Performing an Asynchronous Download

Updated on 2023-11-09 GMT+08:00

View PDF

You can call ObsClient.BeginGetObject and ObsClient.EndGetObject to download an object in asynchronous mode. Sample code is as follows:

// Initialize configuration parameters.
ObsConfig config = new ObsConfig();
config.Endpoint = "https://your-endpoint";
// Hard-coded or plaintext AK/SK are risky. For security purposes, encrypt your AK/SK and store them in the configuration file or environment variables. In this example, the AK/SK are stored in environment variables for identity authentication. Before running this example, configure environment variables AccessKeyID and SecretAccessKey.
// Obtain an AK/SK pair on the management console. For details, see https://support.huaweicloud.com/eu/usermanual-ca/ca_01_0003.html.
string accessKey= Environment.GetEnvironmentVariable("AccessKeyID", EnvironmentVariableTarget.Machine);
string secretKey= Environment.GetEnvironmentVariable("SecretAccessKey", EnvironmentVariableTarget.Machine);
// Create an instance of ObsClient.
ObsClient client = new ObsClient(accessKey, secretKey, config);
// Download an object in asynchronous mode.
try
{
    GetObjectRequest request = new GetObjectRequest()
    {
        BucketName = "bucketname",
        ObjectKey = "objectname",
    };
    client.BeginGetObject(request, delegate(IAsyncResult ar){
        try
        {
            using (GetObjectResponse response = client.EndGetObject(ar))
            {
                string dest = "savepath";
                if (!File.Exists(dest))
                {
                    // Write the data streams into the file.
                    response.WriteResponseStreamToFile(dest);
                }
                Console.WriteLine("Get object response: {0}", response.StatusCode);
             }
        }
        catch (ObsException ex)
        {
            Console.WriteLine("ErrorCode: {0}", ex.ErrorCode);
            Console.WriteLine("ErrorMessage: {0}", ex.ErrorMessage);
        }
    }, null);
    
}
catch (ObsException ex)
{
   Console.WriteLine("Message: {0}", ex.Message);
}