以下来自百度翻译：

若要将请求体绑定到类型，请使用模型绑定。我们目前支持JSON、XML和标准表单值的绑定（Foo= Bar和Bo.BAZ）。

package main

import (
	"github.com/gin-gonic/gin"
	"net/http"
)



func main() {
	router := gin.Default()

	router.POST("/loginJSON", func(c *gin.Context) {
		var json Login
		if err := c.ShouldBindJSON(&json); err != nil {
			c.JSON(http.StatusBadRequest, gin.H{"error": "Login information is not complete"})
			return
		}

		if json.User != "manu" || json.Password != "123" {
			c.JSON(http.StatusUnauthorized, gin.H{"status": "unauthorized"})
			return
		}

		c.JSON(http.StatusOK, gin.H{"status": "you are logged in"})
	})

	router.Run(":8080")
}

type Login struct {
	User     string `form:"user" json:"user" xml:"user"  binding:"required"`
	Password string `form:"password" json:"password" xml:"password" binding:"required"`
}

简单说下，Login结构体，通过binding:"required"进行了必须绑定，就是请求时候，必须带上该参数，还分别进行了form、json、xml类型，这里我们先尝试下json 类型
我们同样是执行几条指令来看看返回都结果提示：

当执行"user":"manu"，只有一个user参数时候，

$ curl -X POST http://localhost:8080/loginJSON 
-H 'content-type:application/json' -d '{"user":"manu"}'

输出结果如下：

{"error":"Login information is not complete"}

$ curl -X POST http://localhost:8080/loginJSON
 -H 'content-type:application/json' -d '{"user":"manu","password":"123d"}'

输出结果如下：

{"status":"unauthorized"}

 $ curl -X POST http://localhost:8080/loginJSON 
 -H 'content-type:application/json' -d '{"user":"manu","password":"123"}'

输出结果如下：

{"status":"you are logged in"}

以下就是绑定xml、form类型的，我只贴出代码即可，用法是一样的

绑定xml

	// Example for binding XML (
	//	<?xml version="1.0" encoding="UTF-8"?>
	//	<root>
	//		<user>user</user>
	//		<password>123</user>
	//	</root>)
	router.POST("/loginXML", func(c *gin.Context) {
		var xml Login
		if err := c.ShouldBindXML(&xml); err != nil {
			c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
			return
		}
		
		if xml.User != "manu" || xml.Password != "123" {
			c.JSON(http.StatusUnauthorized, gin.H{"status": "unauthorized"})
			return
		} 
		
		c.JSON(http.StatusOK, gin.H{"status": "you are logged in"})
	})

绑定form

	// Example for binding a HTML form (user=manu&password=123)
	router.POST("/loginForm", func(c *gin.Context) {
		var form Login
		// This will infer what binder to use depending on the content-type header.
		if err := c.ShouldBind(&form); err != nil {
			c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
			return
		}
		
		if form.User != "manu" || form.Password != "123" {
			c.JSON(http.StatusUnauthorized, gin.H{"status": "unauthorized"})
			return
		} 
		
		c.JSON(http.StatusOK, gin.H{"status": "you are logged in"})
	})

BindQueryShouldBindQuery函数只绑定查询参数，而不绑定POST数据。

我现在只BindQuery来试验，ShouldBindQuery我测试输出结果一样

package main

import "log"
import "github.com/gin-gonic/gin"

type Person struct {
	Name    string `form:"name"`
	Address string `form:"address"`
}

func main() {
	route := gin.Default()
	route.Any("/testing", startPage)
	route.Run(":8080")
}
func startPage(c *gin.Context) {
	var person Person
	if c.BindQuery(&person) == nil {
		log.Println("====== Only Bind Query String ======")
		log.Println(person.Name)
		log.Println(person.Address)
	}
	c.String(200, "Success")
}

通过执行curl -X GET "localhost:8080/testing?name=eason&address=xyz"
最后log输出日志如下：

Bind:only bind the query or post data！！！

BindJson:only bind the json data！！！

package main

import "log"
import "github.com/gin-gonic/gin"

type Person struct {
	Name    string `form:"name" json:"name"`
	Address string `form:"address" json:"address"`
}

func main() {
	route := gin.Default()
	route.Any("/testing", startPage)
	route.Run(":8080")
}
func startPage(c *gin.Context) {
	var person Person

	if c.Bind(&person) == nil {
		log.Println("====== Bind By Query String ======")
		log.Println(person.Name)
		log.Println(person.Address)
	}

	if c.BindJSON(&person) == nil {
		log.Println("====== Bind By JSON ======")
		log.Println(person.Name)
		log.Println(person.Address)
	}


	c.String(200, "Success")
}

测试如下：
1、输入指令测试Bind,参数
curl -X GET "localhost:8080/testing?name=appleboy&address=xyz"
输出结果如下：

2018/09/20 17:35:19 ====== Bind By Query String ======
2018/09/20 17:35:19 appleboy
2018/09/20 17:35:19 xyz

2、输入指令测试Bind,用来测试formdata,这里我用了postman

3、输入指令来测试BindJSON

zhiliaodeMBP:go zhiliao$ curl -X GET localhost:8080/testing --data '{"name":"JJ", "address":"xyz"}' -H "Content-Type:application/json"

输出结果如下：

2018/09/20 17:31:46 ====== Bind By JSON ======
2018/09/20 17:31:46 JJ
2018/09/20 17:31:46 xyz