Question

我正在使用Azure开发Asp.Net MVC应用程序。当我将PDF文档上传到Azure blob存储时，它将使用下面的代码完美上传。

           var filename = Document.FileName;
           var contenttype = Document.ContentType;

           int pdfocument = Request.ContentLength;

        //uploading document in to azure blob

         CloudStorageAccount storageAccount = CloudStorageAccount.Parse(CloudConfigurationManager.GetSetting("StorageConnectionString"));

           var storageAccount = CloudStorageAccount.DevelopmentStorageAccount(FromConfigurationSetting("Connection"));
            CloudBlobClient blobClient = storageAccount.CreateCloudBlobClient();
           CloudBlobContainer container = blobClient.GetContainerReference("containername");
           container.CreateIfNotExists();
            var permissions = container.GetPermissions();
            permissions.PublicAccess = BlobContainerPublicAccessType.Blob;
            container.SetPermissions(permissions);
            string uniqueBlobName = string.Format(filename );
            CloudBlockBlob blob = container.GetBlockBlobReference(uniqueBlobName);
            blob.Properties.ContentType = ;
            blob.UploadFromStream(Request.InputStream);

将文档上传到blob后尝试阅读pdf文档时收到错误“未找到PDF标题签名”。那个erorr代码是

          byte[] pdf = new byte[pdfocument];
          HttpContext.Request.InputStream.Read(pdf, 0, pdfocument);               
          PdfReader pdfReader = new PdfReader(pdf);     //error getting here

还有一件事我忘记了，即如果我们评论上面的代码（将文档上传到Azure blob中），那么我没有收到该错误。

Answer 1

在组合使用案例中，您尝试读取Request.InputStream两次，一次是在上传期间，一次是在尝试将其读入您的byte[] pdf时 - 当您首先阅读它时，您会将其读取直至结束，所以第二次阅读很可能根本没有获得任何数据。

当你打算将PDF读入内存（前面提到的byte[] pdf）时，你可以在你的组合用例中

首先将数据读入该数组

int pdfocument = Request.ContentLength;
byte[] pdf = new byte[pdfocument];
HttpContext.Request.InputStream.Read(pdf, 0, pdfocument);

然后使用CloudBlob.UploadByteArray

上传该数组

var storageAccount = CloudStorageAccount.DevelopmentStorageAccount(FromConfigurationSetting("Connection"));
[...]
CloudBlockBlob blob = container.GetBlockBlobReference(uniqueBlobName);
blob.Properties.ContentType = ; // <--- something missing in your code...
blob.UploadByteArray(pdf);      // <--- upload byte[] instead of stream

然后提供PDF阅读器

PdfReader pdfReader = new PdfReader(pdf);

这样你只能读一次流，而byte []应该可以重复使用......

PDF标题签名未找到错误？

1 个答案: