QCloudHeadObjectRequest* headerRequest = [QCloudHeadObjectRequest new];

// Object key, i.e., the full path of a COS object. If the object is in a directory, the path should be "video/xxx/movie.mp4"
headerRequest.object = @"exampleobject";

// versionId specifies the version ID of an object to query (if versioning is enabled). If versionId is not specified, the latest version will be queried.
headerRequest.versionID = @"versionID";

// Bucket name in the format of BucketName-APPID, which can be viewed in the COS console at https://console.cloud.tencent.com/cos5/bucket
headerRequest.bucket = @"examplebucket-1250000000";

[headerRequest setFinishBlock:^(NSDictionary* result, NSError *error) {
    // Detailed information returned in the result
    // Obtain file CRC64
     NSString * crc64 = [[outputObject __originHTTPURLResponse__].allHeaderFields valueForKey:@"x-cos-hash-crc64ecma"];
}];

[[QCloudCOSXMLService defaultCOSXML] HeadObject:headerRequest];

let headObject = QCloudHeadObjectRequest.init();

// Bucket name in the format of BucketName-APPID, which can be viewed in the COS console at https://console.cloud.tencent.com/cos5/bucket
headObject.bucket = "examplebucket-1250000000";

// versionId specifies the version ID of an object to query (if versioning is enabled). If versionId is not specified, the latest version will be queried.
headObject.versionID = "versionID";

// Object key, i.e., the full path of a COS object. If the object is in a directory, the path should be "video/xxx/movie.mp4"
headObject.object  = "exampleobject";
headObject.finishBlock =  {(result,error) in
    if let result = result {
        // Obtain file CRC64
        let crc64 = result?.__originHTTPURLResponse__.allHeaderFields["x-cos-hash-crc64ecma"];

    } else {
        print(error!);
    }
}
QCloudCOSXMLService.defaultCOSXML().headObject(headObject);