.NET Core web API + Dapper – Image Upload

Steam of Bytes or Base64 Encoded

To test my Dapper based functionality to upload images to my World Wide Importers database I used Telerik Fiddler.

Fiddler Composer with the image field name and upload file button highlighted

The currentimplementation only supports the uploading of one image at a time in a field called “image”.

Fiddler console after succesfull upload

This implementation supports a “Content-Type” of “application/octet-stream” or “image/jpeg”.

public async Task<ActionResult> Upload([FromRoute(Name = "id")][Range(1, int.MaxValue, ErrorMessage = "StockItem id must greater than 0")] int id, [FromForm] IFormFile image)
	if (image == null) 
		return this.BadRequest("Image image file missing");

	if (image.Length == 0)
		return this.BadRequest("Image image file is empty");

	if ((string.Compare(image.ContentType, "application/octet-stream",true) != 0) && (string.Compare(image.ContentType, "image/jpeg", true) != 0))
		return this.BadRequest("Image image file content-type is not application/octet-stream or image/jpeg");

		using (MemoryStream ms = new MemoryStream())
			await image.CopyToAsync(ms);

			ms.Seek(0, SeekOrigin.Begin);

			using (SqlConnection db = new SqlConnection(this.connectionString))
				DynamicParameters parameters = new DynamicParameters();

				parameters.Add("StockItemId", id);
				parameters.Add("photo", ms, DbType.Binary, ParameterDirection.Input);

				await db.ExecuteAsync(sql: @"UPDATE [WareHouse].[StockItems] SET [Photo]=@Photo WHERE StockItemID=@StockItemId", param: parameters, commandType: CommandType.Text);
	catch (SqlException ex)
		logger.LogError(ex, "Updating photo of StockItem with ID:{0}", id);

		return this.StatusCode(StatusCodes.Status500InternalServerError);

	return this.Ok();

After uploading the image I could download it as either a stream of bytes(displayed in Fiddler) or Base64 encoded (this had to be converted to an image)

Fiddler displaying downloaded jpeg image

This implementation doesn’t support the uploading of multiple images or the streaming of larger images but would be sufficient for uploading thumbnails etc.

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