大致如下，一些边缘 case 检查（obj 不是指针）这边忽略了

func parse(ss string, obj interface{}) {
    var (
        v = reflect.ValueOf(obj).Elem()
        f = v.FieldByName("Age")
    )

    if f.CanSet() {
        f.SetString(ss)
    }
}

一种是比较传统的办法，用接口挡一下。但是字段太多的时候会很蠢……

type nameSetable interface{ SetName(string) }
type ageSetable interface{ SetAge(string) }
type gradeSetable interface{ SetGrade(string) }

type student struct {
    Name  string `xlsxCol:"student name"`
    Age   string `xlsxCol:"student age"`
    Grade string `xlsxCol:"student grate"`
}

var _ nameSetable = &student{}
var _ ageSetable = &student{}
var _ gradeSetable = &student{}

func (s *student) SetName(ss string)  { s.Name = ss }
func (s *student) SetAge(ss string)   { s.Age = ss }
func (s *student) SetGrade(ss string) { s.Grade = ss }

type teacher struct {
    Name string `xlsxCol:"teacher name"`
    Age  string `xlsxCol:"teacher age"`
}

var _ nameSetable = &teacher{}
var _ ageSetable = &teacher{}

func (s *teacher) SetName(ss string) { s.Name = ss }
func (s *teacher) SetAge(ss string)  { s.Age = ss }

func parse(ss string, obj interface{}) {
    if s, ok := obj.(nameSetable); ok {
        s.SetName(ss)
    }

    if s, ok := obj.(ageSetable); ok {
        s.SetAge(ss)
    }

    if s, ok := obj.(gradeSetable); ok {
        s.SetGrade(ss)
    }
}

🤮