How interception request to get JS upload binary file content

[wenbei421]

I'm using cefsharp to host a web page that uses js to request a custom protocol Url and request interception in C#, but I can't get the binary content of the file。
js code:
function upload() {
// Form Data
var postData = new FormData();

        var fileSelect = document.getElementById("fileSelect");
        if (fileSelect.files && fileSelect.files.length == 1) {
            var file = fileSelect.files[0]
            postData.set("file", file, file.name);
        }

        axios.post('http://icreate.com/admincontroller/upload', postData)
            .then(response => {
                console.log(response.data)
            })
            .catch(error => {
                console.log(error)
            });
    }

C# code
public class DefaultRequestSchemeHandler : ResourceHandler
{
...
public override CefReturnValue ProcessRequestAsync(IRequest request, ICallback callback)
{
...
var postDataElements = request?.PostData?.Elements;
...
}
}
post data：

[amaitland]

There's already a discussion at #4134