要将 UISearchBar 添加到 UITableView，需要执行以下操作：
- 声明并初始化 UISearchBar
- 声明并初始化 UISearchDisplayController
- 将 searchBar 添加到 tableView
- 实现 UISearchDisplayController 委托
- 在头文件中，我声明了我的 searchBar、searchDisplayController 和包含要显示的数据的数组。
ViewController.h：
#import
@interface ViewController : UITableViewController
{
NSArray *originalData;
NSMutableArray *searchData;
UISearchBar *searchBar;
UISearchDisplayController *searchDisplayController;
}
@end
我还在该类中添加了 2 个委托：UISearchBarDelegate 和 UISearchDisplayDelegate，没有，searchBar 根本不起作用！
初始化数据：
//ViewController.m
- (id)initWithStyle:(UITableViewStyle)style
{
self = [super initWithStyle:style];
if (self) {
NSArray *group1 = [[NSArray alloc] initWithObjects:@"Napoli", @"Juventus", @"Inter", @"Milan", @"Lazio", nil];
NSArray *group2 = [[NSArray alloc] initWithObjects:@"Real Madrid", @"Barcelona", @"Villareal", @"Valencia", @"Deportivo", nil];
NSArray *group3 = [[NSArray alloc] initWithObjects:@"Manchester City", @"Manchester United", @"Chelsea", @"Arsenal", @"Liverpool", nil];
originalData = [[NSArray alloc] initWithObjects:group1, group2, group3, nil];
searchData = [[NSMutableArray alloc] init];
}
return self;
}
现在我们需要初始化我们的两个对象，我注释了代码来解释我的工作：
//ViewController.m
- (void)viewDidLoad
{
[super viewDidLoad];
searchBar = [[UISearchBar alloc] initWithFrame:CGRectMake(0, 0, 320, 44)];
/*the search bar widht must be > 1, the height must be at least 44
(the real size of the search bar)*/
searchDisplayController = [[UISearchDisplayController alloc] initWithSearchBar:searchBar contentsController:self];
/*contents controller is the UITableViewController, this let you to reuse
the same TableViewController Delegate method used for the main table.*/
searchDisplayController.delegate = self;
searchDisplayController.searchResultsDataSource = self;
//set the delegate = self. Previously declared in ViewController.h
self.tableView.tableHeaderView = searchBar; //this line add the searchBar
//on the top of tableView.
}
我决定跳过有关 tableView 单元初始化的部分，您可以在可下载的源代码中找到它。 :)
当 tableView 准备好后，就可以实现 UISearchDisplayControllerDelegate 了！
委托有很多方法来控制搜索的各个方面，但最重要的是
- (BOOL)searchDisplayController:(UISearchDisplayController *)controller shouldReloadTableForSearchString:(NSString *)searchString
每次在 searchBar 中插入新字符时都会调用此方法，您将获取 searchString，通过表格元素执行搜索并返回 YES。
- (BOOL)searchDisplayController:(UISearchDisplayController *)controller shouldReloadTableForSearchString:(NSString *)searchString
{
[searchData removeAllObjects];
/*before starting the search is necessary to remove all elements from the
array that will contain found items */
NSArray *group;
/* in this loop I search through every element (group) (see the code on top) in
the "originalData" array, if the string match, the element will be added in a
new array called newGroup. Then, if newGroup has 1 or more elements, it will be
added in the "searchData" array. shortly, I recreated the structure of the
original array "originalData". */
for(group in originalData) //take the n group (eg. group1, group2, group3)
//in the original data
{
NSMutableArray *newGroup = [[NSMutableArray alloc] init];
NSString *element;
for(element in group) //take the n element in the group
{ //(eg. @"Napoli, @"Milan" etc.)
NSRange range = [element rangeOfString:searchString
options:NSCaseInsensitiveSearch];
if (range.length > 0) { //if the substring match
[newGroup addObject:element]; //add the element to group
}
}
if ([newGroup count] > 0) {
[searchData addObject:newGroup];
}
[newGroup release];
}
return YES;
}
就是这样！此方法将在所有元素中执行全文搜索。当搜索结束时，tableView 会自行重新加载。查看源代码以查看其他详细信息。
Download source file (Link UPDATED! (04.01.2016) )