GO 语言错误处理

下载编译工具时package github.com/go-xorm/cmd/xorm: cannot download, $GOPATH not set. For more details see: go help gopath

用下面命令可解决

sudo env GOPATH=/Volumes/work/go/fox:/Volumes/work/go/fox/bin go get github.com/go-xorm/cmd/xorm

1.invalid method expression service.AdminUser.Auth (needs pointer receiver: (*service.AdminUser).Auth)

指针只能使用指针方式调用

service.AdminUser.Auth

要改为以下方式调用

(*service.AdminUser).Auth

2.invalid method expression service.AdminUser.Auth (needs pointer receiver: (*service.AdminUser).Auth)

改为如下调用

var admUser *service.AdminUser
admUser.Auth(xxx)

3.cannot use id (type int64) as type int in argument to models.GetAdminById

原因：

int/uint 其值范围与平台有关，所以 int32 != int int64 != int

这里要使用 strconv.Atoi 自动转换

解决方法

int_id, _ := strconv.Atoi(uid)
这个时候在传入int_id
models.GetAdminById(int_id)

4.Golang Struct 转 json 键名首字母小写

来源 https://www.zhihu.com/question/34447868

//感谢大神们回答，为方便大家参考，我这里给个例子吧

package main

import (
"encoding/json"
"fmt"
)

type ColorGroup struct {
ID     int      `json:"id"`
Name   string   `json:"name"`
Colors []string `json:"colors"`
}

func main() {
group := ColorGroup{
ID:     1,
Name:   "Reds",
Colors: []string{"Crimson", "Red", "Ruby", "Maroon"},
}
b, err := json.Marshal(group)
if err != nil {
fmt.Println("error:", err)
}
fmt.Println(string(b))
}

5.Handler crashed with error runtime error: invalid memory address or nil pointer dereference

一般报这个错误原因

1.值为nil

解决方法

找到这个位置，值为nil 判断一下再输出或者赋值

5.cannot use str (type interface {}) as type string in argument to time.Parse: need type assertion

cannot use str (type interface {}) as type string in argument to time.Parse: need type assertion

报错行

date, err = time.Parse(layout, string) 这一行报错
date = str 这一行报错

原函数

func Format(str interface{}, layout string) string {
var date time.Time
var err error
//判断变量类型
switch str.(type) {
case string:
//如果是字符串则转换成 标准日期时间格式
fmt.Println(str)
date, err = time.Parse(layout, string)
if err != nil {
return ""
}
case time.Time:
date = str
}

return date.Format(layout)
}

解决后函数

func Format(str interface{}, layout string) string {
var date time.Time
var err error
//判断变量类型
switch str.(type) {
case string:
//如果是字符串则转换成 标准日期时间格式
fmt.Println(str)
date, err = time.Parse(layout, str.(string))
if err != nil {
return ""
}
case time.Time:
date = str.(time.Time)
}

return date.Format(layout)
}

6.cannot use tmp.Format(“2006-01-02 15:04:05”) (type string) as type time.Time in assignment

或者

cannot use XXX (type string) as type XXXX in assignment

原因：

被你赋值的那个变量或结构体或者其他什么的，被你赋值的类型与要赋值的类型不符

解决：

类型转换，类型要一样才可以赋值

7.cannot use arr (type []string) as type []interface {} in argument to WhereAnd

原因：[]string不能直接转换为[]interface {}类型

解决：

arr:=[]string{"A","B"}
inter := make([]interface{}, arrCount)
for y, x := range arr {
inter[y] = x
}
func WhereAnd(value ...interface{}){
.....
}