如何除錯我的GolangAPI代碼以顯示出了什么問題？

我有這個模塊，它使用 Google Cloud API 檢索特定專案的所有正在運行的虛擬機實體的串列。我是 Go 的新手，并按照介紹教程來幫助我。我仍在嘗試除錯我的代碼，但沒有運氣。

問題是我能夠與 Google Cloud API 通信并通過身份驗證，但這就是我所能通過的

compute.go 模塊：

compute.go 能夠與 Google Cloud 服務器通信并通過身份驗證（我沒有收到身份驗證錯誤）

// Copyright 2021 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package compute

// [START compute_instances_list_all]
import (
    "context"
    "fmt"
    "io"

    compute "cloud.google.com/go/compute/apiv1"
    "google.golang.org/api/iterator"
    computepb "google.golang.org/genproto/googleapis/cloud/compute/v1"
    "google.golang.org/protobuf/proto"
)

// listAllInstances prints all instances present in a project, grouped by their zone.
func ListAllInstances(w io.Writer, projectID string) error {
    // projectID := "your_project_id"
    ctx := context.Background()
    instancesClient, err := compute.NewInstancesRESTClient(ctx)
    // instancesClient, err := compute.NewInstancesRESTClient(ctx, option.WithCredentialsFile(`C:\path\to\jsonkey.json`))

    if err != nil {
        return fmt.Errorf("NewInstancesRESTClient: %v", err)
    }
    defer instancesClient.Close()

    // Use the `MaxResults` parameter to limit the number of results that the API returns per response page.
    req := &computepb.AggregatedListInstancesRequest{
        Project:    projectID,
        MaxResults: proto.Uint32(6),
    }

    it := instancesClient.AggregatedList(ctx, req)
    fmt.Fprintf(w, "Instances found:\n")
    // Despite using the `MaxResults` parameter, you don't need to handle the pagination
    // yourself. The returned iterator object handles pagination
    // automatically, returning separated pages as you iterate over the results.
    for {
        pair, err := it.Next()
        if err == iterator.Done {
            break
        }
        if err != nil {
            return err
        }
        instances := pair.Value.Instances
        if len(instances) > 0 {
            fmt.Fprintf(w, "%s\n", pair.Key)
            for _, instance := range instances {
                fmt.Fprintf(w, "- %s %s\n", instance.GetName(), instance.GetMachineType())
            }
        }
    }

    return nil
}

// [END compute_instances_list_all]

但是問題是當我運行呼叫 的主函式時ListAllInstances，它回傳一個<nil>. 不允許我知道哪里出了問題。

我運行的呼叫者 api.go 模塊go run .：

package main

import (
    "fmt"

    "example.com/compute"

    "bytes"
)

func main() {
    buf := new(bytes.Buffer)

    // Get a message and print it.
    respone := compute.ListAllInstances(buf, "project-unique-id")
    fmt.Println(respone)
}

我還能如何進一步除錯以找出我的代碼有什么問題？

uj5u.com熱心網友回復：

你不是在列印buf。您的函式回傳一個型別為 的物件error，即nil（沒有錯誤！），實際輸出將寫入buf.

要么列印出來：

func main() {
    buf := new(bytes.Buffer)

    // Get a message and print it.
    err := compute.ListAllInstances(buf, "project-unique-id")
    if err != nil {
        panic(err)
    }
    fmt.Println(buf.String())  // <======= Print buf contents!
}

或者只是使用os.Stdout：

func main() {

    err := compute.ListAllInstances(os.Stdout, "project-unique-id")

    if err != nil {
        panic(err)
    }

}

要回答有關除錯的問題，請嘗試將 VSCode 與Go 擴展一起使用，在那里您可以運行除錯器、設定斷點并逐行執行代碼，觀察變數如何變化。

另請參閱在 VS Code 中除錯 Go 程式。

標籤：走

上一篇：奇怪的方法輸出

下一篇：離子電容器iOS不尊重暗模式