How to Combine iFormFile with a String Parameter in ASP.NET Core AJAX Requests

Discover how to send an image file along with a string parameter in your ASP.NET Core application. This guide provides a clear solution and code examples!
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How to Combine iFormFile with a String Parameter in ASP.NET Core AJAX Requests

Are you trying to upload an image file and simultaneously send a string parameter using AJAX in an ASP.NET Core application? If you find that the string parameter is showing a null value, you're not alone. This issue is common when handling file uploads alongside other data. In this guide, we'll explore how to effectively send both an iFormFile and a string parameter to your server-side controller.

The Problem

When you want to upload files (like images) through AJAX, you often face the challenge of combining that file with additional information, such as a folder name. Your AJAX request might look fine initially, but due to certain settings in your request, you may notice the server is receiving null for your string parameter.

Example Scenario

Consider a situation where you want to upload an image and specify the folder name where the image should be stored. You might have set up the following JavaScript to capture the image and folder name for your request:

[[See Video to Reveal this Text or Code Snippet]]

In the above code, the folder name is captured, but it isn't sent with the rest of the data. This is the root of the problem.

The Solution

To successfully send both the image file and the folder name in one request, you need to append the folder name to your FormData. Here's how you can modify your existing code:

Updated JavaScript Code

[[See Video to Reveal this Text or Code Snippet]]

Breakdown of Changes

No Changes to AJAX Settings: Keep processData: false and contentType: false to properly handle file uploads.

Controller Setup

Ensure your controller is properly set up to handle both the IFormFile and the string parameter:

[[See Video to Reveal this Text or Code Snippet]]

Key Points in the Controller

Folder Creation: Your controller checks for specific folder names and adjusts them accordingly for storage.

File Handling: The file is created and streamed to the target directory once the request is handled.

Conclusion

Sending an image file along with a string parameter in ASP.NET Core via AJAX is straightforward once you know how to combine them in a FormData object. By following the steps outlined above, you can ensure that both pieces of data are sent correctly to your backend, allowing for a seamless file upload experience.

Feel free to reach out if you have any more questions or need further assistance on this topic!