Question

我正在尝试设计一个简单的视图，用于将文件上传到azure存储容器中。上传后，我想捕获上传文件的BlockBlobReference，将引用存储在数据库字段中，以便能够下载该文件供以后使用。我已经意识到用于上传的视图和控制器（上传工作），但我不知道如何解决其余问题。

这是我的剃刀观点的一部分：

    <div>
    @using (Html.BeginForm("UploadTestFile", "Upload", FormMethod.Post, new { enctype = "multipart/form-data" }))
    {
    <span>Select File:</span>
    <input type="file" name="loadedFiles" multiple />
    <hr />
    <input type="submit" value="Upload" />
    <br />
    <span style="color:green">@ViewBag.Message</span>
    }
</div>

这是控制器和方法：

 [HttpPost]
    public void UploadTestFile(HttpPostedFileBase loadedFiles)
    {
        string containerName = "testcontainer";
        UploadFileToBlobStorage(containerName, loadedFiles);
    }

    public void UploadFileToBlobStorage(string containerName, HttpPostedFileBase loadedFiles)
    {
        // Retrieve storage account from connection string.
        CloudStorageAccount storageAccount = CloudStorageAccount.Parse(
            CloudConfigurationManager.GetSetting("StorageConnectionString"));

        // Create the blob client.
        CloudBlobClient blobClient = storageAccount.CreateCloudBlobClient();

        // Retrieve reference to a previously created container.
        CloudBlobContainer container = blobClient.GetContainerReference(containerName);

        // Create the container if it doesn't already exist.
        container.CreateIfNotExists();

        container.SetPermissions(
            new BlobContainerPermissions
            {
                PublicAccess =
                    BlobContainerPublicAccessType.Blob
            });

// here I would like to iterate through the items, in case that more than one file was selected
// I don't know how to iterate through loadedFiles though


     // filename
        string _fileName = loadedFiles.FileName;


        // Retrieve reference to a blob 
        CloudBlockBlob blockBlob =  container.GetBlockBlobReference(_fileName);

            blockBlob.UploadFromStream(loadedFiles.InputStream);
    }

请有人帮助我或给我一些提示。此致，Manu

Answer 1

您可以安全地存储文件名（以及容器名称，以防它可以更改）或url（取决于容器是否公开）。

如果容器是公开的，您只需使用blob网址：https://{yourstorageaccount}.blob.core.windows.net/{container}/{filename.extension}。

如果私有，您可以存储文件名并按如下方式读取文件：

public byte[] ReadFile(string containerName, string fileName)
{
    CloudStorageAccount storageAccount = CloudStorageAccount.Parse(CloudConfigurationManager.GetSetting("StorageConnectionString"));
    CloudBlobClient blobClient = storageAccount.CreateCloudBlobClient();
    var container = blobClient.GetContainerReference(containerName);
    var fileBase = container.GetBlockBlobReference(fileName);
    if (!fileBase.Exists())
    {
        return null;
    }
    fileBase.FetchAttributes();
    var fileByteLength = fileBase.Properties.Length;
    var fileByteArray = new Byte[fileByteLength];

    fileBase.DownloadToByteArray(fileByteArray, 0);
    return fileByteArray;
}

或者像这样，如果你想把内容作为一个字符串：

public string ReadFileAsString(string containerName, string fileName)
{
    CloudStorageAccount storageAccount = CloudStorageAccount.Parse(CloudConfigurationManager.GetSetting("StorageConnectionString"));
    CloudBlobClient blobClient = storageAccount.CreateCloudBlobClient();
    var container = blobClient.GetContainerReference(containerName);
    var fileBase = container.GetBlockBlobReference(fileName);
    if (!fileBase.Exists())
    {
        return null;
    }
    return fileBase.DownloadText(Encoding.UTF8, AccessCondition.GenerateEmptyCondition(), null, null);
}

如果要从MVC Action触发下载，可以执行以下操作：

public ActionResult GetFile(string fileName)
{
    CloudStorageAccount storageAccount = CloudStorageAccount.Parse(CloudConfigurationManager.GetSetting("StorageConnectionString"));
    CloudBlobClient blobClient = storageAccount.CreateCloudBlobClient();
    var container = blobClient.GetContainerReference("myContainer");
    var fileBase = container.GetBlockBlobReference(fileName);
    if (!fileBase.Exists())
    {
        return null;
    }
    fileBase.FetchAttributes();
    var fileByteLength = fileBase.Properties.Length;
    var fileByteArray = new Byte[fileByteLength];

    fileBase.DownloadToByteArray(fileByteArray, 0);

    return File(fileByteArray, fileBase.Properties.ContentType, fileName);
}

如何在上传时捕获azure blob引用

1 个答案: