Libxml2中使用xpath解析xml问题

//hack to remove xmlns => avoid xpath search not works  
//如果节点xml节点含有xmlns，这个时候用xpath是匹配不出节点内容的，只好删掉了，找这个原因不容易啊 - -|||
 xmlStr = [xmlStr stringByReplacingOccurrencesOfString:@"xmlns" withString:@"noNSxml"];  
 NSMutableArray* contents = [NSMutableArray array];  
  
 NSError* error = nil;  
 DDXMLDocument* xmlDoc = [[DDXMLDocument alloc] initWithXMLString:xmlStr options:0 error:&error];  
  
 if (error) {  
 NSLog(@"%@",[error localizedDescription]);  
 return nil;  
 }  
  
 NSArray* resultNodes = nil;  
 resultNodes = [xmlDoc nodesForXPath:@"//audio | //text | //image | //img" error:&error];  
  
 if (error) {  
 NSLog(@"%@",[error localizedDescription]);  
 return nil;  
 }  
  
 for(DDXMLElement* resultElement in resultNodes)  
 {  
 NSString* name = [resultElement name];  
 //audio , text or other media type  
 NSString* fileName = [[resultElement attributeForName:@"src"] stringValue];  
 // 0.txt  
 }