Obtaining a Versioning Object

You can call a subclass of OBSAbstractGetObjectRequest and set request.versionID to obtain an object version.

Sample code is as follows:

static OBSClient *client;
NSString *endPoint = @"https://your-endpoint";
// Hard-coded or plaintext AK and SK are risky. For security purposes, encrypt your AK and SK before storing them in the configuration file or environment variables. In this example, the AK and SK are stored in environment variables. Before running the code in this example, configure environment variables AccessKeyID and SecretAccessKey.
// Obtain an AK/SK pair on the management console. For details, see https://support.huaweicloud.com/intl/en-us/usermanual-ca/ca_01_0003.html.
char* ak_env = getenv("AccessKeyID");
char* sk_env = getenv("SecretAccessKey");
if (ak_env == NULL || sk_env == NULL) {
    NSLog(@"Error: AccessKeyID or SecretAccessKey environment variable not set");
    return;
}
NSString *AK = [NSString stringWithUTF8String:ak_env];
NSString *SK = [NSString stringWithUTF8String:sk_env];
    
// Initialize identity authentication.
OBSStaticCredentialProvider *credentialProvider = [[OBSStaticCredentialProvider alloc] initWithAccessKey:AK secretKey:SK];
    
//Initialize service configuration.
OBSServiceConfiguration *conf = [[OBSServiceConfiguration alloc] initWithURLString:endPoint credentialProvider:credentialProvider];
    
// Initialize an instance of OBSClient.
client = [[OBSClient alloc] initWithConfiguration:conf];
    
// Obtain versioning objects.
OBSGetObjectToDataRequest *request = [[OBSGetObjectToDataRequest alloc]initWithBucketName:@"bucketname" objectKey:@"objectname"];
    
// Query the version ID of the versioning object.
request.versionID = @"";
    
//Query the download progress.
request.downloadProgressBlock = ^(int64_t bytesWritten, int64_t totalBytesWritten, int64_t totalBytesExpectedToWrite) {
    NSLog(@"%0.1f%%", (totalBytesExpectedToWrite > 0) ? (float)(totalBytesWritten)*100/(float)totalBytesExpectedToWrite : 0);
};
// Receive downloaded data.
__block NSMutableData *objectData = [NSMutableData new];
request.onReceiveDataBlock = ^(NSData *data) {
    [objectData appendData:data];
};
    
[ client getObject:request completionHandler:^(OBSGetObjectResponse *response, NSError *error){
    NSLog(@"%@",response);
}] ;

• If the version ID is null, the object of the latest version will be downloaded, by default.