objective-c - XMLParsing - 将字符串转换为 NSNumber

Question

有人可以告诉我我需要做什么来解决这个问题

1. 我有一个对象 UserPrefs *userpref
2. 有一个变量叫userpref.userid，它是一个NSNumber
3. 我正在解析 XML，这里的一切都运行良好，直到我将“myxmluseridnumber”元素分配给 userpref.userid

这是错误消息。

将“NSMutableString *_strong”传递给“NSNumber”类型的参数时不兼容的指针类型

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

        if ([elementName isEqualToString:@"User"]) {
            inItemElement = YES;
        }

        if (inItemElement && [elementName isEqualToString:@"myxmluseridnumber"]) {
            capturedCharacters = [[NSMutableString alloc] initWithCapacity:100];
        }
    }

    - (void)parser:(NSXMLParser *)parser foundCharacters:(NSString *)string {
       if(capturedCharacters != nil) {
           [capturedCharacters appendString:string];
       }
    }

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

        if (inItemElement && [elementName isEqualToString:@"myxmluseridnumber"]) {
            NSLog(@"%@ - myxmlnumber", capturedCharacters);
            //This is what is producing my error
            userpref.userid = capturedCharacters;
            capturedCharacters = nil;
        }

        if ([elementName isEqualToString:@"User"]) {
            inItemElement = NO;
        }

    }

谢谢

Answer 1

由于 userid 是一个 NSNumber，因此您应该从字符串 capturedCharacters 创建一个 NSNumber

userpref.userid = [NSNumber numberWithInt:[capturedCharacters intValue]];