Resolving 'Malformed FormData Request' errors in C#

Resolving 'Malformed FormData Request' errors in C#

Created by Kesh Bhamidipaty, Modified on Thu, 13 Jun at 11:50 PM by Kesh Bhamidipaty

This article outlines likely causes for 'Malformed FormData Request' errors when using the Stability API in C#, and gives example approaches for resolving them.

Symptoms

The following shows the relevant bit of the HTTP response seen when making a request to a Stability API endpoint in C#:

{"success":false,"message":"Malformed FormData request. Content-Disposition header in FormData part is missing a name."}

Possible Root Cause & Solution

C# may not quote the Content-Disposition header by default. In this case, the following helper functions can be used as a workaround:

private static StringContent stringFormField(string name, string value) { var formField = new StringContent(value); formField.Headers.ContentDisposition = new ContentDispositionHeaderValue("form-data") { Name = $"\"{name}\"" }; return formField; } private static async Task<ByteArrayContent> imageFormField(string name, string imagePath, string mimeType) { var filename = Path.GetFileName(imagePath); var imageBytes = await File.ReadAllBytesAsync(imagePath); var formField = new ByteArrayContent(imageBytes); formField.Headers.ContentType = new MediaTypeHeaderValue(mimeType); formField.Headers.ContentDisposition = new ContentDispositionHeaderValue("form-data") { Name = $"\"{name}\"", FileName = $"\"{filename}\"" }; return formField; }

Which can be used like so: