我创建了一个从博客中获取信息的应用程序。我能够成功获取信息并将其显示在表格视图中。然后我创建了一个搜索栏和一个搜索显示控制器，以便我可以搜索信息。当我运行它时，没有错误，它会获取并显示信息。但是当我在搜索栏中输入一个字母时，即使有从那个字母开始的单词，表格视图中也没有单元格。
这是我的 .m 文件中的代码
@implementation EventsTableViewController
@synthesize searchBar, filteredEventsArray, eventNamesArray, isFiltered, eventsDictionary;
- (id)initWithStyle:(UITableViewStyle)style
{
self = [super initWithStyle:style];
if (self) {
// Custom initialization
}
return self;
}
- (void)viewDidLoad
{
[super viewDidLoad];
self.eventNamesArray = [NSMutableArray array];
self.eventsDictionary = [NSMutableDictionary dictionary];
}
- (void)viewWillAppear:(BOOL)animated
{
[super viewWillAppear:animated];
[self searchForEvents];
}
//Json Parsing
- (void)searchForEvents
{
NSString *eventsSearchUrlString = [NSString stringWithFormat:@"https://www.googleapis.com/blogger/v3/blogs/1562818803553764290/posts?key=AIzaSyBTOxz-vPHgzIkw9k88hDKd99ILTaXTt0Y"];
NSURL *eventsSearchUrl = [NSURL URLWithString:eventsSearchUrlString];
NSURLRequest *eventsSearchUrlRequest = [NSURLRequest requestWithURL:eventsSearchUrl];
NSURLSession *sharedUrlSession = [NSURLSession sharedSession];
NSURLSessionDataTask *searchEventsTask =
[sharedUrlSession dataTaskWithRequest:eventsSearchUrlRequest completionHandler:
^(NSData *data, NSURLResponse *response, NSError *error)
{
dispatch_async(dispatch_get_main_queue(),
^{
[UIApplication sharedApplication].networkActivityIndicatorVisible = NO;
if(error)
{
UIAlertView *searchAlertView = [[UIAlertView alloc] initWithTitle:@"Error" message:@"Please check your internet connection" delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil];
[searchAlertView show];
}
else
{
NSString *resultString = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
NSLog(@"Search results: %@", resultString);
NSError *jsonParseError = nil;
NSDictionary *jsonDictionary = [NSJSONSerialization JSONObjectWithData:data options:0 error:&jsonParseError];
if(jsonParseError)
{
UIAlertView *jsonParseErrorAlert = [[UIAlertView alloc] initWithTitle:@"Error" message:jsonParseError.localizedDescription delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil];
[jsonParseErrorAlert show];
}
else
{
for(NSString *key in jsonDictionary.keyEnumerator)
{
NSLog(@"First level key: %@", key);
}
[self.eventNamesArray removeAllObjects];
[self.eventsDictionary removeAllObjects];
NSArray *searchResultsArray = [jsonDictionary objectForKey:@"items"];
//NSLog(@"test%@",searchResultsArray);
for(NSDictionary *eventsInfoDictionary in searchResultsArray)
{
Events *event = [[Events alloc] init];
event.eventName = [eventsInfoDictionary objectForKey:@"title"];
event.eventDescription =[eventsInfoDictionary objectForKey:@"content"];
NSLog(@"Event Name : %@",event.eventName);
NSLog(@"Event Description : %@",event.eventDescription);
NSString *eventsAsStrings = [event.eventName substringToIndex:1];
NSMutableArray *eventsInArray = [self.eventsDictionary objectForKey:eventsAsStrings];
if(!eventsInArray)
{
eventsInArray = [NSMutableArray array];
[self.eventNamesArray addObject:eventsAsStrings];
}
[eventsInArray addObject:event];
[self.eventsDictionary setObject:eventsInArray forKey:eventsAsStrings];
if ([event.eventDescription containsString:@"<br />"]) {
NSString* eventDescrip = event.eventDescription;
NSString* stringWithoutHTMLtags = [eventDescrip stringByReplacingOccurrencesOfString:@"<br />" withString:@""];
event.eventDescription = stringWithoutHTMLtags;
}
NSLog(@"Event Name : %@",event.eventName);
NSLog(@"Event Description : %@",event.eventDescription);
}
[self.eventNamesArray sortedArrayUsingComparator:^NSComparisonResult(Events *obj1, Events *obj2) {
Events *time1 = obj1;
Events *time2 = obj2;
if (time1 > time2) {
return (NSComparisonResult)NSOrderedDescending;
}
else if (time1 < time2) {
return (NSComparisonResult)NSOrderedAscending;
}
return (NSComparisonResult)NSOrderedSame;
}];
[self.tableView reloadData];
}
}
});
}];
[UIApplication sharedApplication].networkActivityIndicatorVisible = YES;
[searchEventsTask resume];
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
- (void)searchBar:(UISearchBar *)searchBar textDidChange:(NSString *)searchText {
if (searchText.length == 0) {
isFiltered = NO;
}
else {
isFiltered = YES;
}
for (NSString *eventName in eventNamesArray) {
NSRange eventNameRange = [eventName rangeOfString:searchText options:NSCaseInsensitiveSearch];
if (eventNameRange.location != NSNotFound) {
[filteredEventsArray addObject:eventName];
}
}
[self.tableView reloadData];
}
#pragma mark - Table view data source
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
if (isFiltered == YES) {
return filteredEventsArray.count;
}
else {
return self.eventNamesArray.count;
}
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
NSArray *eventsWithFirstLetter;
if (isFiltered == YES) {
NSString *firstLetter = [self.filteredEventsArray objectAtIndex:section];
eventsWithFirstLetter = [self.eventsDictionary objectForKey:firstLetter];
return eventsWithFirstLetter.count;
}
else {
NSString *firstLetter = [self.eventNamesArray objectAtIndex:section];
eventsWithFirstLetter = [self.eventsDictionary objectForKey:firstLetter];
return eventsWithFirstLetter.count;
}
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = @"eventTitleCell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier forIndexPath:indexPath];
Events *event;
if (isFiltered == YES) {
NSString *firstLetter = [self.filteredEventsArray objectAtIndex:indexPath.section];
NSArray *eventsWithFirstLetter = [self.eventsDictionary objectForKey:firstLetter];
event = [eventsWithFirstLetter objectAtIndex:indexPath.row];
cell.textLabel.text = event.eventName;
}
else {
NSString *firstLetter = [self.eventNamesArray objectAtIndex:indexPath.section];
NSArray *eventsWithFirstLetter = [self.eventsDictionary objectForKey:firstLetter];
event = [eventsWithFirstLetter objectAtIndex:indexPath.row];
cell.textLabel.text = event.eventName;
}
return cell;
}
-(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
NSString *firstLetter = [self.eventNamesArray objectAtIndex:indexPath.section];
NSArray *eventsWithFirstLetter = [self.eventsDictionary objectForKey:firstLetter];
Events *event = [eventsWithFirstLetter objectAtIndex:indexPath.row];
UIStoryboard *mainStoryboard = [UIStoryboard storyboardWithName:@"Main" bundle: nil];
DescriptionViewController *descriptionViewController = (DescriptionViewController*)[mainStoryboard instantiateViewControllerWithIdentifier: @"descriptionController"];
descriptionViewController.eventNameDesc = event.eventDescription;
descriptionViewController.navigationItem.title = event.eventName;
[self.navigationController pushViewController:descriptionViewController animated:YES];
}
@end