How to list objects using C# SDK V1 - Object Storage Service

Bu konuda, bir paket içindeki tüm nesnelerin, belirli sayıda nesnenin ve adları belirli bir önek içeren nesnelerin nasıl listeleneceği açıklanmaktadır.

Notlar

Bu konuda Çin (Hangzhou) bölgesinin genel uç noktası kullanılmıştır. OSS ile aynı bölgedeki diğer Alibaba Cloud hizmetlerinden OSS'e erişmek için dahili uç nokta kullanın. OSS bölgeleri ve uç noktaları hakkında daha fazla bilgi için bkz. Bölgeler ve uç noktalar.
Bu konuda bir OSS uç noktası kullanılarak bir OSSClient örneğinin oluşturulması gösterilmektedir. Özel bir etki alanı kullanma veya Security Token Service (STS) kimlik bilgileriyle kimlik doğrulama gibi alternatif yapılandırmalar için bkz. Başlatma (C# SDK V1).
Nesneleri listelemek için oss:ListObjects iznine sahip olmanız gerekir. Daha fazla bilgi için bkz. Özel ilke atama.

Basit nesne listeleme

Aşağıdaki örnek kodda, belirtilen bir paketteki 100 nesnenin nasıl listeleneceği gösterilmektedir:

using Aliyun.OSS;
// Specify the endpoint of the region in which the bucket is located. For example, if the bucket is located in the China (Hangzhou) region, set the endpoint to https://oss-cn-hangzhou.aliyuncs.com. Specify your actual endpoint. 
var endpoint = "yourEndpoint";
// Obtain access credentials from environment variables. Before you run the sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are configured. 
var accessKeyId = Environment.GetEnvironmentVariable("OSS_ACCESS_KEY_ID");
var accessKeySecret = Environment.GetEnvironmentVariable("OSS_ACCESS_KEY_SECRET");
// Specify the name of the bucket. Example: examplebucket. 
var bucketName = "examplebucket";
// Specify the region in which the bucket is located. For example, if the bucket is located in the China (Hangzhou) region, set the region to cn-hangzhou.
const string region = "cn-hangzhou";

// Create a ClientConfiguration instance and modify the default parameters based on your requirements.
var conf = new ClientConfiguration();

// Use the signature algorithm V4.
conf.SignatureVersion = SignatureVersion.V4;

// Create an OSSClient instance.
var client = new OssClient(endpoint, accessKeyId, accessKeySecret, conf);
client.SetRegion(region);
try
{
    var listObjectsRequest = new ListObjectsRequest(bucketName);
    // List objects in the bucket using simple list. By default, 100 objects are returned. 
    var result = client.ListObjects(listObjectsRequest);
    Console.WriteLine("List objects succeeded");
    foreach (var summary in result.ObjectSummaries)
    {
        Console.WriteLine("File name:{0}", summary.Key);
    }
}
catch (Exception ex)
{
    Console.WriteLine("List objects failed. {0}", ex.Message);
}

Belirli sayıda nesneyi listeleme

Aşağıdaki örnek kodda, belirli sayıda nesnenin nasıl listeleneceği gösterilmektedir:

using Aliyun.OSS;
// Specify the endpoint of the region in which the bucket is located. For example, if the bucket is located in the China (Hangzhou) region, set the endpoint to https://oss-cn-hangzhou.aliyuncs.com. Specify your actual endpoint. 
var endpoint = "yourEndpoint";
// Obtain access credentials from environment variables. Before you run the sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are configured. 
var accessKeyId = Environment.GetEnvironmentVariable("OSS_ACCESS_KEY_ID");
var accessKeySecret = Environment.GetEnvironmentVariable("OSS_ACCESS_KEY_SECRET");
// Specify the name of the bucket. Example: examplebucket. 
var bucketName = "examplebucket";
// Specify the region in which the bucket is located. For example, if the bucket is located in the China (Hangzhou) region, set the region to cn-hangzhou.
const string region = "cn-hangzhou";

// Create a ClientConfiguration instance and modify the default parameters based on your requirements.
var conf = new ClientConfiguration();

// Use the signature algorithm V4.
conf.SignatureVersion = SignatureVersion.V4;

// Create an OSSClient instance.
var client = new OssClient(endpoint, accessKeyId, accessKeySecret, conf);
client.SetRegion(region);
try
{
    var listObjectsRequest = new ListObjectsRequest(bucketName)
    {
        // Specify MaxKeys to set the maximum number of listed objects to 200.  The default value of MaxKeys is 100. The maximum value of MaxKeys is 1000. 
        MaxKeys = 200,
    };
    var result = client.ListObjects(listObjectsRequest);
    Console.WriteLine("List objects succeeded");
    foreach (var summary in result.ObjectSummaries)
    {
        Console.WriteLine(summary.Key);
    }
}
catch (Exception ex)
{
    Console.WriteLine("List objects failed, {0}", ex.Message);
}

Adları belirtilen öneki içeren nesneleri listeleme

Aşağıdaki örnek kodda, bir pakette adları belirli bir önek içeren nesnelerin nasıl listeleneceği gösterilmektedir:

using Aliyun.OSS;
using Aliyun.OSS.Common;
// Specify the endpoint of the region in which the bucket is located. For example, if the bucket is located in the China (Hangzhou) region, set the endpoint to https://oss-cn-hangzhou.aliyuncs.com. Specify your actual endpoint. 
var endpoint = "yourEndpoint";
// Obtain access credentials from environment variables. Before you run the sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are configured. 
var accessKeyId = Environment.GetEnvironmentVariable("OSS_ACCESS_KEY_ID");
var accessKeySecret = Environment.GetEnvironmentVariable("OSS_ACCESS_KEY_SECRET");
// Specify the name of the bucket. Example: examplebucket. 
var bucketName = "examplebucket";
// List objects whose names contain the "test" prefix. By default, a maximum of 100 objects are listed. 
var prefix = "test";
// Specify the region in which the bucket is located. For example, if the bucket is located in the China (Hangzhou) region, set the region to cn-hangzhou.
const string region = "cn-hangzhou";

// Create a ClientConfiguration instance and modify the default parameters based on your requirements.
var conf = new ClientConfiguration();

// Use the signature algorithm V4.
conf.SignatureVersion = SignatureVersion.V4;

// Create an OSSClient instance.
var client = new OssClient(endpoint, accessKeyId, accessKeySecret, conf);
client.SetRegion(region);
try
{
    var keys = new List<string>();
    ObjectListing result = null;
    string nextMarker = string.Empty;
    do
    {
        var listObjectsRequest = new ListObjectsRequest(bucketName)
        {
            Marker = nextMarker,
            MaxKeys = 100,
            Prefix = prefix,
        };
        result = client.ListObjects(listObjectsRequest);
        foreach (var summary in result.ObjectSummaries)
        {
            Console.WriteLine(summary.Key);
            keys.Add(summary.Key);
        }
        nextMarker = result.NextMarker;
    } while (result.IsTruncated);
    Console.WriteLine("List objects of bucket:{0} succeeded ", bucketName);
}
catch (OssException ex)
{
    Console.WriteLine("Failed with error code: {0}; Error info: {1}. \nRequestID:{2}\tHostID:{3}",
        ex.ErrorCode, ex.Message, ex.RequestId, ex.HostId);
}
catch (Exception ex)
{
    Console.WriteLine("Failed with error info: {0}", ex.Message);
}

Adları marker değerinden sonra alfabetik sıraya göre gelen nesneleri listeleme

Listeleme işleminin başlayacağı nesnenin adını belirtmek için marker parametresini yapılandırabilirsiniz. Aşağıdaki örnek kodda, marker parametresinin değerinden sonra alfabetik sıraya göre gelen nesnelerin nasıl listeleneceği gösterilmektedir:

using Aliyun.OSS;
using Aliyun.OSS.Common;
// Specify the endpoint of the region in which the bucket is located. For example, if the bucket is located in the China (Hangzhou) region, set the endpoint to https://oss-cn-hangzhou.aliyuncs.com. Specify your actual endpoint. 
var endpoint = "yourEndpoint";
// Obtain access credentials from environment variables. Before you run the sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are configured. 
var accessKeyId = Environment.GetEnvironmentVariable("OSS_ACCESS_KEY_ID");
var accessKeySecret = Environment.GetEnvironmentVariable("OSS_ACCESS_KEY_SECRET");
// Specify the name of the bucket. Example: examplebucket. 
var bucketName = "examplebucket";
// Specify the marker parameter. Example: exampleobject.txt. 
var marker = "exampleobject.txt";
// Specify the region in which the bucket is located. For example, if the bucket is located in the China (Hangzhou) region, set the region to cn-hangzhou.
const string region = "cn-hangzhou";

// Create a ClientConfiguration instance and modify the default parameters based on your requirements.
var conf = new ClientConfiguration();

// Use the signature algorithm V4.
conf.SignatureVersion = SignatureVersion.V4;

// Create an OSSClient instance.
var client = new OssClient(endpoint, accessKeyId, accessKeySecret, conf);
client.SetRegion(region);
try
{
    var keys = new List<string>();
    ObjectListing result = null;
    string nextMarker = marker;
    do
    {
        var listObjectsRequest = new ListObjectsRequest(bucketName)
        // You can modify the value of MaxKeys to return more objects or list objects by page. 
        {
            Marker = nextMarker,
            MaxKeys = 100,
        };
        result = client.ListObjects(listObjectsRequest);
        foreach (var summary in result.ObjectSummaries)
        {
            Console.WriteLine(summary.Key);
            keys.Add(summary.Key);
        }
        nextMarker = result.NextMarker;
    // If the value of IsTruncated is true, the next read starts from NextMarker. 
    } while (result.IsTruncated);
    Console.WriteLine("List objects of bucket:{0} succeeded ", bucketName);
}
catch (OssException ex)
{
    Console.WriteLine("Failed with error code: {0}; Error info: {1}. \nRequestID:{2}\tHostID:{3}",
        ex.ErrorCode, ex.Message, ex.RequestId, ex.HostId);
}
catch (Exception ex)
{
    Console.WriteLine("Failed with error info: {0}", ex.Message);
}

Tüm dosyaları listeleme

Aşağıdaki örnek kodda, belirtilen bir paketteki tüm nesnelerin nasıl listeleneceği gösterilmektedir:

using Aliyun.OSS;
// Specify the endpoint of the region in which the bucket is located. For example, if the bucket is located in the China (Hangzhou) region, set the endpoint to https://oss-cn-hangzhou.aliyuncs.com. Specify your actual endpoint. 
var endpoint = "yourEndpoint";
// Obtain access credentials from environment variables. Before you run the sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are configured. 
var accessKeyId = Environment.GetEnvironmentVariable("OSS_ACCESS_KEY_ID");
var accessKeySecret = Environment.GetEnvironmentVariable("OSS_ACCESS_KEY_SECRET");
// Specify the name of the bucket. Example: examplebucket. 
var bucketName = "examplebucket";
// Specify the region in which the bucket is located. For example, if the bucket is located in the China (Hangzhou) region, set the region to cn-hangzhou.
const string region = "cn-hangzhou";

// Create a ClientConfiguration instance and modify the default parameters based on your requirements.
var conf = new ClientConfiguration();

// Use the signature algorithm V4.
conf.SignatureVersion = SignatureVersion.V4;

// Create an OSSClient instance.
var client = new OssClient(endpoint, accessKeyId, accessKeySecret, conf);
client.SetRegion(region);
// List all objects in the bucket. 
public void ListObject(string bucketName)
{
    try
    {
        ObjectListing result = null; 
        string nextMarker = string.Empty;
        do
        {
            // You can configure the MaxKeys parameter to specify the maximum number of objects that can be listed on each page. If the number of returned objects exceeds the value of MaxKeys, the objects are listed by page. 
            var listObjectsRequest = new ListObjectsRequest(bucketName)
            {
                Marker = nextMarker,
                MaxKeys = 100
            };
            result = client.ListObjects(listObjectsRequest);  
            Console.WriteLine("File:");
            foreach (var summary in result.ObjectSummaries)
            {
                Console.WriteLine("Name:{0}", summary.Key);
            }
            nextMarker = result.NextMarker;
        } while (result.IsTruncated);
    }
    catch (Exception ex)
    {
        Console.WriteLine("List object failed. {0}", ex.Message);
    }
}

Bir paketteki nesneleri eşzamansız olarak listeleme

Aşağıdaki örnek kodda, belirtilen bir paketteki nesnelerin eşzamansız olarak nasıl listeleneceği gösterilmektedir:

using System;
using System.IO;
using System.Threading;
using Aliyun.OSS;
namespace AsyncListObjects
{
    class Program
    {   
        // Specify the endpoint of the region in which the bucket is located. For example, if the bucket is located in the China (Hangzhou) region, set the endpoint to https://oss-cn-hangzhou.aliyuncs.com. Specify your actual endpoint. 
        static string endpoint = "yourEndpoint";
        // Obtain access credentials from environment variables. Before you run the sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are configured. 
        var accessKeyId = Environment.GetEnvironmentVariable("OSS_ACCESS_KEY_ID");
        var accessKeySecret = Environment.GetEnvironmentVariable("OSS_ACCESS_KEY_SECRET");
        // Specify the name of the bucket. Example: examplebucket. 
        static string bucketName = "yourBucketName";
        static AutoResetEvent _event = new AutoResetEvent(false);
        // Specify the region in which the bucket is located. For example, if the bucket is located in the China (Hangzhou) region, set the region to cn-hangzhou.
        const string region = "cn-hangzhou";
        
        // Create a ClientConfiguration instance and modify the default parameters based on your requirements.
        var conf = new ClientConfiguration();
        
        // Use the signature algorithm V4.
        conf.SignatureVersion = SignatureVersion.V4;
        
        // Create an OSSClient instance.
        var client = new OssClient(endpoint, accessKeyId, accessKeySecret, conf);
        client.SetRegion(region);
        static void Main(string[] args)
        {
            Program.AsyncListObjects();
            Console.ReadKey();
        }
        public static void AsyncListObjects()
        {
            try
            {
                var listObjectsRequest = new ListObjectsRequest(bucketName);
                client.BeginListObjects(listObjectsRequest, ListObjectCallback, null);
                _event.WaitOne();
            }
            catch (Exception ex)
            {
                Console.WriteLine("Async list objects failed. {0}", ex.Message);
            }
        }
        // Call the ListObjectCallback method to implement callback after the objects are asynchronously listed. If you call asynchronous operations to list objects, the operations must implement callback in similar methods. 
        private static void ListObjectCallback(IAsyncResult ar)
        {
            try
            {
                var result = client.EndListObjects(ar);
                foreach (var summary in result.ObjectSummaries)
                {
                    Console.WriteLine("Object name: {0}", summary.Key);
                }
                _event.Set();
                Console.WriteLine("Async list objects succeeded");
            }
            catch (Exception ex)
            {
                Console.WriteLine("Async list objects failed. {0}", ex.Message);
            }
        }
    }
}

İlgili kaynaklar

Nesneleri eşzamanlı olarak listelemek için kullanılan tam örnek kodu görüntülemek üzere GitHub adresini ziyaret edin.
Nesneleri eşzamansız olarak listelemek için kullanılan tam örnek kodu görüntülemek üzere GitHub adresini ziyaret edin.
Nesneleri listelemek için çağırabileceğiniz API işlemi hakkında daha fazla bilgi için bkz. GetBucket (ListObjects).