无法使用Go获取XML属性

type Person struct {
    Name string `xml:"name"`
    Age  int    `xml:"age"`
}

type PersonAttr struct {
    ID string `xml:"id,attr"`
}

type Person struct {
    Attr PersonAttr `xml:"person"`
    Name string     `xml:"name"`
    Age  int        `xml:"age"`
}

func main() {
    xmlData := `
        <person id="123">
            <name>John Doe</name>
            <age>30</age>
        </person>
    `
    var p Person
    err := xml.Unmarshal([]byte(xmlData), &p)
    if err != nil {
        fmt.Println("XML unmarshal error:", err)
        return
    }
    fmt.Println("ID:", p.Attr.ID)
    fmt.Println("Name:", p.Name)
    fmt.Println("Age:", p.Age)
}