nsxml解析器问题

Question

我对iPhone很满意，以前也这样做过，但现在还不能理解。我正在使用XMLParser并获得如下所示的响应：

username =         {
        text = akhildas;
        type = string;
    };

相反，我期望的是

username = akhildas

我所做的是：

- (NSDictionary *)objectWithData:(NSData *)data
{
// Clear out any old data
[dictionaryStack release];
[textInProgress release];

dictionaryStack = [[NSMutableArray alloc] init];
textInProgress = [[NSMutableString alloc] init];

// Initialize the stack with a fresh dictionary
[dictionaryStack addObject:[NSMutableDictionary dictionary]];

// Parse the XML
NSXMLParser *parser = [[NSXMLParser alloc] initWithData:data];
parser.delegate = self;
BOOL success = [parser parse];

// Return the stack's root dictionary on success
if (success)
{
    NSDictionary *resultDict = [dictionaryStack objectAtIndex:0];
    return resultDict;
}

return nil;
}

#pragma mark -
#pragma mark NSXMLParserDelegate methods

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


// Get the dictionary for the current level in the stack
NSMutableDictionary *parentDict = [dictionaryStack lastObject];

// Create the child dictionary for the new element, and initilaize it with the attributes
NSMutableDictionary *childDict = [NSMutableDictionary dictionary];
[childDict addEntriesFromDictionary:attributeDict];

// If there's already an item for this key, it means we need to create an array
id existingValue = [parentDict objectForKey:elementName];
if (existingValue)
{
    NSMutableArray *array = nil;
    if ([existingValue isKindOfClass:[NSMutableArray class]])
    {
        // The array exists, so use it
        array = (NSMutableArray *) existingValue;
    }
    else
    {
        // Create an array if it doesn't exist
        array = [NSMutableArray array];
        [array addObject:existingValue];

        // Replace the child dictionary with an array of children dictionaries
        [parentDict setObject:array forKey:elementName];
    }

    // Add the new child dictionary to the array
    [array addObject:childDict];

}
else
{
    // No existing value, so update the dictionary
    [parentDict setObject:childDict forKey:elementName];
}

// Update the stack
[dictionaryStack addObject:childDict];
}

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


// Update the parent dict with text info
NSMutableDictionary *dictInProgress = [dictionaryStack lastObject];

// Set the text property
if ([textInProgress length] > 0)
{
    [dictInProgress setObject:textInProgress forKey:kXMLReaderTextNodeKey];

    // Reset the text
    [textInProgress release];
    textInProgress = [[NSMutableString alloc] init];
}

// Pop the current dict
[dictionaryStack removeLastObject];
}
- (void)parser:(NSXMLParser *)parser foundCharacters:(NSString *)string
{
// Build the text value
[textInProgress appendString:string];
}

有没有人有同样的问题并且很好地解决了？

Answer 1

我总是尽量避免使用基于回调(SAX)的NSXMLParser，而倾向于使用DOM解析器来为您创建DOM树模型。我发现DOM解析器要容易得多。

我最喜欢的是GDataXML解析器(由谷歌开发)。它是非常可靠和易于使用的。它只包含2个文件(和libxml2库)，但功能非常强大。它使您不必查找委托方法，也不必担心是否正确遵循了XML结构并以正确的方式提取了对象。

将XML文档映射到Objective-C对象树可以如下所示：

NSData  *xmlData = [[NSMutableData  alloc] initWithContentsOfFile:filePath];
 NSError  *error;
 GDataXMLDocument *doc = [[GDataXMLDocument alloc] initWithData:xmlData 
        options:0 error:&error];
 if (doc != nil)NSLog(@"%@", doc.rootElement);

请参阅这篇关于iPhone解析的非常流行的教程，其中解释了GDataXML：

http://www.raywenderlich.com/725/how-to-read-and-write-xml-documents-with-gdataxml

希望它能让您更轻松地跟踪和解析XML数据。