Xcode 使用GData库更新节点

您好，我正在使用Gdata库，我被困在一个地方，我想从xml节点更新特定的数据。下面是我试图更新的代码

-(void)UpdateTheXMLNode { NSArray *docdirpath = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); NSString *fileLoc = [[docdirpath objectAtIndex:0] stringByAppendingPathComponent:@"SomeXML.xml"]; NSData *xmlData = [NSData dataWithContentsOfFile:fileLoc]; GDataXMLDocument *doc = [[GDataXMLDocument alloc]initWithData:xmlData options:0 error:nil]; NSArray *a = [doc.rootElement elementsForName:@"row"]; NSLog(@"data before = %@",[[[a objectAtIndex:0] childAtIndex:1]stringValue]); [[[a objectAtIndex:0] childAtIndex:1]setStringValue:@"Yahooo"]; [a writeToFile:fileLoc atomically:YES]; NSLog(@"data after = %@",[[[a objectAtIndex:0] childAtIndex:1]stringValue]); } -（void）UpdateTheXMLNode { NSArray*docdirpath=NSSearchPathForDirectoriesInDomains（NSDocumentDirectory，NSUserDomainMask，是）； NSString*fileLoc=[[docdirpath objectAtIndex:0]stringByAppendingPathComponent:@“SomeXML.xml”]； NSData*xmlData=[NSData dataWithContentsOfFile:fileLoc]； GDataXMLDocument*doc=[[GDataXMLDocument alloc]initWithData:xmlData选项：0错误：nil]； NSArray*a=[doc.rootElement elementsForName:@“row”]； NSLog（@“前面的数据=%@，[[a objectAtIndex:0]childAtIndex:1]stringValue]）； [[a objectAtIndex:0]childAtIndex:1]setString值：@“Yahooo”]； [a writeToFile:fileLoc原子性：YES]； NSLog（@“data after=%@，[[a objectAtIndex:0]childAtIndex:1]stringValue]）； } 但是，唉，它现在给了我任何结果，所以请帮我解决它