我正在尝试调整旧逻辑以支持来自 blob 的文件,任何人都可以指导我如何打开存储在 azure blob 存储中的 pdf 文件。
我尝试搜索并找到了答案如何从Azure Blob存储将文件下载到浏览器 这是使用 SAS 配置来做到这一点(如果我没记错的话)。
有什么方法可以转换为字节吗?
从 Windows 位置打开 pdf 文件的早期逻辑
Response.Buffer = true;
Response.Clear();
Response.ClearContent();
Response.ClearHeaders();
Response.ContentType = "application/pdf";
Response.AppendHeader("content-disposition", "inline; filename=" + mapid + ".pdf");
FileStream fs = new FileStream(filename, FileMode.Open, FileAccess.Read, FileShare.Read);
BinaryReader br = new BinaryReader(fs);
Byte[] dataBytes = br.ReadBytes((int)(fs.Length - 1));
Response.BinaryWrite(dataBytes);
br.Close();
fs.Close();
我正在重写从 blob 读取文件的逻辑,下面的代码是我迄今为止尝试过的,
Byte[] dataBytes1;
CloudBlockBlob blobfile = GetStorageAccount(true).GetBlockBlobReference(filename);
blobfile.FetchAttributes();
using (StreamReader blobfilestream = new StreamReader(blobfile.OpenRead()))
{
dataBytes1 = blobfilestream.CurrentEncoding.GetBytes(blobfilestream.ReadToEnd());
}
Byte[] value = BitConverter.GetBytes(dataBytes1.Length - 1);
Response.BinaryWrite(value);
但是文件无法打开,并出现错误“加载失败”。 如果这是一个好的方法,谁能指导我?
您可以使用 DownloadToStreamAsync 并使用
Response.OutputStream
作为目标流。
await blob.DownloadToStreamAsync(Response.OutputStream);
您可以使用
DownloadToByteArray
,示例代码(在asp.net mvc项目中)如下,在我这边工作得很好:
public ActionResult DownloadFile()
{
CloudStorageAccount storageAccount = new CloudStorageAccount(new StorageCredentials("your_account", "your_key"), true);
CloudBlobClient client = storageAccount.CreateCloudBlobClient();
CloudBlobContainer blobContainer = client.GetContainerReference("t11");
CloudBlockBlob blob = blobContainer.GetBlockBlobReference("ss22.pdf");
blob.FetchAttributes();
long fileByteLength = blob.Properties.Length;
byte[] fileContent = new byte[fileByteLength];
for (int i=0;i<fileByteLength;i++)
{
fileContent[i] = 0x20;
}
blob.DownloadToByteArray(fileContent,0);
Response.BinaryWrite(fileContent);
return new EmptyResult();
}
或者按照 @hardkoded 提到的,您可以根据需要使用
DownloadToStreamAsync
或 DownloadToStream
。
示例代码如下(asp.net mvc项目):
public ActionResult DownloadFile()
{
CloudStorageAccount storageAccount = new CloudStorageAccount(new StorageCredentials("your_account", "your_key"),true);
CloudBlobClient client = storageAccount.CreateCloudBlobClient();
CloudBlobContainer blobContainer = client.GetContainerReference("t11");
CloudBlockBlob blob = blobContainer.GetBlockBlobReference("ss22.pdf");
blob.DownloadToStream(Response.OutputStream);
return new EmptyResult();
}
正如上面硬编码提到的,您需要使用 DownloadToStreamAsync。下面是我的代码。
blobfile.FetchAttributes();
using (StreamReader blobfilestream = new StreamReader(blobfile.OpenRead()))
{
dataBytes1 = blobfilestream.CurrentEncoding.GetBytes(blobfilestream.ReadToEnd());
await blobfile.DownloadToStreamAsync(Response.OutputStream);
}
Byte[] value = BitConverter.GetBytes(dataBytes1.Length - 1);
string mimeType = "application/pdf";
Response.AppendHeader("Content-Disposition", "inline; filename="+ filename);
return File(value, mimeType);
public async System.Threading.Tasks.Task<ActionResult> DownloadFile()
{
CloudStorageAccount storageAccount = CloudStorageAccount.Parse(
ConfigurationManager.ConnectionStrings["azureconnectionstring"].ConnectionString);
CloudBlobClient client = storageAccount.CreateCloudBlobClient();
CloudBlobContainer blobContainer = client.GetContainerReference("my-blob-storage");
CloudBlockBlob blob = blobContainer.GetBlockBlobReference("filename.pdf");
var exists = blob.Exists(); // to verify if file exist
blob.FetchAttributes();
byte[] dataBytes1;
using (StreamReader blobfilestream = new StreamReader(blob.OpenRead()))
{
dataBytes1 = blobfilestream.CurrentEncoding.GetBytes(blobfilestream.ReadToEnd());
await blob.DownloadToStreamAsync(Response.OutputStream);
}
Byte[] value = BitConverter.GetBytes(dataBytes1.Length - 1);
string mimeType = "application/pdf";
Response.AppendHeader("Content-Disposition", "inline; filename=" + "filename.pdf");
return File(value, mimeType);
}