set Content-Type based on file extension

- Modified WriteAsync to detect MIME type from blob path using _mime.TryGetContentType
- Falls back to "application/octet-stream" when no mapping is found
- Uses BlobUploadOptions with BlobHttpHeaders to ensure Content-Type is stored
- Fixes issue where browsers download images instead of rendering inline

Author: aixasz

FluentStorage.Azure.Blobs/AzureBlobStorage.cs

@@ -14,20 +14,23 @@
 using Azure.Storage.Sas;
 using Blobs;
 using Microsoft.Identity.Client;
+using Microsoft.AspNetCore.StaticFiles;
 using FluentStorage.Blobs;
 using FluentStorage.Azure.Blobs.Gen2.Model;
 
 namespace FluentStorage.Azure.Blobs {
 	//auth scenarios: https://github.com/Azure/azure-sdk-for-net/blob/master/sdk/storage/Azure.Storage.Blobs/samples/Sample02_Auth.cs
 
 
-	class AzureBlobStorage : IAzureBlobStorage {
+		class AzureBlobStorage : IAzureBlobStorage {
 
 		private readonly BlobServiceClient _client;
 		private readonly StorageSharedKeyCredential _sasSigningCredentials;
 		private readonly string _containerName;
 		private readonly ConcurrentDictionary<string, BlobContainerClient> _containerNameToContainerClient =
 		   new ConcurrentDictionary<string, BlobContainerClient>();
+		private static readonly FileExtensionContentTypeProvider _mime =
+		   new FileExtensionContentTypeProvider();
 
 		public AzureBlobStorage(
 		   BlobServiceClient blobServiceClient,
@@ -129,9 +132,19 @@ public async Task WriteAsync(string fullPath, Stream dataStream,
 
 			BlockBlobClient client = container.GetBlockBlobClient(path);
 
+			string contentType;
+			if (!_mime.TryGetContentType(path, out contentType)) {
+				contentType = "application/octet-stream";
+			}
 			try {
+				var options = new BlobUploadOptions {
+					HttpHeaders = new BlobHttpHeaders {
+						ContentType = contentType
+					}
+				};
 				await client.UploadAsync(
 				   new StorageSourceStream(dataStream),
+				   options: options,
 				   cancellationToken: cancellationToken).ConfigureAwait(false);
 			}
 			catch (RequestFailedException ex) when (ex.ErrorCode == "OperationNotAllowedInCurrentState") {

FluentStorage.Azure.Blobs/FluentStorage.Azure.Blobs.csproj

@@ -29,6 +29,7 @@
    <ItemGroup>
       <PackageReference Include="Azure.Identity" Version="1.11.4" />
       <PackageReference Include="Azure.Storage.Blobs" Version="12.20.0" />
+      <PackageReference Include="Microsoft.AspNetCore.StaticFiles" Version="2.3.0" />
    </ItemGroup>
 
    <ItemGroup Condition=" '$(TargetFramework)' == 'netstandard2.0' or '$(TargetFramework)' == 'netstandard2.1' ">