Overview

This document provides an overview of APIs and SDK code samples related to listing objects.

SDK API Reference

For the parameters and method descriptions of all the APIs in the SDK, please see SDK API Reference.

Querying an Object List

API description

This API is used to query some or all objects in a bucket.

Sample 1. Requesting the first page of objects

try
{
  string bucket = "examplebucket-1250000000"; // Format: BucketName-APPID
  GetBucketRequest request = new GetBucketRequest(bucket);
  // Execute the request
  GetBucketResult result = cosXml.GetBucket(request);
  // Bucket information
  ListBucket info = result.listBucket;
  if (info.isTruncated) {
    // Record the marker for the next page of truncated listing
    this.nextMarker = info.nextMarker;
  }
}
catch (COSXML.CosException.CosClientException clientEx)
{
  // Request failed
  Console.WriteLine("CosClientException: " + clientEx);
}
catch (COSXML.CosException.CosServerException serverEx)
{
  // Request failed
  Console.WriteLine("CosServerException: " + serverEx.GetInfo());
}

Note：

For the complete sample, go to GitHub.

Sample 2. Requesting the next page of objects

try
{
  string bucket = "examplebucket-1250000000"; // Format: BucketName-APPID
  GetBucketRequest request = new GetBucketRequest(bucket);
  // Use the “nextMarker” from the previous request
  request.SetMarker(this.nextMarker);
  // Execute the request
  GetBucketResult result = cosXml.GetBucket(request);
  // Bucket information
  ListBucket info = result.listBucket;
}
catch (COSXML.CosException.CosClientException clientEx)
{
  // Request failed
  Console.WriteLine("CosClientException: " + clientEx);
}
catch (COSXML.CosException.CosServerException serverEx)
{
  // Request failed
  Console.WriteLine("CosServerException: " + serverEx.GetInfo());
}

Note：

For the complete sample, go to GitHub.

Sample 3. Getting an object list and common prefixes

try
{
  string bucket = "examplebucket-1250000000"; // Format: BucketName-APPID
  GetBucketRequest request = new GetBucketRequest(bucket);
  // List objects and common prefixes under a/
  request.SetPrefix("a/");
  // Execute the request
  GetBucketResult result = cosXml.GetBucket(request);
  // Bucket information
  ListBucket info = result.listBucket;
  // List objects
  List<ListBucket.Contents> objects = info.contentsList;
  // List common prefixes
  List<ListBucket.CommonPrefixes> subDirs = info.commonPrefixesList;
}
catch (COSXML.CosException.CosClientException clientEx)
{
  // Request failed
  Console.WriteLine("CosClientException: " + clientEx);
}
catch (COSXML.CosException.CosServerException serverEx)
{
  // Request failed
  Console.WriteLine("CosServerException: " + serverEx.GetInfo());
}

Note：

For the complete sample, go to GitHub.

Querying an Object Version List

API description

This API is used to query some or all objects in a versioning-enabled bucket.

Sample 1. Requesting the first page of listed object versions

try
{
  string bucket = "examplebucket-1250000000"; // Format: BucketName-APPID
  ListBucketVersionsRequest request = new ListBucketVersionsRequest(bucket);
  // Execute the request
  ListBucketVersionsResult result = cosXml.ListBucketVersions(request);
  // Bucket information
  ListBucketVersions info = result.listBucketVersions;

  List<ListBucketVersions.ObjectVersion> objects = info.objectVersionList;
  List<ListBucketVersions.CommonPrefixes> prefixes = info.commonPrefixesList;

  if (info.isTruncated) {
    // Record the marker for the next page of truncated listing
    this.keyMarker = info.nextKeyMarker;
    this.versionIdMarker = info.nextVersionIdMarker;
  }
}
catch (COSXML.CosException.CosClientException clientEx)
{
  // Request failed
  Console.WriteLine("CosClientException: " + clientEx);
}
catch (COSXML.CosException.CosServerException serverEx)
{
  // Request failed
  Console.WriteLine("CosServerException: " + serverEx.GetInfo());
}

Note：

For the complete sample, go to GitHub.

Sample 2. Requesting the next page of listed object versions

try
{
  string bucket = "examplebucket-1250000000"; // Format: BucketName-APPID
  ListBucketVersionsRequest request = new ListBucketVersionsRequest(bucket);

  // Use the “nextMarker” from the previous request
  request.SetKeyMarker(this.keyMarker);
  request.SetVersionIdMarker(this.versionIdMarker);

  // Execute the request
  ListBucketVersionsResult result = cosXml.ListBucketVersions(request);
  ListBucketVersions info = result.listBucketVersions;

  if (info.isTruncated) {
    // Record the marker for the next page of truncated listing
    this.keyMarker = info.nextKeyMarker;
    this.versionIdMarker = info.nextVersionIdMarker;
  }
}
catch (COSXML.CosException.CosClientException clientEx)
{
  // Request failed
  Console.WriteLine("CosClientException: " + clientEx);
}
catch (COSXML.CosException.CosServerException serverEx)
{
  // Request failed
  Console.WriteLine("CosServerException: " + serverEx.GetInfo());
}

Note：

For the complete sample, go to GitHub.