You can configure a progress bar to display the progress of an upload or download task.

Usage notes

  • In this topic, the public endpoint of the China (Hangzhou) region is used. If you want to access OSS by using other Alibaba Cloud services in the same region as OSS, use an internal endpoint For more information about the regions and endpoints supported by OSS, see Regions and endpoints.
  • In this topic, an OSSClient instance is created by using an OSS endpoint. If you want to create an OSSClient instance by using custom domain names or STS, see Create an OSSClient instance.

Sample code

The following code provides an example on how to use the progress bar:
#include <alibabacloud/oss/OssClient.h>
using namespace AlibabaCloud::OSS;

void ProgressCallback(size_t increment, int64_t transfered, int64_t total, void* userData)
    std::cout << "ProgressCallback[" << userData << "] => " <<
                 increment <<" ," << transfered << "," << total << std::endl;

int main(void )
    /* Initialize the information about the account that is used to access OSS. */
    /* The AccessKey pair of an Alibaba Cloud account has permissions on all API operations. Using these credentials to perform operations in OSS is a high-risk operation. We recommend that you use a RAM user to call API operations or perform routine O&M. To create a RAM user, log on to the RAM console. */
    std::string AccessKeyId = "yourAccessKeyId";
    std::string AccessKeySecret = "yourAccessKeySecret";
    /* 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 */
    std::string Endpoint = "";
    /* Specify the name of the bucket. Example: examplebucket. */
    std::string BucketName = "examplebucket";
    /* Specify the full path of the object. Do not include the bucket name in the full path. Example: exampledir/exampleobject.txt. */
    std::string ObjectName = "exampledir/exampleobject.txt";

    /* Initialize resources, such as network resources. */

    ClientConfiguration conf;
    OssClient client(Endpoint, AccessKeyId, AccessKeyS ecre t, conf);
    /* Query the object. */
    GetObjectRequest request(BucketName, ObjectName);
    TransferProgress progressCallback = { ProgressCallback , nullptr };

    auto outcome = client.GetObject(request);

    if (!outcome.isSuccess()) {    
        /* Handle exceptions. */
        std::cout << "getObject fail" <<
        ",code:" << outcome.error().Code() <<
        ",message:" << outcome.error().Message() <<
        ",requestId:" << outcome.error().RequestId() << std::endl;
         return -1;  

    /* Release resources, such as network resources. */
    return 0;


For the complete sample code on how to configure progress bars in object download, visit GitHub.