Using ASP.NET MVC in React DocumentEditor component

[HttpPost]
[EnableCors("*", "*", "*")]
[Route("Import")]
public HttpResponseMessage Import()
{
        if (HttpContext.Current.Request.Files.Count == 0)
            return null;

        HttpPostedFile file = HttpContext.Current.Request.Files[0];
        int index = file.FileName.LastIndexOf('.');
        string type = index > -1 && index < file.FileName.Length - 1 ?
            file.FileName.Substring(index) : ".docx";
        Stream stream = file.InputStream;
        stream.Position = 0;
        //Convert the input word document into sfdt.
        EJ2WordDocument document = EJ2WordDocument.Load(stream, GetFormatType(type.ToLower()));
        string json = Newtonsoft.Json.JsonConvert.SerializeObject(document);
        document.Dispose();
        return new HttpResponseMessage() { Content = new StringContent(json) };
}

[HttpPost]
[EnableCors("*", "*", "*")]
[Route("SystemClipboard")]
public HttpResponseMessage SystemClipboard([FromBody]CustomParameter param)
{
    if (param.content != null && param.content != "")
    {
            try
            {
                //Convert the pasted content into sfdt.
                Syncfusion.EJ2.DocumentEditor.WordDocument document = Syncfusion.EJ2.DocumentEditor.WordDocument.LoadString(param.content, GetFormatType(param.type.ToLower()));
                string json = Newtonsoft.Json.JsonConvert.SerializeObject(document);
                document.Dispose();
                return new HttpResponseMessage() { Content = new StringContent(json) };
            }
            catch (Exception)
            {
                return new HttpResponseMessage() { Content = new StringContent("") };
            }

    }
    return new HttpResponseMessage() { Content = new StringContent("") };
}

public class CustomParameter
{
        public string content { get; set; }
        public string type { get; set; }
}

[HttpPost]
[EnableCors("*", "*", "*")]
[Route("RestrictEditing")]
public string[] RestrictEditing([FromBody]CustomRestrictParameter param)
{
        if (param.passwordBase64 == "" && param.passwordBase64 == null)
            return null;
        //Compure hash value for the specified password.
        return Syncfusion.EJ2.DocumentEditor.WordDocument.ComputeHash(param.passwordBase64, param.saltBase64, param.spinCount);
}

public class CustomRestrictParameter
{
        public string passwordBase64 { get; set; }
        public string saltBase64 { get; set; }
        public int spinCount { get; set; }
}

[HttpPost]
[EnableCors("*", "*", "*")]
[Route("SpellCheck")]
public HttpResponseMessage SpellCheck([FromBody] SpellCheckJsonData spellChecker)
{
        try
        {
            SpellChecker spellCheck = new SpellChecker(spellDictionary);
            //Check spelling and get suggestions.
            spellCheck.GetSuggestions(spellChecker.LanguageID, spellChecker.TexttoCheck, spellChecker.CheckSpelling, spellChecker.CheckSuggestion, spellChecker.AddWord);
            string json = Newtonsoft.Json.JsonConvert.SerializeObject(spellCheck);
            return new HttpResponseMessage() { Content = new StringContent(json) };
        }
        catch
        {
            return new HttpResponseMessage() { Content = new StringContent("{\"SpellCollection\":[],\"HasSpellingError\":false,\"Suggestions\":null}") };
        }
}

[HttpPost]
[EnableCors("*", "*", "*")]
[Route("SpellCheckByPage")]
public HttpResponseMessage SpellCheckByPage([FromBody] SpellCheckJsonData spellChecker)
{
        try
        {
            SpellChecker spellCheck = new SpellChecker(spellDictionary);
            //Check spelling for the specified text.
            spellCheck.CheckSpelling(spellChecker.LanguageID, spellChecker.TexttoCheck);
            string json = Newtonsoft.Json.JsonConvert.SerializeObject(spellCheck);
            return new HttpResponseMessage() { Content = new StringContent(json) };
        }
        catch
        {
            return new HttpResponseMessage() { Content = new StringContent("{\"SpellCollection\":[],\"HasSpellingError\":false,\"Suggestions\":null}") };
        }
}

public class SpellCheckJsonData
{
        public int LanguageID { get; set; }
        public string TexttoCheck { get; set; }
        public bool CheckSpelling { get; set; }
        public bool CheckSuggestion { get; set; }
        public bool AddWord { get; set; }
}