的NSXMLParser擺脫EXC_BAD_ACCESS時ARC啓用

Question

iOS的初學者在這裏。我想對於一個新聞網站創建一個RSS閱讀器中，RSS解析器工作正常，但它給人的異常EXC_BAD_ACCESS（代碼= 2個地址= 0xC的），如果它與ARC編譯啓用。

這是我如何調用解析器：（在我的視圖控制器）

NSMutableArray* articleListMainPage; 

- (void)viewDidLoad 
{ 
    NSURL *mainFeed = [[NSURL alloc]initWithString:@"http://my.domain.com/rss.xml"]; 
    NSXMLParser *nsXmlParser = [[NSXMLParser alloc] initWithContentsOfURL:mainFeed]; 
    NewsParser *myparser = [[NewsParser alloc] initNewsParser]; 
    [nsXmlParser setDelegate:myparser]; 

    if ([nsXmlParser parse]) { 
     NSLog(@"Parsed article count : %i", [myparser.articles count]); 
     articleListMainPage = [myparser.articles copy]; 
    } else { 
     NSLog(@"Error parsing document!"); 
    } 
    nsXmlParser = nil; 
    mainFeed = nil; 
    myparser = nil; // This line throws the exception. 

    [super viewDidLoad]; 
} 

和這裏的解析器本身：

// NewsParser.m 
#import "NewsParser.h" 
#import "RSSEntry.h" 

@implementation NewsParser 

@synthesize article, articles, currValue; 

- (NewsParser *) initNewsParser 
{ 
    if (self = [super init]) return self; else return nil; 
} 

- (void)parser:(NSXMLParser *)parser 
    didStartElement:(NSString *)elementName 
    namespaceURI:(NSString *)namespaceURI 
    qualifiedName:(NSString *)qualifiedName 
    attributes:(NSDictionary *)attributeDict { 

    if ([elementName isEqualToString:@"channel"]) { 
     self.articles = [[NSMutableArray alloc] init]; 
    } 
    if ([elementName isEqualToString:@"item"]) { 
     self.article = [[ArticleEntry alloc] init]; 
    } 
} 

- (void)parser:(NSXMLParser *)parser foundCharacters:(NSString *)string { 
    if (!currValue) { 
     self.currValue = [[NSMutableString alloc] initWithString:string]; 
    } else { 
     [self.currValue appendString:string]; 
    } 
} 

- (void)parser:(NSXMLParser *)parser 
    didEndElement:(NSString *)elementName 
    namespaceURI:(NSString *)namespaceURI 
    qualifiedName:(NSString *)qName { 

    if ([elementName isEqualToString:@"channel"]) { 
     return; 
    } 

    if ([elementName isEqualToString:@"item"]) { 
     [self.articles addObject:self.article]; 
     self.article = nil; 
    } else { 
     if ([[NSArray arrayWithObjects:@"title",@"link",@"description",nil] containsObject:elementName]) 
      [self.article setValue:self.currValue forKey:elementName]; 
    } 
    self.currValue = nil; 
} 

@end 

//NewsParser.h 

#import <Foundation/Foundation.h> 
#import "RSSEntry.h" 

@interface NewsParser : NSXMLParser <NSXMLParserDelegate> { 
    NSMutableString *currValue; 
    NSMutableArray *articles; 
    ArticleEntry *article; 
} 
- (NewsParser *) initNewsParser; 
@property (nonatomic,retain) ArticleEntry *article; 
@property (nonatomic,retain) NSMutableArray *articles; 
@property (nonatomic,retain) NSMutableString *currValue; 
@end 

..我使用保存在RSS條目的類。

//RSSEntry.h 
#import <Foundation/Foundation.h> 

@interface ArticleEntry : NSObject { 
    NSString *title; 
    NSString *link; 
    NSString *description; 
} 

@property (nonatomic, retain) NSString *title; 
@property (nonatomic, retain) NSString *link; 
@property (nonatomic, retain) NSString *description; 

- (id)initNewArticle:(NSString*)_title url:(NSString*)_link description:(NSString*)_desc; 

@end 

//RSSEntry.m 

#import "RSSEntry.h" 

@implementation ArticleEntry 
@synthesize title,link,description; 
- (id)initNewArticle:(NSString *)_title url:(NSString *)_link description:(NSString *)_desc 
{ 
    if ((self = [super init])) { 
     title = [_title copy]; 
     link = [_link copy]; 
     description = [_desc copy]; 
     return self; 
    } 
    else return nil; 
} 
@end 

就像我說的，它的工作原理沒有ARC很好，但我想知道如果我做一些我不應該做（例如保留的東西，我不應該或不正確釋放的東西/在編碼中過度放置東西）。

感謝您的時間..

Answer 1

因此，這裏的一個問題是，你宣佈NewsParser是的NSXMLParser，它不應該是一個子類。它應該是NSObject的子類（或其他適當的東西）在NewsParser.h

所以，試試這個：

@interface NewsParser : NSObject <NSXMLParserDelegate> 

順便說一句，你有內存泄漏有沒有ARC。分析器可以幫助您解決這些問題，如果您打算在沒有ARC的情況下再次編譯此代碼。不管有沒有ARC，沒有垃圾收集器在這裏（這聽起來就好像你是在一個計數？）