在iOS中用NSXML解析数据

Question

我试图使用NSXMLR解析Wordpress RSS提要中的数据。我的问题是导出分析过的数据。到目前为止，

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

    currentElement = [elementName copy];

    if ([elementName isEqualToString:@"item"]){

        currentTitle = [[NSMutableString alloc] init];
        item = [[NSMutableDictionary alloc] init];
    }

}

这个类

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


    if ([elementName isEqualToString:@"item"]){
        [item setObject:currentTitle forKey:@"title"];
    }

    [stories addObject:item];
}


- (void) parser:(NSXMLParser *)parser foundCharacters:(NSString *)string{

    if ([currentElement isEqualToString:@"title"]){
        [currentTitle appendString:string];
    }

}

NSMutableArray *故事；NSMutableDictionary *项目；

所以在ViewDidLoad实现中，我有

//declare the object of allocated variable
NSData *xmlData=[[NSData alloc]initWithContentsOfURL:[NSURL URLWithString:@"URL"]];// URL that given to parse.

//allocate memory for parser as well as
xmlParserObject =[[NSXMLParser alloc]initWithData:xmlData];
[xmlParserObject setDelegate:self];

//asking the xmlparser object to beggin with its parsing
[xmlParserObject parse];



NSLog(@"%@", [item objectForKey:@"title"]);

我的问题是，我只打印一个对象，我有倍数元素。我怎样才能让它扫描其中的每一个，并打印它们全部。

提前谢谢。

Answer 1

如果我正确理解您的代码，item保存当前解析的项，数组stories保存所有项。

因此，您必须首先分配stories数组：

stories = [[NSMutableArray alloc] init];

然后执行解析(但应该添加错误检查)：

NSData *xmlData=[[NSData alloc]initWithContentsOfURL:[NSURL URLWithString:@"URL"]];
xmlParserObject =[[NSXMLParser alloc]initWithData:xmlData];
[xmlParserObject setDelegate:self];
if (![xmlParserObject parse]) {
    // Parsing failed, report error...
}

最后，打印数组的内容：

for (NSDictionary *story in stories) {
    NSLog(@"%@", [story objectForKey:@"title"]);
}

didEndElement方法可能应该如下所示：

- (void) parser:(NSXMLParser *)parser didEndElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName{
    if ([elementName isEqualToString:@"item"]){
        [item setObject:currentTitle forKey:@"title"];
        [stories addObject:item]; // <-- MOVED INTO THE IF-BLOCK
    }
}