Golang：获取具有字段名称作为字符串的基础结构
问题描述：
How can I get the underlying value of a field having the fields name as a string?
I understand I need to use reflection but if I do will I have to continue using it throughout my code? Is there any way to assert?
I would just like to get the value of the field, the underlying struct, in this case a []Dice.
http://play.golang.org/p/KYOH8C7TAl
type Dice struct {
In int
}
type SliceNDice struct {
Unknown []Dice
}
func main() {
structure := SliceNDice{make([]Dice, 10)}
refValue := reflect.ValueOf(&structure).Elem().FieldByName(string("Unknown"))
slice := refValue.Slice(0, refValue.Len())
// cannot range over slice (type reflect.Value)
//for i,v := range slice {
// fmt.Printf("%v %v
", i, v.In)
//}
for i := 0; i < slice.Len(); i++ {
v := slice.Index(i)
// v.In undefined (type reflect.Value has no field or method In)
fmt.Printf("%v %v
", i, v.In)
}
}
答
If you know that the "Unknown" field is of type []Dice, you can use Value.Interface to get the underlying value and convert it with a type assertion:
slice := refValue.Interface().([]Dice)
for i,v := range slice {
fmt.Printf("%v %v
", i, v.In)
}