问题

我正在尝试从我的基于Go的应用程序中调用Google Cloud的组成员资格API。我查看了Go的文档这里的文档，但我不确定如何在Go中编写一个简单的代码来实现这一点。

这是我尝试编写的代码：

package main

import (
	"context"
	"google.golang.org/api/cloudidentity/v1beta1"
)

func main() {
	ctx := context.Background()
	cloudidentityService, err := cloudidentity.NewService(ctx)
	res, err := cloudidentity.Groups.Memberships.Lookup('placeholder-value', 'memberKey.namespace')
}

运行时，我收到错误消息"cannot refer to unexported name cloudidentity.groups"。

我对Google Cloud和Go都是新手。我的任务是查找用户是否是Google Cloud中给定组的一部分。

<details>
<summary>英文:</summary>

I am trying to call google cloud [groups memberships apis][1] from my go based application. I looked at the documentation in go [document here][2] but I am not sure how to write a simple code to do that in go. 

here is what I tried to write:

&lt;!-- begin snippet: js hide: false console: true babel: false --&gt;

&lt;!-- language: lang-js --&gt;

    package main

    import (
    	&quot;context&quot;
    	&quot;google.golang.org/api/cloudidentity/v1beta1&quot;
      )
      
     func main() {  
    	ctx := context.Background()
    	cloudidentityService, err := cloudidentity.NewService(ctx)
    	res, err := cloudidentity.groups.memberships.lookup(&#39;placeholder-value&#39;, &#39;memberKey.namespace&#39;)
     }

&lt;!-- end snippet --&gt;

On running this i get error &quot;cannot refer to unexported name cloudidentity.groups&quot;

I am new to Google cloud as well as golang. My task is to find if the user is part of a given group in google cloud.
  [1]: https://cloud.google.com/identity/docs/reference/rest/v1beta1/groups.memberships
  [2]: https://pkg.go.dev/google.golang.org/api/cloudidentity/v1beta1#GroupsMembershipsLookupCall

</details>


# 答案1
**得分**: 2

在Go语言中，如果一个名称以大写字母开头，那么它就是可导出的。这意味着你从导入的包中调用的任何方法都必须由这些包导出，并且必须以大写字母开头。这应该解决你的问题。请注意以下两者之间的区别：

- `.Groups.Memberships.Lookup`
- `.groups.memberships.lookup`

```go
package main

import (
	"context"
	"google.golang.org/api/cloudidentity/v1"
)

func main() {
	ctx := context.Background()
	svc, err := cloudidentity.NewService(ctx)
	if err != nil {
		panic(err)
	}
	res, err := svc.Groups.Memberships.Lookup("...").Context(ctx).Do()
	if err != nil {
		panic(err)
	}
	_ = res
}

希望对你有帮助！

package main

import (
	"context"
	"google.golang.org/api/cloudidentity/v1"
)

func main() {
	ctx := context.Background()
	svc, err := cloudidentity.NewService(ctx)
	if err != nil {
		panic(err)
	}
	res, err := svc.Groups.Memberships.Lookup("...").Context(ctx).Do()
	if err != nil {
		panic(err)
	}
	_ = res
}