Add support for sending files by Telegram file ID

FileResult now supports file IDs in addition to streams, with a new constructor and logic in ExecuteResultAsync. Added FileId method to BotControllerBase for convenience. Updated Telegram.Bot package to 22.9.6.

Author: Vadim Belov

Sources/TelegramBot/ActionResults/FileResult.cs

@@ -15,6 +15,7 @@ public class FileResult : IActionResult, IDisposable
         private bool _disposed;
         private readonly string _fileName;
         private readonly Stream _fileStream;
+        private readonly InputFileId? _inputFile;
         private readonly bool _disposeStream = true;
 
         /// <summary>
@@ -40,6 +41,19 @@ public FileResult(Stream stream, string fileName, bool disposeStream = true)
             _disposeStream = disposeStream;
         }
 
+        /// <summary>
+        /// Initializes a new instance of the FileResult class using the specified input file identifier.
+        /// </summary>
+        /// <remarks>The file name is initialized to an empty string, and the file stream is set to a null
+        /// stream.</remarks>
+        /// <param name="inputFileId">The identifier of the input file to be processed. This parameter cannot be null.</param>
+        public FileResult(InputFileId inputFileId)
+        {
+            _inputFile = inputFileId;
+            _fileName = string.Empty;
+            _fileStream = Stream.Null;
+        }
+
         /// <summary>
         /// Disposes the file stream if it is applicable.
         /// </summary>
@@ -59,7 +73,15 @@ public void Dispose()
         /// <returns>The task representing the result of the action.</returns>
         public Task ExecuteResultAsync(ActionContext context)
         {
-            InputFile file = InputFile.FromStream(_fileStream, _fileName);
+            InputFile file;
+            if (_inputFile != null)
+            {
+                file = _inputFile;
+            }
+            else
+            {
+                file = InputFile.FromStream(_fileStream, _fileName);
+            }
             return context.Bot.SendDocument(context.ChatId, document: file);
         }
     }

Sources/TelegramBot/Controllers/BotControllerBase.cs

@@ -175,6 +175,15 @@ public IActionResult File(Stream stream, string fileName, bool disposeStream = t
             return new FileResult(stream, fileName, disposeStream);
         }
 
+        public IActionResult FileId(string fileId)
+        {
+            if (string.IsNullOrWhiteSpace(fileId))
+            {
+                throw new ArgumentNullException(nameof(fileId));
+            }
+            return new FileResult(InputFile.FromFileId(fileId));
+        }
+
         /// <summary>
         /// Sends an image to the sender.
         /// </summary>

Sources/TelegramBot/TelegramBot.csproj

@@ -28,7 +28,7 @@
 		<None Include="..\..\README.md" Pack="true" PackagePath="\" />
 		<None Include="icon.png" Pack="true" PackagePath="\" />
 		<None Include="..\..\LICENSE.md" Pack="true" PackagePath="LICENSE.md" />
-		<PackageReference Include="Telegram.Bot" Version="22.9.5.3" />
+		<PackageReference Include="Telegram.Bot" Version="22.9.6" />
 		<PackageReference Include="System.Text.Json" Version="10.0.5" />
 		<PackageReference Include="Microsoft.Extensions.Logging" Version="10.0.5" />
 		<PackageReference Include="Microsoft.Extensions.Configuration" Version="10.0.5" />