From d14e6d7ce71dbef35f8d130327214e7a78bc57f2 Mon Sep 17 00:00:00 2001
From: Ruchira Gamage <rgamage@microsoft.com>
Date: Thu, 16 Apr 2026 11:21:31 +1200
Subject: [PATCH 1/7] Add Azure.Storage.Blobs 12.24.0 package for blob storage
 support

---
 ContosoUniversity/ContosoUniversity.csproj | 44 ++++++++++++++++------
 ContosoUniversity/packages.config          | 18 ++++++---
 2 files changed, 45 insertions(+), 17 deletions(-)

diff --git a/ContosoUniversity/ContosoUniversity.csproj b/ContosoUniversity/ContosoUniversity.csproj
index 8f49c50d..e8bf2eb7 100644
--- a/ContosoUniversity/ContosoUniversity.csproj
+++ b/ContosoUniversity/ContosoUniversity.csproj
@@ -45,11 +45,43 @@
     <WarningLevel>4</WarningLevel>
   </PropertyGroup>
   <ItemGroup>
+    <Reference Include="Azure.Storage.Blobs, Version=12.24.0.0, Culture=neutral, PublicKeyToken=92742159e12e44c8, processorArchitecture=MSIL">
+      <HintPath>packages\Azure.Storage.Blobs.12.24.0\lib\netstandard2.0\Azure.Storage.Blobs.dll</HintPath>
+      <Private>True</Private>
+    </Reference>
+    <Reference Include="Azure.Storage.Common, Version=12.23.0.0, Culture=neutral, PublicKeyToken=92742159e12e44c8, processorArchitecture=MSIL">
+      <HintPath>packages\Azure.Storage.Common.12.23.0\lib\netstandard2.0\Azure.Storage.Common.dll</HintPath>
+      <Private>True</Private>
+    </Reference>
     <Reference Include="Microsoft.CSharp" />
     <Reference Include="System" />
     <Reference Include="System.Data" />
     <Reference Include="System.Data.DataSetExtensions" />
+    <Reference Include="System.Diagnostics.DiagnosticSource, Version=6.0.0.1, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51, processorArchitecture=MSIL">
+      <HintPath>packages\System.Diagnostics.DiagnosticSource.6.0.1\lib\net461\System.Diagnostics.DiagnosticSource.dll</HintPath>
+      <Private>True</Private>
+    </Reference>
     <Reference Include="System.Drawing" />
+    <Reference Include="System.IO.Hashing, Version=6.0.0.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51, processorArchitecture=MSIL">
+      <HintPath>packages\System.IO.Hashing.6.0.0\lib\net461\System.IO.Hashing.dll</HintPath>
+      <Private>True</Private>
+    </Reference>
+    <Reference Include="System.Runtime.CompilerServices.Unsafe, Version=6.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a, processorArchitecture=MSIL">
+      <HintPath>packages\System.Runtime.CompilerServices.Unsafe.6.0.0\lib\net461\System.Runtime.CompilerServices.Unsafe.dll</HintPath>
+      <Private>True</Private>
+    </Reference>
+    <Reference Include="System.Text.Encodings.Web, Version=6.0.0.1, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51, processorArchitecture=MSIL">
+      <HintPath>packages\System.Text.Encodings.Web.6.0.1\lib\net461\System.Text.Encodings.Web.dll</HintPath>
+      <Private>True</Private>
+    </Reference>
+    <Reference Include="System.Text.Json, Version=6.0.0.11, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51, processorArchitecture=MSIL">
+      <HintPath>packages\System.Text.Json.6.0.11\lib\net461\System.Text.Json.dll</HintPath>
+      <Private>True</Private>
+    </Reference>
+    <Reference Include="System.ValueTuple, Version=4.0.3.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51, processorArchitecture=MSIL">
+      <HintPath>packages\System.ValueTuple.4.5.0\lib\net47\System.ValueTuple.dll</HintPath>
+      <Private>True</Private>
+    </Reference>
     <Reference Include="System.Web.DynamicData" />
     <Reference Include="System.Web.Entity" />
     <Reference Include="System.Web.ApplicationServices" />
@@ -135,10 +167,6 @@
       <HintPath>packages\Microsoft.Data.SqlClient.2.1.4\lib\net46\Microsoft.Data.SqlClient.dll</HintPath>
       <Private>True</Private>
     </Reference>
-    <Reference Include="Microsoft.Bcl.AsyncInterfaces">
-      <HintPath>packages\Microsoft.Bcl.AsyncInterfaces.1.1.1\lib\netstandard2.0\Microsoft.Bcl.AsyncInterfaces.dll</HintPath>
-      <Private>True</Private>
-    </Reference>
     <Reference Include="System.Threading.Tasks.Extensions">
       <HintPath>packages\System.Threading.Tasks.Extensions.4.5.4\lib\net461\System.Threading.Tasks.Extensions.dll</HintPath>
       <Private>True</Private>
@@ -187,10 +215,6 @@
       <HintPath>packages\Microsoft.Extensions.Primitives.3.1.32\lib\netstandard2.0\Microsoft.Extensions.Primitives.dll</HintPath>
       <Private>True</Private>
     </Reference>
-    <Reference Include="System.Diagnostics.DiagnosticSource">
-      <HintPath>packages\System.Diagnostics.DiagnosticSource.4.7.1\lib\net46\System.Diagnostics.DiagnosticSource.dll</HintPath>
-      <Private>True</Private>
-    </Reference>
     <Reference Include="System.Collections.Immutable">
       <HintPath>packages\System.Collections.Immutable.1.7.1\lib\netstandard2.0\System.Collections.Immutable.dll</HintPath>
       <Private>True</Private>
@@ -199,10 +223,6 @@
       <HintPath>packages\System.ComponentModel.Annotations.4.7.0\lib\net461\System.ComponentModel.Annotations.dll</HintPath>
       <Private>True</Private>
     </Reference>
-    <Reference Include="Microsoft.Identity.Client">
-      <HintPath>packages\Microsoft.Identity.Client.4.21.1\lib\net461\Microsoft.Identity.Client.dll</HintPath>
-      <Private>True</Private>
-    </Reference>
   </ItemGroup>
   <ItemGroup>
     <Reference Include="Microsoft.CodeDom.Providers.DotNetCompilerPlatform">
diff --git a/ContosoUniversity/packages.config b/ContosoUniversity/packages.config
index 3fc0a3d8..ac060c1c 100644
--- a/ContosoUniversity/packages.config
+++ b/ContosoUniversity/packages.config
@@ -1,6 +1,9 @@
 <?xml version="1.0" encoding="utf-8"?>
 <packages>
   <package id="Antlr" version="3.4.1.9004" targetFramework="net482" />
+  <package id="Azure.Core" version="1.44.1" targetFramework="net48" />
+  <package id="Azure.Storage.Blobs" version="12.24.0" targetFramework="net48" />
+  <package id="Azure.Storage.Common" version="12.23.0" targetFramework="net48" />
   <package id="bootstrap" version="5.3.3" targetFramework="net482" />
   <package id="jQuery" version="3.7.1" targetFramework="net482" />
   <package id="jQuery.Validation" version="1.21.0" targetFramework="net482" />
@@ -8,12 +11,11 @@
   <package id="Microsoft.AspNet.Razor" version="3.2.9" targetFramework="net482" />
   <package id="Microsoft.AspNet.Web.Optimization" version="1.1.3" targetFramework="net482" />
   <package id="Microsoft.AspNet.WebPages" version="3.2.9" targetFramework="net482" />
-  <package id="Microsoft.Bcl.AsyncInterfaces" version="1.1.1" targetFramework="net482" />
+  <package id="Microsoft.Bcl.AsyncInterfaces" version="6.0.0" targetFramework="net48" />
   <package id="Microsoft.Bcl.HashCode" version="1.1.1" targetFramework="net482" />
   <package id="Microsoft.CodeDom.Providers.DotNetCompilerPlatform" version="2.0.1" targetFramework="net482" />
   <package id="Microsoft.Data.SqlClient" version="2.1.4" targetFramework="net482" />
   <package id="Microsoft.Data.SqlClient.SNI.runtime" version="2.1.1" targetFramework="net482" />
-  <package id="Microsoft.Identity.Client" version="4.21.1" targetFramework="net482" />
   <package id="Microsoft.EntityFrameworkCore" version="3.1.32" targetFramework="net482" />
   <package id="Microsoft.EntityFrameworkCore.Abstractions" version="3.1.32" targetFramework="net482" />
   <package id="Microsoft.EntityFrameworkCore.Analyzers" version="3.1.32" targetFramework="net482" />
@@ -31,18 +33,24 @@
   <package id="Microsoft.Extensions.Logging.Abstractions" version="3.1.32" targetFramework="net482" />
   <package id="Microsoft.Extensions.Options" version="3.1.32" targetFramework="net482" />
   <package id="Microsoft.Extensions.Primitives" version="3.1.32" targetFramework="net482" />
+  <package id="Microsoft.Identity.Client" version="4.21.1" targetFramework="net482" />
   <package id="Microsoft.jQuery.Unobtrusive.Validation" version="4.0.0" targetFramework="net482" />
   <package id="Microsoft.Web.Infrastructure" version="2.0.1" targetFramework="net482" />
   <package id="Modernizr" version="2.6.2" targetFramework="net482" />
   <package id="NETStandard.Library" version="2.0.3" targetFramework="net482" />
   <package id="Newtonsoft.Json" version="13.0.3" targetFramework="net482" />
   <package id="System.Buffers" version="4.5.1" targetFramework="net482" />
+  <package id="System.ClientModel" version="1.1.0" targetFramework="net48" />
   <package id="System.Collections.Immutable" version="1.7.1" targetFramework="net482" />
   <package id="System.ComponentModel.Annotations" version="4.7.0" targetFramework="net482" />
-  <package id="System.Diagnostics.DiagnosticSource" version="4.7.1" targetFramework="net482" />
-  <package id="System.Memory" version="4.5.4" targetFramework="net482" />
+  <package id="System.Diagnostics.DiagnosticSource" version="6.0.1" targetFramework="net48" />
+  <package id="System.IO.Hashing" version="6.0.0" targetFramework="net48" />
+  <package id="System.Memory.Data" version="6.0.0" targetFramework="net48" />
   <package id="System.Numerics.Vectors" version="4.5.0" targetFramework="net482" />
-  <package id="System.Runtime.CompilerServices.Unsafe" version="4.5.3" targetFramework="net482" />
+  <package id="System.Runtime.CompilerServices.Unsafe" version="6.0.0" targetFramework="net48" />
+  <package id="System.Text.Encodings.Web" version="6.0.1" targetFramework="net48" />
+  <package id="System.Text.Json" version="6.0.11" targetFramework="net48" />
   <package id="System.Threading.Tasks.Extensions" version="4.5.4" targetFramework="net482" />
+  <package id="System.ValueTuple" version="4.5.0" targetFramework="net48" />
   <package id="WebGrease" version="1.5.2" targetFramework="net482" />
 </packages>
\ No newline at end of file

From 77c4721a68609be65c99356adb02760e3241c759 Mon Sep 17 00:00:00 2001
From: Ruchira Gamage <rgamage@microsoft.com>
Date: Thu, 16 Apr 2026 11:22:00 +1200
Subject: [PATCH 2/7] Add Azure Blob Storage configuration to Web.config

---
 ContosoUniversity/Web.config | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/ContosoUniversity/Web.config b/ContosoUniversity/Web.config
index f9257e0e..f59cd54c 100644
--- a/ContosoUniversity/Web.config
+++ b/ContosoUniversity/Web.config
@@ -17,6 +17,9 @@
     <add key="UnobtrusiveJavaScriptEnabled" value="true"/>
     <!-- Notification Queue Configuration -->
     <add key="NotificationQueuePath" value=".\Private$\ContosoUniversityNotifications"/>
+    <!-- Azure Blob Storage Configuration -->
+    <add key="AzureStorageBlob:Endpoint" value="https://yourstorageaccount.blob.core.windows.net"/>
+    <add key="AzureStorageBlob:ContainerName" value="teaching-materials"/>
   </appSettings>
   <!--
     For a description of web.config changes see http://go.microsoft.com/fwlink/?LinkId=235367.

From 19b95afd9b30bb3b65a66d9b2e1b2c297939e3c6 Mon Sep 17 00:00:00 2001
From: Ruchira Gamage <rgamage@microsoft.com>
Date: Thu, 16 Apr 2026 11:22:48 +1200
Subject: [PATCH 3/7] Create BlobStorageService for Azure Blob Storage
 operations

---
 .../Services/BlobStorageService.cs            | 172 ++++++++++++++++++
 1 file changed, 172 insertions(+)
 create mode 100644 ContosoUniversity/Services/BlobStorageService.cs

diff --git a/ContosoUniversity/Services/BlobStorageService.cs b/ContosoUniversity/Services/BlobStorageService.cs
new file mode 100644
index 00000000..487d2111
--- /dev/null
+++ b/ContosoUniversity/Services/BlobStorageService.cs
@@ -0,0 +1,172 @@
+using System;
+using System.Configuration;
+using System.IO;
+using System.Threading.Tasks;
+using Azure.Identity;
+using Azure.Storage.Blobs;
+using Azure.Storage.Blobs.Models;
+
+namespace ContosoUniversity.Services
+{
+    public class BlobStorageService : IDisposable
+    {
+        private readonly BlobServiceClient _blobServiceClient;
+        private readonly string _containerName;
+
+        public BlobStorageService()
+        {
+            // Get configuration from Web.config
+            string endpoint = ConfigurationManager.AppSettings["AzureStorageBlob:Endpoint"];
+            _containerName = ConfigurationManager.AppSettings["AzureStorageBlob:ContainerName"];
+
+            if (string.IsNullOrEmpty(endpoint))
+            {
+                throw new InvalidOperationException("AzureStorageBlob:Endpoint configuration is missing in Web.config");
+            }
+
+            if (string.IsNullOrEmpty(_containerName))
+            {
+                throw new InvalidOperationException("AzureStorageBlob:ContainerName configuration is missing in Web.config");
+            }
+
+            // Create BlobServiceClient using DefaultAzureCredential for Managed Identity support
+            _blobServiceClient = new BlobServiceClient(
+                new Uri(endpoint),
+                new DefaultAzureCredential());
+
+            // Ensure container exists
+            EnsureContainerExists();
+        }
+
+        private void EnsureContainerExists()
+        {
+            try
+            {
+                var containerClient = _blobServiceClient.GetBlobContainerClient(_containerName);
+                
+                // Create container if it doesn't exist with public read access for blobs
+                containerClient.CreateIfNotExists(PublicAccessType.Blob);
+            }
+            catch (Exception ex)
+            {
+                System.Diagnostics.Debug.WriteLine($"Error ensuring container exists: {ex.Message}");
+                // Don't throw - container might already exist or will be created on first upload
+            }
+        }
+
+        /// <summary>
+        /// Uploads a file to Azure Blob Storage
+        /// </summary>
+        /// <param name="stream">File stream to upload</param>
+        /// <param name="blobName">Name for the blob (e.g., "course_1045_guid.jpg")</param>
+        /// <param name="contentType">Content type of the file (e.g., "image/jpeg")</param>
+        /// <returns>URI of the uploaded blob</returns>
+        public async Task<string> UploadBlobAsync(Stream stream, string blobName, string contentType)
+        {
+            try
+            {
+                var containerClient = _blobServiceClient.GetBlobContainerClient(_containerName);
+                var blobClient = containerClient.GetBlobClient(blobName);
+
+                // Set blob upload options with content type
+                var uploadOptions = new BlobUploadOptions
+                {
+                    HttpHeaders = new BlobHttpHeaders
+                    {
+                        ContentType = contentType
+                    }
+                };
+
+                // Upload the blob
+                await blobClient.UploadAsync(stream, uploadOptions);
+
+                // Return the blob URI
+                return blobClient.Uri.ToString();
+            }
+            catch (Exception ex)
+            {
+                System.Diagnostics.Debug.WriteLine($"Error uploading blob {blobName}: {ex.Message}");
+                throw new ApplicationException($"Failed to upload file to blob storage: {ex.Message}", ex);
+            }
+        }
+
+        /// <summary>
+        /// Deletes a blob from Azure Blob Storage
+        /// </summary>
+        /// <param name="blobUri">Full URI of the blob to delete</param>
+        /// <returns>True if deleted, false if not found</returns>
+        public async Task<bool> DeleteBlobAsync(string blobUri)
+        {
+            if (string.IsNullOrEmpty(blobUri))
+            {
+                return false;
+            }
+
+            try
+            {
+                // Extract blob name from URI
+                var uri = new Uri(blobUri);
+                var blobName = uri.Segments[uri.Segments.Length - 1];
+
+                var containerClient = _blobServiceClient.GetBlobContainerClient(_containerName);
+                var blobClient = containerClient.GetBlobClient(blobName);
+
+                // Delete the blob if it exists
+                var response = await blobClient.DeleteIfExistsAsync();
+                return response.Value;
+            }
+            catch (Exception ex)
+            {
+                System.Diagnostics.Debug.WriteLine($"Error deleting blob {blobUri}: {ex.Message}");
+                // Return false instead of throwing to avoid breaking course deletion
+                return false;
+            }
+        }
+
+        /// <summary>
+        /// Gets the URI for a blob
+        /// </summary>
+        /// <param name="blobName">Name of the blob</param>
+        /// <returns>URI of the blob</returns>
+        public string GetBlobUri(string blobName)
+        {
+            var containerClient = _blobServiceClient.GetBlobContainerClient(_containerName);
+            var blobClient = containerClient.GetBlobClient(blobName);
+            return blobClient.Uri.ToString();
+        }
+
+        /// <summary>
+        /// Checks if a blob exists
+        /// </summary>
+        /// <param name="blobUri">Full URI of the blob</param>
+        /// <returns>True if exists, false otherwise</returns>
+        public async Task<bool> BlobExistsAsync(string blobUri)
+        {
+            if (string.IsNullOrEmpty(blobUri))
+            {
+                return false;
+            }
+
+            try
+            {
+                var uri = new Uri(blobUri);
+                var blobName = uri.Segments[uri.Segments.Length - 1];
+
+                var containerClient = _blobServiceClient.GetBlobContainerClient(_containerName);
+                var blobClient = containerClient.GetBlobClient(blobName);
+
+                var response = await blobClient.ExistsAsync();
+                return response.Value;
+            }
+            catch
+            {
+                return false;
+            }
+        }
+
+        public void Dispose()
+        {
+            // BlobServiceClient doesn't require explicit disposal
+        }
+    }
+}

From a1e484506dd672b4d0303f77f662854939175274 Mon Sep 17 00:00:00 2001
From: Ruchira Gamage <rgamage@microsoft.com>
Date: Thu, 16 Apr 2026 11:23:16 +1200
Subject: [PATCH 4/7] Add BlobStorageService to BaseController

---
 ContosoUniversity/Controllers/BaseController.cs | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/ContosoUniversity/Controllers/BaseController.cs b/ContosoUniversity/Controllers/BaseController.cs
index 5e46cefb..ca4f4707 100644
--- a/ContosoUniversity/Controllers/BaseController.cs
+++ b/ContosoUniversity/Controllers/BaseController.cs
@@ -10,6 +10,7 @@ public abstract class BaseController : Controller
     {
         protected SchoolContext db;
         protected NotificationService notificationService = new NotificationService();
+        protected BlobStorageService blobStorageService = new BlobStorageService();
 
         public BaseController()
         {
@@ -41,6 +42,7 @@ protected override void Dispose(bool disposing)
             {
                 db?.Dispose();
                 notificationService?.Dispose();
+                blobStorageService?.Dispose();
             }
             base.Dispose(disposing);
         }

From 8a288663d88bae8e5528ad2eaaf4e2712d603dac Mon Sep 17 00:00:00 2001
From: Ruchira Gamage <rgamage@microsoft.com>
Date: Thu, 16 Apr 2026 13:08:23 +1200
Subject: [PATCH 5/7] Integrate Azure Blob Storage for course material images

Replaced local file storage with Azure Blob Storage for uploading and managing course teaching material images in CoursesController. Added BlobStorageService to handle blob operations. Old blobs are deleted on update, and image paths now store blob URIs instead of local paths. Removed all local file system image handling logic.
---
 ContosoUniversity/ContosoUniversity.csproj    |  1 +
 .../Controllers/CoursesController.cs          | 62 ++++++++-----------
 2 files changed, 26 insertions(+), 37 deletions(-)

diff --git a/ContosoUniversity/ContosoUniversity.csproj b/ContosoUniversity/ContosoUniversity.csproj
index e8bf2eb7..b61d6481 100644
--- a/ContosoUniversity/ContosoUniversity.csproj
+++ b/ContosoUniversity/ContosoUniversity.csproj
@@ -262,6 +262,7 @@
     <Compile Include="Models\SchoolViewModels\InstructorIndexData.cs" />
     <Compile Include="PaginatedList.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
+    <Compile Include="Services\BlobStorageService.cs" />
     <Compile Include="Services\NotificationService.cs" />
   </ItemGroup>
   <ItemGroup>
diff --git a/ContosoUniversity/Controllers/CoursesController.cs b/ContosoUniversity/Controllers/CoursesController.cs
index 32706841..0e1e4ca8 100644
--- a/ContosoUniversity/Controllers/CoursesController.cs
+++ b/ContosoUniversity/Controllers/CoursesController.cs
@@ -54,7 +54,7 @@ public ActionResult Create([Bind(Include = "CourseID,Title,Credits,DepartmentID,
                     // Validate file type
                     var allowedExtensions = new[] { ".jpg", ".jpeg", ".png", ".gif", ".bmp" };
                     var fileExtension = Path.GetExtension(teachingMaterialImage.FileName).ToLower();
-                    
+
                     if (!allowedExtensions.Contains(fileExtension))
                     {
                         ModelState.AddModelError("teachingMaterialImage", "Please upload a valid image file (jpg, jpeg, png, gif, bmp).");
@@ -72,20 +72,16 @@ public ActionResult Create([Bind(Include = "CourseID,Title,Credits,DepartmentID,
 
                     try
                     {
-                        // Create uploads directory if it doesn't exist
-                        var uploadsPath = Server.MapPath("~/Uploads/TeachingMaterials/");
-                        if (!Directory.Exists(uploadsPath))
-                        {
-                            Directory.CreateDirectory(uploadsPath);
-                        }
+                        // Generate unique blob name
+                        var blobName = $"course_{course.CourseID}_{Guid.NewGuid()}{fileExtension}";
 
-                        // Generate unique filename
-                        var fileName = $"course_{course.CourseID}_{Guid.NewGuid()}{fileExtension}";
-                        var filePath = Path.Combine(uploadsPath, fileName);
+                        // Upload to Azure Blob Storage
+                        var blobUri = blobStorageService.UploadBlobAsync(
+                            teachingMaterialImage.InputStream,
+                            blobName,
+                            teachingMaterialImage.ContentType).Result;
 
-                        // Save file
-                        teachingMaterialImage.SaveAs(filePath);
-                        course.TeachingMaterialImagePath = $"~/Uploads/TeachingMaterials/{fileName}";
+                        course.TeachingMaterialImagePath = blobUri;
                     }
                     catch (Exception ex)
                     {
@@ -97,10 +93,10 @@ public ActionResult Create([Bind(Include = "CourseID,Title,Credits,DepartmentID,
 
                 db.Courses.Add(course);
                 db.SaveChanges();
-                
+
                 // Send notification for course creation
                 SendEntityNotification("Course", course.CourseID.ToString(), course.Title, EntityOperation.CREATE);
-                
+
                 return RedirectToAction("Index");
             }
 
@@ -137,7 +133,7 @@ public ActionResult Edit([Bind(Include = "CourseID,Title,Credits,DepartmentID,Te
                     // Validate file type
                     var allowedExtensions = new[] { ".jpg", ".jpeg", ".png", ".gif", ".bmp" };
                     var fileExtension = Path.GetExtension(teachingMaterialImage.FileName).ToLower();
-                    
+
                     if (!allowedExtensions.Contains(fileExtension))
                     {
                         ModelState.AddModelError("teachingMaterialImage", "Please upload a valid image file (jpg, jpeg, png, gif, bmp).");
@@ -155,30 +151,22 @@ public ActionResult Edit([Bind(Include = "CourseID,Title,Credits,DepartmentID,Te
 
                     try
                     {
-                        // Create uploads directory if it doesn't exist
-                        var uploadsPath = Server.MapPath("~/Uploads/TeachingMaterials/");
-                        if (!Directory.Exists(uploadsPath))
+                        // Delete old blob if exists
+                        if (!string.IsNullOrEmpty(course.TeachingMaterialImagePath))
                         {
-                            Directory.CreateDirectory(uploadsPath);
+                            blobStorageService.DeleteBlobAsync(course.TeachingMaterialImagePath).Wait();
                         }
 
-                        // Generate unique filename
-                        var fileName = $"course_{course.CourseID}_{Guid.NewGuid()}{fileExtension}";
-                        var filePath = Path.Combine(uploadsPath, fileName);
+                        // Generate unique blob name
+                        var blobName = $"course_{course.CourseID}_{Guid.NewGuid()}{fileExtension}";
 
-                        // Delete old file if exists
-                        if (!string.IsNullOrEmpty(course.TeachingMaterialImagePath))
-                        {
-                            var oldFilePath = Server.MapPath(course.TeachingMaterialImagePath);
-                            if (System.IO.File.Exists(oldFilePath))
-                            {
-                                System.IO.File.Delete(oldFilePath);
-                            }
-                        }
+                        // Upload new blob to Azure Blob Storage
+                        var blobUri = blobStorageService.UploadBlobAsync(
+                            teachingMaterialImage.InputStream,
+                            blobName,
+                            teachingMaterialImage.ContentType).Result;
 
-                        // Save new file
-                        teachingMaterialImage.SaveAs(filePath);
-                        course.TeachingMaterialImagePath = $"~/Uploads/TeachingMaterials/{fileName}";
+                        course.TeachingMaterialImagePath = blobUri;
                     }
                     catch (Exception ex)
                     {
@@ -190,10 +178,10 @@ public ActionResult Edit([Bind(Include = "CourseID,Title,Credits,DepartmentID,Te
 
                 db.Entry(course).State = EntityState.Modified;
                 db.SaveChanges();
-                
+
                 // Send notification for course update
                 SendEntityNotification("Course", course.CourseID.ToString(), course.Title, EntityOperation.UPDATE);
-                
+
                 return RedirectToAction("Index");
             }
             ViewBag.DepartmentID = new SelectList(db.Departments, "DepartmentID", "Name", course.DepartmentID);

From 379663dbc6245ff188bec3db0c6153b0ff1e9413 Mon Sep 17 00:00:00 2001
From: Ruchira Gamage <rgamage@microsoft.com>
Date: Thu, 16 Apr 2026 13:30:33 +1200
Subject: [PATCH 6/7] Migrate CoursesController DeleteConfirmed action from
 local file system to Azure Blob Storage

---
 .../Controllers/CoursesController.cs          | 21 +++++++------------
 1 file changed, 8 insertions(+), 13 deletions(-)

diff --git a/ContosoUniversity/Controllers/CoursesController.cs b/ContosoUniversity/Controllers/CoursesController.cs
index 0e1e4ca8..43e87e77 100644
--- a/ContosoUniversity/Controllers/CoursesController.cs
+++ b/ContosoUniversity/Controllers/CoursesController.cs
@@ -211,22 +211,17 @@ public ActionResult DeleteConfirmed(int id)
             Course course = db.Courses.Find(id);
             var courseTitle = course.Title;
             
-            // Delete associated image file if it exists
+            // Delete associated image from Azure Blob Storage if it exists
             if (!string.IsNullOrEmpty(course.TeachingMaterialImagePath))
             {
-                var filePath = Server.MapPath(course.TeachingMaterialImagePath);
-                if (System.IO.File.Exists(filePath))
+                try
                 {
-                    try
-                    {
-                        System.IO.File.Delete(filePath);
-                    }
-                    catch (Exception ex)
-                    {
-                        // Log the error but don't prevent deletion of the course
-                        // In a production application, you would log this error properly
-                        System.Diagnostics.Debug.WriteLine($"Error deleting file: {ex.Message}");
-                    }
+                    blobStorageService.DeleteBlobAsync(course.TeachingMaterialImagePath).Wait();
+                }
+                catch (Exception ex)
+                {
+                    // Log the error but don't prevent deletion of the course
+                    System.Diagnostics.Debug.WriteLine($"Error deleting blob: {ex.Message}");
                 }
             }
             

From 8759fcd8e39929e2a2dd9f64eb412e876c54105a Mon Sep 17 00:00:00 2001
From: Ruchira Gamage <rgamage@microsoft.com>
Date: Thu, 16 Apr 2026 13:34:44 +1200
Subject: [PATCH 7/7] Fix BlobStorageService to use connection string auth, add
 missing assembly references, update Web.config

---
 ContosoUniversity/ContosoUniversity.csproj       | 16 ++++++++++++++++
 ContosoUniversity/Services/BlobStorageService.cs | 13 +++++--------
 ContosoUniversity/Web.config                     |  2 +-
 ContosoUniversity/packages.config                |  1 -
 4 files changed, 22 insertions(+), 10 deletions(-)

diff --git a/ContosoUniversity/ContosoUniversity.csproj b/ContosoUniversity/ContosoUniversity.csproj
index b61d6481..66ae2904 100644
--- a/ContosoUniversity/ContosoUniversity.csproj
+++ b/ContosoUniversity/ContosoUniversity.csproj
@@ -49,6 +49,22 @@
       <HintPath>packages\Azure.Storage.Blobs.12.24.0\lib\netstandard2.0\Azure.Storage.Blobs.dll</HintPath>
       <Private>True</Private>
     </Reference>
+    <Reference Include="Azure.Core, Version=1.44.1.0, Culture=neutral, PublicKeyToken=92742159e12e44c8, processorArchitecture=MSIL">
+      <HintPath>packages\Azure.Core.1.44.1\lib\netstandard2.0\Azure.Core.dll</HintPath>
+      <Private>True</Private>
+    </Reference>
+    <Reference Include="Microsoft.Bcl.AsyncInterfaces, Version=6.0.0.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51, processorArchitecture=MSIL">
+      <HintPath>packages\Microsoft.Bcl.AsyncInterfaces.6.0.0\lib\net461\Microsoft.Bcl.AsyncInterfaces.dll</HintPath>
+      <Private>True</Private>
+    </Reference>
+    <Reference Include="System.ClientModel, Version=1.1.0.0, Culture=neutral, PublicKeyToken=92742159e12e44c8, processorArchitecture=MSIL">
+      <HintPath>packages\System.ClientModel.1.1.0\lib\netstandard2.0\System.ClientModel.dll</HintPath>
+      <Private>True</Private>
+    </Reference>
+    <Reference Include="System.Memory.Data, Version=6.0.0.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51, processorArchitecture=MSIL">
+      <HintPath>packages\System.Memory.Data.6.0.0\lib\netstandard2.0\System.Memory.Data.dll</HintPath>
+      <Private>True</Private>
+    </Reference>
     <Reference Include="Azure.Storage.Common, Version=12.23.0.0, Culture=neutral, PublicKeyToken=92742159e12e44c8, processorArchitecture=MSIL">
       <HintPath>packages\Azure.Storage.Common.12.23.0\lib\netstandard2.0\Azure.Storage.Common.dll</HintPath>
       <Private>True</Private>
diff --git a/ContosoUniversity/Services/BlobStorageService.cs b/ContosoUniversity/Services/BlobStorageService.cs
index 487d2111..b88867f0 100644
--- a/ContosoUniversity/Services/BlobStorageService.cs
+++ b/ContosoUniversity/Services/BlobStorageService.cs
@@ -2,7 +2,6 @@
 using System.Configuration;
 using System.IO;
 using System.Threading.Tasks;
-using Azure.Identity;
 using Azure.Storage.Blobs;
 using Azure.Storage.Blobs.Models;
 
@@ -16,12 +15,12 @@ public class BlobStorageService : IDisposable
         public BlobStorageService()
         {
             // Get configuration from Web.config
-            string endpoint = ConfigurationManager.AppSettings["AzureStorageBlob:Endpoint"];
+            string connectionString = ConfigurationManager.AppSettings["AzureStorageBlob:ConnectionString"];
             _containerName = ConfigurationManager.AppSettings["AzureStorageBlob:ContainerName"];
 
-            if (string.IsNullOrEmpty(endpoint))
+            if (string.IsNullOrEmpty(connectionString))
             {
-                throw new InvalidOperationException("AzureStorageBlob:Endpoint configuration is missing in Web.config");
+                throw new InvalidOperationException("AzureStorageBlob:ConnectionString configuration is missing in Web.config");
             }
 
             if (string.IsNullOrEmpty(_containerName))
@@ -29,10 +28,8 @@ public BlobStorageService()
                 throw new InvalidOperationException("AzureStorageBlob:ContainerName configuration is missing in Web.config");
             }
 
-            // Create BlobServiceClient using DefaultAzureCredential for Managed Identity support
-            _blobServiceClient = new BlobServiceClient(
-                new Uri(endpoint),
-                new DefaultAzureCredential());
+            // Create BlobServiceClient using connection string
+            _blobServiceClient = new BlobServiceClient(connectionString);
 
             // Ensure container exists
             EnsureContainerExists();
diff --git a/ContosoUniversity/Web.config b/ContosoUniversity/Web.config
index f59cd54c..b1522a23 100644
--- a/ContosoUniversity/Web.config
+++ b/ContosoUniversity/Web.config
@@ -18,7 +18,7 @@
     <!-- Notification Queue Configuration -->
     <add key="NotificationQueuePath" value=".\Private$\ContosoUniversityNotifications"/>
     <!-- Azure Blob Storage Configuration -->
-    <add key="AzureStorageBlob:Endpoint" value="https://yourstorageaccount.blob.core.windows.net"/>
+    <add key="AzureStorageBlob:ConnectionString" value="DefaultEndpointsProtocol=https;AccountName=yourstorageaccount;AccountKey=your-account-key;EndpointSuffix=core.windows.net"/>
     <add key="AzureStorageBlob:ContainerName" value="teaching-materials"/>
   </appSettings>
   <!--
diff --git a/ContosoUniversity/packages.config b/ContosoUniversity/packages.config
index ac060c1c..7efa39a2 100644
--- a/ContosoUniversity/packages.config
+++ b/ContosoUniversity/packages.config
@@ -33,7 +33,6 @@
   <package id="Microsoft.Extensions.Logging.Abstractions" version="3.1.32" targetFramework="net482" />
   <package id="Microsoft.Extensions.Options" version="3.1.32" targetFramework="net482" />
   <package id="Microsoft.Extensions.Primitives" version="3.1.32" targetFramework="net482" />
-  <package id="Microsoft.Identity.Client" version="4.21.1" targetFramework="net482" />
   <package id="Microsoft.jQuery.Unobtrusive.Validation" version="4.0.0" targetFramework="net482" />
   <package id="Microsoft.Web.Infrastructure" version="2.0.1" targetFramework="net482" />
   <package id="Modernizr" version="2.6.2" targetFramework="net482" />