即使在初始化后变量也为零

Question

这是代码 config/config.go

const PROJECT_ID = "projectid"

var Ctx = context.Background()

var DSClient *datastore.Client

type Logger struct {

    Pkg string

}

func (l *Logger) Error(v ...interface{}) {

    log.Print("Error|", l.Pkg, ": ", v)

}

func (l *Logger) Info(v ...interface{}) {

    log.Print("Info|", l.Pkg, ": ", v)

}

var propFile = "${env}.properties"

var Props *properties.Properties

func init(){

    Props = properties.MustLoadFile(propFile, properties.UTF8)

    DSClient, err := datastore.NewClient(Ctx, PROJECT_ID)

    if err != nil {

        log.Fatal("Couldn't connect to DataStore: ", err)

    }

    log.Print("DataStore Client: ", DSClient)

}

索引/index.go

    import (

    ...

    "github.com/shwetanka19/project/internal/config"

)

    urs := [] user.User{}

    q := datastore.NewQuery("users").Filter("email=", greq.Email).Limit(1)

    logger.Info("Now Client: ", config.DSClient)

    keys, err := config.DSClient.GetAll(config.Ctx, q, &urs)

日志

DataStore Client: &{0xc000010840 0xc000119d40 projectid}

[Now Client:  <nil>]

为什么 Client 已经初始化了，现在却是 nil 呢？API 调用期间会调用 index.go 中的代码。而 config 在服务器启动时被调用。

Answer 1

当你这样做时DSClient,&nbsp;err&nbsp;:=&nbsp;datastore.NewClient(Ctx,&nbsp;PROJECT_ID)您创建一个新变量DSClient来隐藏另一个变量。您只需要将其更改为：var&nbsp;err&nbsp;error DSClient,&nbsp;err&nbsp;=&nbsp;datastore.NewClient(Ctx,&nbsp;PROJECT_ID)