Adding URL-encoded form content

Add URL-encoded form content to the multipart form content.

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HttpRequestBuilder.Post("https://furion.net")    .SetMultipartContent(multipart =>    {        multipart.AddFormUrlEncoded(new { id = 1 ,name = "Furion" }, "form");        multipart.AddFormUrlEncoded(new { id = 1 ,name = "Furion" }, "form", useStringContent: true);   // Use StringContent to solve the encoding problem of FormUrlEncodedContent        // Supports the URL-encoded string format        multipart.AddFormUrlEncoded("id=1&name=Furion", "form", useStringContent: true);    });

Notes on URL-encoded form content

By default, URL-encoded forms are built using the FormUrlEncodedContent type, but this type does not support custom request content encoding; it uses Encoding.Latin1 by default instead of UTF-8. This may cause exceptions when submitting to certain endpoints.

To solve this problem, you can set the useStringContent parameter to true to build the form data using StringContent, thereby allowing custom encoding to UTF-8.
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var content = await httpRemoteService.PostAsAsync<YourRemoteModel>("https://localhost:7044/HttpRemote/AddURLForm", builder => builder .SetFormUrlEncodedContent(new { id = 1, name = "furion" }, useStringContent: true));
Some servers require an explicit charset declaration, in which case you can specify the encoding via the contentEncoding parameter, for example using UTF-8:
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var content = await httpRemoteService.PostAsAsync<YourRemoteModel>("https://localhost:7044/HttpRemote/AddURLForm", builder => builder .SetFormUrlEncodedContent(new { id = 1, name = "furion" }, Encoding.UTF8));
When sending the remote request, this setting generates the following Content-Type request header: application/x-www-form-urlencoded; charset=UTF-8.