Process image into custom size in .net core

In many places we are using custom size images like for creating thumbnails, media applications etc..

In .net core it’s very easy to process the image into new custom sized image.

Steps:

Install Nuget package System.Drawing.Common Version 4.5.1 into your project

Include a file control in the page with form enctype="multipart/form-data"

Exmple:

<form asp-action="ImageResizing" enctype="multipart/form-data">

        <div class="form-group">

            <div class="col-md-10">

                <p>Upload one file using this form:</p>

                <input type="file" name="formFile" />

            </div>

        </div>

        <div class="form-group">

            <div class="col-md-10">

                <input type="submit" value="Upload" />

            </div>

        </div>

    </form>

Whenever we submit this form it will hit the action ImageResizing.

.net core introduced a new interface IFormFile for sending file with the HttpRequest.

We can get the actual file in our controller like below

public async Task<IActionResult> ImageResizing(IFormFile formFile)

        {

//do your logic here

 }

Then pass the file stream into our ImageResizeMethod.

public async Task<IActionResult> ImageResizing(IFormFile formFile)

        {

            if (formFile.Length > 0)

            {

                var filePath = Path.GetTempFileName();

                using (var stream = new FileStream(filePath, FileMode.Create))

                {

                    await formFile.CopyToAsync(stream);

                   

                   Image newFile= GetReducedImage (32,32 stream);

                }

            }

            return View(nameof(Index));

        }

private Image GetReducedImage(int Width, int Height, Stream ResourceImage)

        {

            try

            {

                Image image = Image.FromStream(ResourceImage);

                Image thumb = image.GetThumbnailImage(Width, Height, () => false, IntPtr.Zero);

                return thumb;

            }

            catch (Exception e)

            {

                return null;

            }

        }