xml在iOS中解析show null

Question

我必須讀取一個XML文件並讀取XML文件中的id屬性，但該字典將爲空。 XML是：

<?xml version='1.0' encoding='UTF-8'?> 
<root> 
<event id="2"></event> 
</root> 

我的代碼：

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

    NSLog(@"elementName is %@", elementName); 
    // elementName is root 
    NSLog(@"AttributeDict is %@", attributeDict); 
    //AttributeDict is { } why? 
    //I must extract "id" in event but does not entry 

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

    NSLog(@" %@", elementName); 

} 

} 

Answer 1

你需要做的，如：

- (void)parser:(NSXMLParser *)parser didStartElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qualifiedName 
attributes:(NSDictionary *)attributeDict 
{ 
    if ([elementName isEqualToString:@"event"]) 
    { 
     NSLog(@" %@", [attributeDict objectForKey:@"id"); 
    } 

} 

元素root沒有任何屬性，這就是attributeDict顯示爲爲什麼空，當elementName是根。