无法使用.Net API读取Amazon S3 Object元数据，我做错了什么？

Question

I've read the S3 documentation several times and I'm adding metadata to an S3 object with this code...

PutObjectRequest titledRequest = new PutObjectRequest();
titledRequest.WithTimeout(3600000)
.WithMetaData("outputfolder", outputFolder)
.WithBucketName(AWS_BUCKET_NAME)
.WithKey(objectKey)
.WithAutoCloseStream(true)
.WithInputStream(fs);

When reading the object from the S3 bucket I'm using this code....

string outputFolder = response.Metadata["x-amz-meta-outputfolder"];

But I'm getting an empty string every time even though the outputFolder variable definitely has a value.

Am I doing something really silly wrong here? As far as I can tell this is consistent with the documentation

Answer 1

string outputFolder = response.Metadata["outputfolder"];

会做。

Answer 2

Codes verified to work.

// upload & add outputfolder to metadata

var S3Client = new AmazonS3Client();

var Request = new PutObjectRequest {
                  BucketName = bucketname,Key = S3Name,FilePath = Filepath };

Request.Metadata.Add("outputfolder",@"C:\test");

PutObjectResponse Response = S3Client.PutObject(Request);

// download and retrieve metadata

var S3Client = new AmazonS3Client();

var Request = new GetObjectRequest { BucketName = bucketname,Key = S3Name };

GetObjectResponse Response = S3Client.GetObject(Request);

// this works

string outputFolder = Response.Metadata["x-amz-meta-outputfolder"];

// so does this - no need for the x-amz-meta- prefix

string outputFolder = Response.Metadata["outputfolder"];

Answer 3

use this instead of reading the meta from putobject response

GetObjectMetadataRequest request = new GetObjectMetadataRequest()
                    .WithKey("Key")
                    .WithBucketName("");
GetObjectMetadataResponse response = s3Client.GetObjectMetaData(request);
response."choose properety to retrieve"

hope this may help