Download File from Blob-Storage .net core Azure Function C#

Alexander-Cojti — Sat, 23 Nov 2019 21:28:56 +0000

Couple days ago I tried to use Azure Function to build an API manipulating "blob storage operations CRUD", I having investigated a solution to solve the download operation, since the majority internet solutions I found work it locally but while deploy my function the Web server needs the grant permission path to Create File and download locally which generated the error:"Access to path is denied". Then I Solved download via HTTP response whit Azure function V2, C# .net core 2.1 This is the basic code it works me, I hope it helps you...

using System.Threading.Tasks;
using Microsoft.Azure.WebJobs;
using Microsoft.Azure.WebJobs.Extensions.Http;
using Microsoft.AspNetCore.Http;
using Microsoft.WindowsAzure.Storage;
using Microsoft.WindowsAzure.Storage.Blob;
using Microsoft.WindowsAzure.Storage.Auth;
using System.IO;
using System.Net.Http.Headers;
using System.Net.Http;
using System.Net;

namespace BloApi
{
public static class BlobOperations
{
[FunctionName("DownloadBlob")]
public static async Task DownloadBlob(
[HttpTrigger(AuthorizationLevel.Anonymous, "get", Route = "DownloadBlob/{name}")] HttpRequest req, string name)
{
StorageCredentials storageCredentials = new StorageCredentials("Storage",
"CamEKgqVaylmQ.....ow2VHlyCww==");
CloudStorageAccount storageAccount = new CloudStorageAccount(storageCredentials, true);
CloudBlobContainer container = storageAccount.CreateCloudBlobClient().GetContainerReference("BlobContainer");
var blobName = name;
CloudBlockBlob block = container.GetBlockBlobReference(blobName);
HttpResponseMessage message = new HttpResponseMessage(HttpStatusCode.OK);
Stream blobStream = await block.OpenReadAsync();
message.Content = new StreamContent(blobStream);
message.Content.Headers.ContentLength = block.Properties.Length;
message.StatusCode = HttpStatusCode.OK;
message.Content.Headers.ContentType = new MediaTypeHeaderValue(block.Properties.ContentType);
message.Content.Headers.ContentDisposition = new ContentDispositionHeaderValue("attachment")
{
FileName = $"CopyOf_{block.Name}",
Size = block.Properties.Length
};
return message;
}
}
}

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Download File from Blob-Storage .net core Azure Function C#