002、GO之反射

01、反射字段和方法

 1 package main
 2 
 3 import (
 4     "fmt"
 5     "reflect"
 6 )
 7 
 8 type Name struct {
 9     name string
10     age  int
11 }
12 
13 func (n Name) Print() {
14     fmt.Println(n.name)
15 }
16 
17 func main() {
18     n1 := Name{"abc", 10}
19     Info(n1)
20 }
21 
22 func Info(a interface{}) {
23     t := reflect.TypeOf(a)
24     v := reflect.ValueOf(a)
25 
26     fmt.Println("Type name:", t.Name())
27 
28     //不是struct类型时，获取不到Field信息
29     if k := t.Kind(); k != reflect.Struct {
30         fmt.Println("传入的类型不是struct类型")
31         return
32     }
33 
34     fmt.Println("字段")
35     for i := 0; i < t.NumField(); i++ {
36         f := t.Field(i)
37         val := v.Field(i)
38         fmt.Printf("%6s %v=%v\n", f.Name, f.Type, val)
39     }
40     fmt.Println("方法", t.NumMethod())
41     for i := 0; i< t.NumMethod(); i ++ {
42         m := t.Method(i)
43         fmt.Printf("%6s  %v\n", m.Name, m.Type)
44     }
45 }

02、反射匿名字段

 1 package main
 2 
 3 import (
 4     "fmt"
 5     "reflect"
 6 )
 7 
 8 type Name struct {
 9     name string
10     age  int
11 }
12 
13 type Person struct {
14     Name
15     job string
16 }
17 
18 func main() {
19     p := Person{
20         Name: Name{"hello", 10},
21         job:  "software engineer",
22     }
23     t := reflect.TypeOf(p)
24     fmt.Printf("%#v\n", t.FieldByIndex([]int{0,1}))
25 }

reflect.StructField{Name:"age", PkgPath:"main", Type:(*reflect.rtype)(0x4cda00), Tag:"", Offset:0x10, Index:[]int{1}, Anonymous:false}

03、反射修改值

 1 package main
 2 
 3 import (
 4     "fmt"
 5     "reflect"
 6 )
 7 
 8 type Name struct {
 9     Name string
10     age  int
11 }
12 
13 func main() {
14     n := Name{"aaa", 10}
15     v := reflect.ValueOf(&n)
16     if v.Kind() != reflect.Ptr {
17         fmt.Println("不可修改")
18         return
19     } else {
20         v = v.Elem()
21     }
22     f := v.FieldByName("Name")
23     if !f.IsValid() {
24         fmt.Println("未找到字段")
25         return
26     }
27     if !f.CanSet() {
28         fmt.Println("找到的字段不可修改")
29         return
30     }
31     if f.Kind() == reflect.String {
32         f.SetString("abc")
33     }
34     fmt.Println(n)
35 }

04、反射调用方法

 1 package main
 2 
 3 import (
 4     "fmt"
 5     "reflect"
 6 )
 7 
 8 type Name struct {
 9     Name string
10     age  int
11 }
12 
13 func(n *Name) SetName(name string) {
14     n.Name = name
15 }
16 
17 func main() {
18     n := Name{"aaa", 10}
19     v := reflect.ValueOf(&n)
20     vm := v.MethodByName("SetName")
21     if !vm.IsValid() {
22         fmt.Println("获取的方法不合法")
23         return
24     }
25     vm.Call([]reflect.Value {reflect.ValueOf("abc")})
26     fmt.Printf("%v", n)
27 }

posted on 2020-05-02 09:21 TBBS 阅读(184) 评论(0) 编辑收藏举报