前面关于复杂类型的转换功能如果大家觉得还不够的话，那么您可以了解下​Scan​转换方法，该方法可以实现对任意参数到​struct/struct​数组​/map/map​数组的转换，并且根据开发者输入的转换目标参数自动识别执行转换。

该方法定义如下：

// Scan automatically calls MapToMap, MapToMaps, Struct or Structs function according to
// the type of parameter `pointer` to implement the converting.
// It calls function MapToMap if `pointer` is type of *map to do the converting.
// It calls function MapToMaps if `pointer` is type of *[]map/*[]*map to do the converting.
// It calls function Struct if `pointer` is type of *struct/**struct to do the converting.
// It calls function Structs if `pointer` is type of *[]struct/*[]*struct to do the converting.
func Scan(params interface{}, pointer interface{}, mapping ...map[string]string) (err error)

我们接下来看几个示例便可快速理解。

自动识别转换Struct

package main

import (
	"github.com/gogf/gf/v2/frame/g"
	"github.com/gogf/gf/v2/util/gconv"
)

func main() {
	type User struct {
		Uid  int
		Name string
	}
	params := g.Map{
		"uid":  1,
		"name": "john",
	}
	var user *User
	if err := gconv.Scan(params, &user); err != nil {
		panic(err)
	}
	g.Dump(user)
}

执行后，输出结果为：

{
	"Name": "john",
	"Uid": 1
}

自动识别转换Struct数组

package main

import (
	"github.com/gogf/gf/v2/frame/g"
	"github.com/gogf/gf/v2/util/gconv"
)

func main() {
	type User struct {
		Uid  int
		Name string
	}
	params := g.Slice{
		g.Map{
			"uid":  1,
			"name": "john",
		},
		g.Map{
			"uid":  2,
			"name": "smith",
		},
	}
	var users []*User
	if err := gconv.Scan(params, &users); err != nil {
		panic(err)
	}
	g.Dump(users)
}

执行后，终端输出：

[
    {
            "Uid": 1,
            "Name": "john"
    },
    {
            "Uid": 2,
            "Name": "smith"
    }
]

自动识别转换Map

package main

import (
	"github.com/gogf/gf/v2/frame/g"
	"github.com/gogf/gf/v2/util/gconv"
)

func main() {
	var (
		user   map[string]string
		params = g.Map{
			"uid":  1,
			"name": "john",
		}
	)
	if err := gconv.Scan(params, &user); err != nil {
		panic(err)
	}
	g.Dump(user)
}

执行后，输出结果为：

{
   "Uid": "1", 
   "Name": "john"
}

自动识别转换Map数组

package main

import (
	"github.com/gogf/gf/v2/frame/g"
	"github.com/gogf/gf/v2/util/gconv"
)

func main() {
	var (
		users  []map[string]string
		params = g.Slice{
			g.Map{
				"uid":  1,
				"name": "john",
			},
			g.Map{
				"uid":  2,
				"name": "smith",
			},
		}
	)
	if err := gconv.Scan(params, &users); err != nil {
		panic(err)
	}
	g.Dump(users)
}

执行后，输出结果为：

[
    {
            "name": "john",
            "uid": "1"
    },
    {
            "name": "smith",
            "uid": "2"
    }
]