText {
73 [_mArrDataSourceOfSearchBar removeAllObjects];
74 if (searchText.length == 0) {
75 _mArrDataSourceOfSearchBar = [[NSMutableArray alloc] initWithArray:_mArrDataSourceOfTableView];
76 } else {
77 for (NSString *item in _mArrDataSourceOfTableView) {
78 if ([item hasPrefix:searchText]) {
79 [_mArrDataSourceOfSearchBar addObject:item];
80 }
81 }
82 }
83 //表格视图tableView更新
84 [self.tableView reloadData];
85
86 //设置当UITableView数据源为空数据时，显示提示信息标签_lblEmptyDataMsg
87 _lblEmptyDataMsg.hidden = _mArrDataSourceOfSearchBar.count > 0;
88 }
89
90 - (void)setDDLHidden:(BOOL)isHidden animated:(BOOL)animated {
91 NSInteger ddlHeight = isHidden ? 0 : 180;
92 //声明并实现block代码块setHeightForDDL
93 void (^setHeightForDDL)() = ^() {
94 [_ddlViewController.view setFrame:CGRectMake(22.0, 68.0, 320.0, ddlHeight)];
95 };
96
97 if (animated) {
98 //设置视图变化使用动画效果
99 [UIView beginAnimations:nil context:nil];
100 [UIView setAnimationDuration:0.3];
101 setHeightForDDL();
102 [UIView commitAnimations];
103 } else {
104 setHeightForDDL();
105 }
106
107 }
108
109 #pragma mark - SearchBar
110 - (void)searchBar:(UISearchBar *)searchBar textDidChange:(NSString *)searchText {
111 //必须设置为最顶层；否则在UITableView数据源为空数据后切换，会出现_ddlViewController.view不是最顶层的现象
112 [self.view bringSubviewToFront:_ddlViewController.view];
113
114 _ddlViewController.searchText = searchText;
115 [self setDDLHidden:(searchText.length == 0) animated:YES];
116 [_ddlViewController updateData];
117
118 }
119
120 - (void)searchBarSearchButtonClicked:(UISearchBar *)searchBar {
121 //隐藏自定义的下拉列表视图
122 [self setDDLHidden:YES animated:YES];
123
124 [self updateTableView:searchBar.text];
125 //隐藏键盘
126 [_searchBar resignFirstResponder];
127 }
128
129 #pragma mark - TableView
130 - (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
131 return [_mArrDataSourceOfSearchBar count];
132 }
133
134 - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
135 static NSString *cellIdentifier = @"cellIdentifier";
136 UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:cellIdentifier];
137 if (!cell) {
138 cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:cellIdentifier];
139 }
140 cell.textLabel.text = _mArrDataSourceOfSearchBar[indexPath.row];
141 return cell;
142 }
143
144 #pragma PassValueDelegate
145 - (void)passValue:(NSString *)value {
146 if (value) {
147 _searchBar.text = value;
148 [self searchBarSearchButtonClicked:_searchBar];
149 }
150 }
151
152 @end
PassValueDelegate.h
1 @protocol PassValueDelegate <NSObject> 2 - (void)passValue:(NSString *)value; 3 4 @end
DropDownListViewController.h
1 #import <UIKit/UIKit.h>
2 #import "PassValueDelegate.h"
3
4 @interface DropDownListViewController : UITableViewController
5 {
6 @private
7 NSString *_selectedText;
8 }
9 @property (strong, nonatomic) NSMutableArray *mArrResultList;
10 @property (copy, nonatomic) NSString *searchText;
11 @property (weak, nonatomic) id<PassValueDelegate> delegate;
12
13 - (void)updateData;
14
15 @end
DropDownListViewController.m
1 #import "DropDownListViewController.h"
2
3 @interface DropDownListViewController ()
4 - (void)layoutUI;
5 @end
6
7 @implementation DropDownListViewController
8 #define kRowCount 6
9 #define kHeightForRow 30.0
10
11 - (void)viewDidLoad {
12 [super viewDidLoad];
13
14 [self layoutUI];
15 }
16
17 - (void)didReceiveMemoryWarning {
18 [super didReceiveMemoryWarning];
19 // Dispose of any resources that can be recreated.
20 }
21
22 - (void)layoutUI {
23 self.tableView.layer.borderColor = [UIColor blackColor].CGColor;
24 self.tableView.layer.borderWidth = 1.0;
25
26 _mArrResultList = [[NSMutableArray alloc] initWithCapacity:kRowCount];
27 _searchText = nil;
28 _selectedText = nil;
29 }
30
31 - (void)updateData {
32 [_mArrResultList removeAllObjects];
33 if (_searchText && _searchText.length > 0) {
34 [_mArrResultList addObject:_searchText];
35 for (NSInteger i=1; i<kRowCount; i++) {
36 [_mArrResultList addObject:[NSString stringWithFormat:@"%@%ld", _searchText, (long)i]];
37 }
38 }
39
40 [self.tableView reloadData];
41 }
42
43 #pragma mark - TableView
44 - (NSString *)tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger)section {
45 return nil;
46 }
47
48 - (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
49 return 1;
50 }
51
52 - (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
53 return (_searchText && _searchText.length > 0) ? kRowCount : 0;
54 }
55
56 - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
57 static NSString *cellIdentifier = @"cellIdentifier";
58 UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:cellIdentifier];
59 if (!cell) {
60 cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:cellIdentifier];
61 }
62 cell.textLabel.text = _mArrResultList[indexPath.row];
63 return cell;
64 }
65
66 - (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
67 _selectedText = _mArrResultList[indexPath.row];
68 [_delegate passValue:_selectedText];
69 }
70
71 - (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {
72 return kHeightForRow;
73 }
74
75 @end
AppDelegate.h
1 #import <UIKit/UIKit.h> 2 3 @interface AppDelegate : UIResponder <UIApplicationDelegate> 4 @property (strong, nonatomic) UIWindow *window; 5 @property (strong, nonatomic) UINavigationController *navigationController; 6 7 @end
AppDelegate.m
1 #import "AppDelegate.h"
2 #import "ViewController.h"
3
4 @interface AppDelegate ()
5 @end
6
7 @implementation AppDelegate
8
9 - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
10 _window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
11 ViewController *viewController = [[ViewController alloc] init];
12 _navigationController = [[UINavigationController alloc] initWithRootViewController:viewController];
13 _window.rootViewController = _navigationController;
14 //[_window addSubview:_navigationController.view]; //当_window.rootViewController关联时，这一句可有可无
15 [_window makeKeyAndVisible];
16 return YES;
17 }
18
19 - (void)applicationWillResignActive:(UIApplication *)application {
20 }
21
22 - (void)applicationDidEnterBackground:(UIApplication *)application {
23 }
24
25 - (void)applicationWillEnterForeground:(UIApplication *)application {
26 }
27
28 - (void)applicationDidBecomeActive:(UIApplication *)application {
29 }
30
31 - (void)applicationWillTerminate:(UIApplication *)application {
32 }
33
34 @end
时间： 2024-12-19 22:01:11