/// 下载对象
public void GetObject()
{
//.cssg-snippet-body-start:[get-object]
try
{
string bucket = "examplebucket-1250000000"; //存储桶，格式：BucketName-APPID
string key = "exampleobject"; //对象键
string localDir = System.IO.Path.GetTempPath(); //本地文件夹
string localFileName = "my-local-temp-file"; //指定本地保存的文件名
GetObjectRequest request = new GetObjectRequest(bucket, key, localDir, localFileName);
//设置进度回调
request.SetCosProgressCallback(delegate(long completed, long total)
{
Console.WriteLine(String.Format("progress = {0:##.##}%", completed * 100.0 / total));
});
//执行请求
GetObjectResult result = cosXml.GetObject(request);
//请求成功
Console.WriteLine(result.GetResultInfo());
}
catch (COSXML.CosException.CosClientException clientEx)
{
//请求失败
Console.WriteLine("CosClientException: " + clientEx);
}
catch (COSXML.CosException.CosServerException serverEx)
{
//请求失败
Console.WriteLine("CosServerException: " + serverEx.GetInfo());
}
//.cssg-snippet-body-end
}
public async Task GetObjectAsync(string bucketName, string objectName, Action <Stream> callback, CancellationToken cancellationToken = default)
{
if (string.IsNullOrEmpty(bucketName))
{
throw new ArgumentNullException(nameof(bucketName));
}
if (string.IsNullOrEmpty(objectName))
{
throw new ArgumentNullException(nameof(objectName));
}
if (!await ObjectsExistsAsync(bucketName, objectName))
{
throw new Exception($"Object '{objectName}' not in bucket '{bucketName}'");
}
bucketName = ConvertBucketName(bucketName);
await Task.Run(() =>
{
GetObjectBytesRequest request = new GetObjectBytesRequest(bucketName, objectName);
//执行请求
GetObjectBytesResult result = _client.GetObject(request);
//获取内容
byte[] content = result.content;
if (content != null && content.Length > 0)
{
MemoryStream ms = new MemoryStream(content);
callback(ms);
}
else
{
throw new Exception("Get object bytes is null.");
}
}, cancellationToken);
}
public void Get(string remotename, Stream stream)
{
try
{
cosXml = GetCosXml();
string bucket = _cosOptions.Bucket;
string key = GetFullKey(remotename);
GetObjectBytesRequest request = new GetObjectBytesRequest(bucket, key);
request.SetSign(TimeUtils.GetCurrentTime(TimeUnit.SECONDS), KEY_DURATION_SECOND);
GetObjectBytesResult result = cosXml.GetObject(request);
byte[] bytes = result.content;
Stream ms = new MemoryStream(bytes);
Utility.Utility.CopyStream(ms, stream);
}
catch (COSXML.CosException.CosClientException clientEx)
{
Logging.Log.WriteErrorMessage(LOGTAG, "Get", clientEx, "Get failed: {0}", remotename);
throw;
}
catch (COSXML.CosException.CosServerException serverEx)
{
Logging.Log.WriteErrorMessage(LOGTAG, "Get", serverEx, "Get failed: {0}, {1}", remotename, serverEx.GetInfo());
throw;
}
}
/// 下载时添加盲水印
public void DownloadObjectWithWatermark()
{
string bucket = "examplebucket-1250000000"; //存储桶，格式：BucketName-APPID
string key = "exampleobject"; //对象键
string localDir = System.IO.Path.GetTempPath(); //本地文件夹
string localFileName = "my-local-temp-file"; //指定本地保存的文件名
//.cssg-snippet-body-start:[download-object-with-watermark]
GetObjectRequest getObjectRequest = new GetObjectRequest(bucket, key, localDir, localFileName);
//处理参数，规则参见：https://cloud.tencent.com/document/product/460/19017
getObjectRequest.SetQueryParameter("watermark/3/type/<type>/image/<imageUrl>/text/<text>", null);
GetObjectResult result = cosXml.GetObject(getObjectRequest);
//.cssg-snippet-body-end
}
/// 获取预签名下载链接
public void GetPresignDownloadUrl()
{
//.cssg-snippet-body-start:[get-presign-download-url]
try
{
PreSignatureStruct preSignatureStruct = new PreSignatureStruct();
preSignatureStruct.appid = "1250000000"; //腾讯云账号 APPID
preSignatureStruct.region = "COS_REGION"; //存储桶地域
preSignatureStruct.bucket = "examplebucket-1250000000"; //存储桶
preSignatureStruct.key = "exampleobject"; //对象键
preSignatureStruct.httpMethod = "GET"; //HTTP 请求方法
preSignatureStruct.isHttps = true; //生成 HTTPS 请求 URL
preSignatureStruct.signDurationSecond = 600; //请求签名时间为600s
preSignatureStruct.headers = null; //签名中需要校验的 header
preSignatureStruct.queryParameters = null; //签名中需要校验的 URL 中请求参数
string requestSignURL = cosXml.GenerateSignURL(preSignatureStruct);
//下载请求预签名 URL (使用永久密钥方式计算的签名 URL)
string localDir = System.IO.Path.GetTempPath(); //本地文件夹
string localFileName = "my-local-temp-file"; //指定本地保存的文件名
GetObjectRequest request = new GetObjectRequest(null, null, localDir, localFileName);
//设置下载请求预签名 URL
request.RequestURLWithSign = requestSignURL;
//设置进度回调
request.SetCosProgressCallback(delegate(long completed, long total)
{
Console.WriteLine(String.Format("progress = {0:##.##}%", completed * 100.0 / total));
});
//执行请求
GetObjectResult result = cosXml.GetObject(request);
//请求成功
Console.WriteLine(result.GetResultInfo());
}
catch (COSXML.CosException.CosClientException clientEx)
{
//请求失败
Console.WriteLine("CosClientException: " + clientEx);
}
catch (COSXML.CosException.CosServerException serverEx)
{
//请求失败
Console.WriteLine("CosServerException: " + serverEx.GetInfo());
}
//.cssg-snippet-body-end
}