iphone傳遞價值給其他類

我裏面RootViewController.m一個代碼位：iphone傳遞價值給其他類

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath { 

NSManagedObject *selectedObject = [[self fetchedResultsController] objectAtIndexPath:indexPath]; 
BlogRssParser *blogRss = [[BlogRssParser alloc] init]; 
blogRss.terms = [[selectedObject valueForKey:@"data"] description]; 
//[blogRss setSelectedObject:selectedObject]; 
NSLog(@"%@", blogRss.terms); 

RssFunViewController *rssFun = [[RssFunViewController alloc] initWithNibName:@"RssFunViewController" bundle:nil]; 
[self.navigationController pushViewController:rssFun animated:YES]; 
[rssFun release];

}

所以，當用戶點擊該行，它進入RssFunViewController。但它使用BlogRssParser來填充RssFun的tableview。所以我試圖在它之間取得一個值，並從RootView向BlogRss發送一個值，這樣它就可以用正確的數據填充RssFun。

我有這個在BlogRssParser.m：

-(BOOL)fetchAndParseRss{ 
    NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init]; 

    [UIApplication sharedApplication].networkActivityIndicatorVisible = YES; 

    //To suppress the leak in NSXMLParser 
    [[NSURLCache sharedURLCache] setMemoryCapacity:0]; 
    [[NSURLCache sharedURLCache] setDiskCapacity:0]; 

    NSLog(@"%@", self.terms); 

    NSURL *url = [NSURL URLWithString:[NSString stringWithFormat:@"http://news.search.yahoo.com/rss?ei=UTF-8&p=%@&fr=news-us-ss", self.terms]]; 
    NSLog(@"%@", url); 

    BOOL success = NO; 
    NSXMLParser *parser = [[NSXMLParser alloc] initWithContentsOfURL:url]; 
    [parser setDelegate:self]; 
    [parser setShouldProcessNamespaces:YES]; 
    [parser setShouldReportNamespacePrefixes:YES]; 
    [parser setShouldResolveExternalEntities:NO]; 
    success = [parser parse]; 
    [parser release]; 
    [pool drain]; 
    return success; 
}

在控制檯中，RootView方面的日誌具有正確的值。但是在BlogRssParser中，它出現爲（null）。我已經在BlogRssParser.m中聲明瞭屬性。

這是我宣佈它：

@interface BlogRssParser : NSObject { 
    BlogRss * _currentItem; 
    NSMutableString * _currentItemValue; 
    NSMutableArray * _rssItems; 
    id<BlogRssParserDelegate> _delegate; 
    NSOperationQueue *_retrieverQueue; 
    //NSManagedObject *selectedObject; 
    NSString *terms; 
} 


@property(nonatomic, retain) BlogRss * currentItem; 
@property(nonatomic, retain) NSMutableString * currentItemValue; 
@property(readonly) NSMutableArray * rssItems; 
//@property(nonatomic,retain) NSManagedObject *selectedObject; 
@property(nonatomic, retain) NSString *terms; 

@property(nonatomic, assign) id<BlogRssParserDelegate> delegate; 
@property(nonatomic, retain) NSOperationQueue *retrieverQueue;

來源

2010-11-13 benhowdle89