Azure Blob，缓存json文件不起作用

有人对Windows azure上的缓存控制有一些经验吗。我就是不能让它工作。我有一个JSON文件，我想要一些缓存规则

            var matchContainer = _blobClient.GetContainerReference(match.ClassContainer);
            matchContainer.CreateIfNotExists();
            matchContainer.SetPermissions(new BlobContainerPermissions
                                            {
                                                PublicAccess = BlobContainerPublicAccessType.Blob
                                            });
            // save the blob into the blob service   
            string uniqueBlobName = string.Format("matchdata/" + match.KeyPath + ".json").ToLower();
            CloudBlockBlob blob = matchContainer.GetBlockBlobReference(uniqueBlobName);
            var matchString = match.ToString();
            MemoryStream stream = new MemoryStream();
            StreamWriter writer = new StreamWriter(stream);
            writer.AutoFlush = true;
            writer.Write(matchString);
            stream.Seek(0, SeekOrigin.Begin);
            blob.UploadFromStream(stream);
            blob.Properties.CacheControl = "max-age=3600, must-revalidate";
            blob.SetProperties();

这和这里的样品完全一样设置缓存控制示例

只是没有设置好标题。希望你能帮忙。