# 复制多版本对象
您可以通过OBSCopyObjectRequest接口传入版本号（versionID）来复制多版本对象，示例代码如下：
```
static OBSClient *client;
NSString *endPoint = @"https://your-endpoint";
// 认证用的ak和sk硬编码到代码中或者明文存储都有很大的安全风险，建议在配置文件或者环境变量中密文存放，使用时解密，确保安全；本示例以ak和sk保存在环境变量中为例，运行本示例前请先在本地环境中设置环境变量AccessKeyID和SecretAccessKey。
// 您可以登录访问管理控制台获取访问密钥AK/SK，获取方式请参见https://support.huaweicloud.com/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];
    
// 初始化身份验证
OBSStaticCredentialProvider *credentialProvider = [[OBSStaticCredentialProvider alloc] initWithAccessKey:AK secretKey:SK];
    
//初始化服务配置
OBSServiceConfiguration *conf = [[OBSServiceConfiguration alloc] initWithURLString:endPoint credentialProvider:credentialProvider];
    
// 初始化client
client = [[OBSClient alloc] initWithConfiguration:conf];
    
OBSCopyObjectRequest *request = [[OBSCopyObjectRequest alloc]initWithSrcBucketName:@"source-bucketname" srcObjectKey:@"objectname1" dstBucketName:@"destination-bucketname" dstObjectKey:@"objectname2"];
    
// 被拷贝对象多版本ID
request.srcObjectVersionID = @"testVersionID";
[client copyObject:request completionHandler:^(OBSCopyObjectResponse *response, NSError *error){
    NSLog(@"%@",response);
}] ;
```
![](https://support.huaweicloud.com/sdk-ios-devg-obs/public_sys-resources/note_3.0-zh-cn.png)
- 复制多版本对象过程中返回的错误码含义、问题原因及处理措施可参考[OBS错误码](https://support.huaweicloud.com/sdk-ios-devg-obs/obs_27_1601.html)、[sdk自定义异常](https://support.huaweicloud.com/sdk-ios-devg-obs/obs_27_1604.html)、[sdk公共响应头](https://support.huaweicloud.com/sdk-ios-devg-obs/obs_27_1602.html)。