go gin框架请求参数绑定：ShouldBindQuery绑定struct结构体

package main

import (
  "net/http"

  "github.com/gin-gonic/gin"
)

type User struct {
  ID string `form:"id" json:"id"`
}

func main() {
  r := gin.Default()
  r.GET("user", func(c *gin.Context) {
    var user User
    if err := c.ShouldBindQuery(&user); err != nil {
      c.JSON(http.StatusBadRequest, gin.H{
        "code_": 500,
        "id_":   user.ID,
      })
      return
    }
    c.JSON(http.StatusOK, gin.H{
      "code": 200,
      "id_":  user.ID,
    })
  })
  r.Run()
}