Added extension methods for FormFile

src/Microsoft.AspNet.Http.Extensions/FormFileExtensions.cs

@@ -0,0 +1,47 @@
+// Copyright (c) Microsoft Open Technologies, Inc. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using System.IO;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace Microsoft.AspNet.Http
+{
+    /// <summary>
+    /// Extension methods for <see cref="IFormFile"/>.
+    /// </summary>
+    public static class FormFileExtensions
+    {
+        private static int DefaultBufferSize = 81920;
+
+        /// <summary>
+        /// Saves the contents of an uploaded file.
+        /// </summary>
+        /// <param name="formFile">The <see cref="IFormFile"/>.</param>
+        /// <param name="filename">The name of the file to create.</param>
+        public static void SaveAs([NotNull] this IFormFile formFile, string filename)
+        {
+            using (var fileStream = new FileStream(filename, FileMode.Create))
+            {
+                var inputStream = formFile.OpenReadStream();
+                inputStream.CopyTo(fileStream);
+            }
+        }
+
+        /// <summary>
+        /// Asynchronously saves the contents of an uploaded file.
+        /// </summary>
+        /// <param name="formFile">The <see cref="IFormFile"/>.</param>
+        /// <param name="filename">The name of the file to create.</param>
+        public async static Task SaveAsAsync([NotNull] this IFormFile formFile,
+                                             string filename,
+                                             CancellationToken cancellationToken = default(CancellationToken))
+        {
+            using (var fileStream = new FileStream(filename, FileMode.Create))
+            {
+                var inputStream = formFile.OpenReadStream();
+                await inputStream.CopyToAsync(fileStream, DefaultBufferSize, cancellationToken);
+            }
+        }
+    }
+}