NSXMLParser問題 - SeismicXML示例

Question

嘿， 我必須在我的iOS應用程序中解析XML。我將Apple的SeismicXML Sample作爲我的基礎，但我遇到了一個非常奇怪的行爲。

這些都是我的解析器methodes：

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

if ([elementName isEqualToString:kEntryElementName]) { 
    Photo *photo = [[Photo alloc] init]; 
    self.currentPhotoObject = photo; 
    [photo release]; 

} else if ([elementName isEqualToString:kTitleElementName] || 
     [elementName isEqualToString:kLocationElementName] || 
     [elementName isEqualToString:kAuthorElementName]) { 

    accumulatingParsedCharacterData = YES; 

    [currentParsedCharacterData setString:@""]; 
} 

}

- (void)parser:(NSXMLParser *)parser didEndElement:(NSString *)elementName 
            namespaceURI:(NSString *)namespaceURI 
           qualifiedName:(NSString *)qName {  
if ([elementName isEqualToString:kEntryElementName]) { 
    NSLog(@"Did End - Titel:%@", self.currentPhotoObject.titleText); 
    NSLog(@"Did End - Location:%@", self.currentPhotoObject.locationText); 
    NSLog(@"Did End - Author:%@", self.currentPhotoObject.author); 

    [self.currentParseBatch addObject:self.currentPhotoObject]; 

    parsedPhotosCounter++; 
    if ([self.currentParseBatch count] >= kMaximumNumberOfPhotosToParse) { 
     [self performSelectorOnMainThread:@selector(addPhotosToList:) 
           withObject:self.currentParseBatch 
          waitUntilDone:NO]; 
     self.currentParseBatch = [NSMutableArray array]; 
    } 
}  

else if ([elementName isEqualToString:kTitleElementName]) { 
    self.currentPhotoObject.titleText = self.currentParsedCharacterData; 
} 

else if ([elementName isEqualToString:kAuthorElementName]) { 
    self.currentPhotoObject.author = self.currentParsedCharacterData; 

} 

else if ([elementName isEqualToString:kLocationElementName]) { 
    self.currentPhotoObject.locationText = self.currentParsedCharacterData;   
} 

accumulatingParsedCharacterData = NO; 

}

- (void)parser:(NSXMLParser *)parser foundCharacters:(NSString *)string { 
if (accumulatingParsedCharacterData) { 
    // If the current element is one whose content we care about, append 'string' 
    // to the property that holds the content of the current element. 
    // 
    [self.currentParsedCharacterData appendString:string]; 
} 

}

一切的偉大工程中，XML數據來自正確。解析器解析所有應該的東西。 問題出在解析器didEndElement方法中。

else if ([elementName isEqualToString:kTitleElementName]) { 
    self.currentPhotoObject.titleText = self.currentParsedCharacterData; 
} 

當我通過NSLog的 「self.currentPhotoObject.titleText」，我得到的分析數據的權利。但後來：

else if ([elementName isEqualToString:kAuthorElementName]) { 
    self.currentPhotoObject.author = self.currentParsedCharacterData; 

} 

當我拿到「self.currentPhotoObject.titleText」的NSLog的，並從「self.currentPhotoObject.author」在這裏，無論是給我的作者。 在第三個解析的方法中它是相同的。所有三個屬性（titleText，author和locationText）都是locationText。

我不知道爲什麼.titleText例如在解析器設置.author時更改。

我已將doublechecked至少10次，並將其與SeismicXML示例進行比較，但找不到問題。 請幫幫我。我很感謝每一個提示！

迎接塞巴斯蒂安

PS：我在.m文件屬性：

@interface ParseOperation() <NSXMLParserDelegate> 
@property (nonatomic, retain) Photo *currentPhotoObject; 
@property (nonatomic, retain) NSMutableArray *currentParseBatch; 
@property (nonatomic, retain) NSMutableString *currentParsedCharacterData; 
@end 

@implementation ParseOperation 

@synthesize photoData, currentPhotoObject, currentParsedCharacterData, currentParseBatch; 

Answer 1

這是因爲分配相同NSMutableString實例，這一切屬性。

1）聲明author,titleText,locationText屬性爲copy以避免將來出現這種情況。

2）要返回的NSMutableString值或指定給一些

self.currentPhotoObject.titleText = [[self.currentParsedCharacterData copy] autorelease];