Azure Logic App Store Excel 电子邮件附件到 Blob，下载并阅读

Question

我已经设置了一个 azure logic 应用程序来侦听具有特定标题的电子邮件。该电子邮件有一个 excel 附件。当电子邮件到达时，它会将附件推送到 Azure blob 并将消息放在 queue.

上

然后我有一个函数应用程序侦听该消息并尝试处理该文件。

我有以下代码将 blob 下载为流：

BlobContainerClient containerClient = _blobServiceClient.GetBlobContainerClient(containerName);
BlobClient blobClient = containerClient.GetBlobClient(fileName);
BlobDownloadInfo download = await blobClient.DownloadAsync();
using Stream downloadFileStream = new MemoryStream();
await download.Content.CopyToAsync(downloadFileStream);
downloadFileStream.Position = 0;

然后我将其转换为如下所示的 Azure blob object：

public class AzureBlob
{
    public string Id { get; set; }
    public string Name { get; set; }
    public string ContentBytes { get; set; }
    public string ContentType { get; set; }
    public int Size { get; set; }
    public bool IsInline { get; set; }
    public DateTime LastModifiedDateTime { get; set; }
    public string ContentId { get; set; }
}

使用此代码：

StreamReader reader = new StreamReader(downloadFileStream);
string fileContents = reader.ReadToEnd();
AzureBlob blob = JsonSerializer.Deserialize<AzureBlob>(fileContents);

然后我尝试像这样用 OpenXML 打开它：

（“ContentType”返回为“application/vnd。openxmlformats-officedocument。spreadsheetml.sheet”）

Stream stockFileStream = new MemoryStream(Encoding.Unicode.GetBytes(blob.ContentBytes));
SpreadsheetDocument spreadsheetDocument = SpreadsheetDocument.Open(stockFileStream, true);

但我得到以下错误：

System.IO.FileFormatException: File contains corrupted data.

谁能帮我找出我做错了什么？

Answer 1

我发现blob.ContentBytes是一个base64字符串，你需要用Convert.FromBase64String把它转换成bytes[]。

Stream stockFileStream = new MemoryStream(Convert.FromBase64String(blob.ContentBytes));

Answer 2

通过稍微改变 class 使其工作：

public class AzureBlob
{
    public string Id { get; set; }
    public string Name { get; set; }
    public byte[] ContentBytes { get; set; }
    public string ContentType { get; set; }
    public int Size { get; set; }
    public bool IsInline { get; set; }
    public DateTime LastModifiedDateTime { get; set; }
    public string ContentId { get; set; }
}

并对我的代码稍作改动，将其转换为流：

// get the file
BlobContainerClient containerClient = _blobServiceClient.GetBlobContainerClient(containerName);
BlobClient blobClient = containerClient.GetBlobClient(fileName);
BlobDownloadInfo download = await blobClient.DownloadAsync();
        
// convert the stream to an azure blob object
StreamReader reader = new StreamReader(download.Content);
string fileContents = reader.ReadToEnd();
AzureBlob blob = JsonSerializer.Deserialize<AzureBlob>(fileContents);

// convert the stock file to a stream
Stream stockFileStream = new MemoryStream(blob.ContentBytes);

Azure Logic App Store Excel 电子邮件附件到 Blob，下载并阅读

Azure Logic App Store Excel Email Attachment To Blob, Download and Read

c#

azure-blob-storage

openxml