使用本教程，我制作了一个 iPhone 博客应用程序。它使用创建的数组的计数来设置行数。我不想做每一个项目，因为现在有 200 多个并且还在增长。当我为部分中的行返回任何数字时，它总是崩溃，错误约为 0 超出空数组的范围。我还需要从本教程中调整什么以仅允许前 20 个项目显示在 tableview 中？
更新：我认为我正在取得一些进展。在对数组进行排序的 reqeustFinished 方法中，我对其进行了编辑以使其成为：
NSMutableArray *entries = [NSMutableArray array];
[self parseFeed:doc.rootElement entries:entries];
[entries removeLastObject];
[[NSOperationQueue mainQueue] addOperationWithBlock:^{
for (RSSEntry *entry in entries) {
int insertIdx = [_allEntries indexForInsertingObject:entry sortedUsingBlock:^(id a, id b) {
RSSEntry *entry1 = (RSSEntry *) a;
RSSEntry *entry2 = (RSSEntry *) b;
return [entry1.articleDate compare:entry2.articleDate];
}];
NSLog(@"%@", entries);
[_allEntries insertObject:entry atIndex:insertIdx];
[self.tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:[NSIndexPath indexPathForRow:insertIdx inSection:0]]
withRowAnimation:UITableViewRowAnimationRight];
将行添加到 removeLastObject 条目，删除第一项（理想情况下，这是我第一天想要的唯一一项）。是否有其他方法可以让我删除索引处的一系列对象？
这是我为表视图类和数据源提供的代码。
- (void)refresh {
self.allEntries = [NSMutableArray array];
self.queue = [[[NSOperationQueue alloc] init] autorelease];
self.feeds = [NSArray arrayWithObjects:@"addressofxmlfile",
nil];
for (NSString *feed in _feeds) {
NSURL *url = [NSURL URLWithString:feed];
ASIHTTPRequest *request = [ASIHTTPRequest requestWithURL:url];
[request setDelegate:self];
[_queue addOperation:request];
}
}
- (void)viewDidLoad {
[super viewDidLoad];
self.refreshControl = [[UIRefreshControl alloc] init];
[self.refreshControl addTarget:self action:@selector(refreshInvoked:forState:) forControlEvents:UIControlEventValueChanged];
[self refresh];
}
-(void) refreshInvoked:(id)sender forState:(UIControlState)state {
// Refresh table here...
[_allEntries removeAllObjects];
[self.tableView reloadData];
[self refresh];
}
- (void)parseRss:(GDataXMLElement *)rootElement entries:(NSMutableArray *)entries {
NSArray *channels = [rootElement elementsForName:@"channel"];
for (GDataXMLElement *channel in channels) {
NSString *blogTitle = [channel valueForChild:@"title"];
NSArray *items = [channel elementsForName:@"item"];
for (GDataXMLElement *item in items) {
NSString *articleTitle = [item valueForChild:@"title"];
NSString *articleUrl = [item valueForChild:@"guid"];
NSString *articleDateString = [item valueForChild:@"pubdate"];
NSDate *articleDate = [NSDate dateFromInternetDateTimeString:articleDateString formatHint:DateFormatHintRFC822];
NSString *articleImage = [item valueForChild:@"description"];
NSDateFormatter * dateFormatter = [[[NSDateFormatter alloc] init] autorelease];
[dateFormatter setTimeStyle:NSDateFormatterShortStyle];
[dateFormatter setDateStyle:NSDateFormatterMediumStyle];
NSString *dateofarticle = [dateFormatter stringFromDate:articleDate];
NSString *days = [articleImage substringFromIndex:7];
RSSEntry *entry = [[[RSSEntry alloc] initWithBlogTitle:blogTitle
articleTitle:articleTitle
articleUrl:articleUrl
articleDate:articleDate
articleImage:articleImage
date:thedate] autorelease];
[entries addObject:entry];
}
}
}
- (void)parseFeed:(GDataXMLElement *)rootElement entries:(NSMutableArray *)entries {
if ([rootElement.name compare:@"rss"] == NSOrderedSame) {
[self parseRss:rootElement entries:entries];
}else {
NSLog(@"Unsupported root element: %@", rootElement.name);
}
}
- (void)requestFinished:(ASIHTTPRequest *)request {
[_queue addOperationWithBlock:^{
NSError *error;
GDataXMLDocument *doc = [[GDataXMLDocument alloc] initWithData:[request responseData]
options:0 error:&error];
if (doc == nil) {
NSLog(@"Failed to parse %@", request.url);
} else {
NSMutableArray *entries = [NSMutableArray array];
[self parseFeed:doc.rootElement entries:entries];
[[NSOperationQueue mainQueue] addOperationWithBlock:^{
for (RSSEntry *entry in entries) {
int insertIdx = [_allEntries indexForInsertingObject:entry sortedUsingBlock:^(id a, id b) {
RSSEntry *entry1 = (RSSEntry *) a;
RSSEntry *entry2 = (RSSEntry *) b;
return [entry1.articleDate compare:entry2.articleDate];
}];
[_allEntries insertObject:entry atIndex:insertIdx];
[self.tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:[NSIndexPath indexPathForRow:insertIdx inSection:0]]
withRowAnimation:UITableViewRowAnimationRight];
}
}];
}
}];
[self.refreshControl endRefreshing];
}
- (void)requestFailed:(ASIHTTPRequest *)request {
NSError *error = [request error];
NSLog(@"Error: %@", error);
[self refresh];
}
#pragma mark -
#pragma mark Table view data source
// Customize the number of sections in the table view.
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
// [tableView setBackgroundColor:[UIColor redColor]];
return 1;
}
// Customize the number of rows in the table view.
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
return [_allEntries count];
}
// Customize the appearance of table view cells.
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *CellIdentifier = @"Cell";
Cell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[Cell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier];
}
RSSEntry *entry = [_allEntries objectAtIndex:indexPath.row];
CALayer * l = [cell.imageView layer];
[l setMasksToBounds:YES];
[l setCornerRadius:11];
[l setBorderWidth:2.0];
[l setBorderColor:[[UIColor blackColor] CGColor]];
NSDateFormatter * dateFormatter = [[[NSDateFormatter alloc] init] autorelease];
[dateFormatter setTimeZone:[NSTimeZone localTimeZone]];
[dateFormatter setTimeStyle:NSDateFormatterShortStyle];
[dateFormatter setDateStyle:NSDateFormatterShortStyle];
NSString *articleDateString = [dateFormatter stringFromDate:entry.articleDate];
UIFont *cellFont = [UIFont fontWithName:@"Papyrus" size:19];
UIFont *cellFont2 = [UIFont fontWithName:@"Papyrus" size:17];
// cell.imageView.image = [UIImage imageNamed:@"icon@2x.png"];
cell.textLabel.text = entry.date;
cell.detailTextLabel.text = entry.articleTitle;
cell.detailTextLabel.textColor = [UIColor blackColor];
cell.textLabel.font = cellFont;
cell.detailTextLabel.font = cellFont2;
return cell;
}
-(CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {
return 73.4;
}