Upload image to server

I need upload image to server using api. Now I'm using System.Net.Http;

        byte[] lFileBytes= DependencyService.Get<IFileHelper>().ReadAllBytes(ImagePath);
        ByteArrayContent lFileContent = new ByteArrayContent(lFileBytes,0,lFileBytes.Length);
        lFileContent.Headers.ContentDisposition = ContentDispositionHeaderValue.Parse("form-data");
        lFileContent.Headers.ContentType=new MediaTypeHeaderValue("image/jpg");
        lFileContent.Headers.ContentDisposition.Parameters.Add(new NameValueHeaderValue("name", "file"));
        lFileContent.Headers.ContentDisposition.Parameters.Add(new NameValueHeaderValue("filename", "9.jpg"));
        lFileContent.Headers.ContentLength= lFileBytes.Length;
        lContent.Add(lFileContent);

    public byte[] ReadAllBytes(string path) {
                using (var streamReader = new StreamReader(path))
                {
                    using (var memoryStream = new MemoryStream())
                    {
                        streamReader.BaseStream.CopyTo(memoryStream);
                        return memoryStream.ToArray();
                    }
                }
            }

After sending request i have error "Type file is invalid". I'm thinking problem in "byte[] ReadAllBytes(string path)" For request i can use Stream or byte[] Please, help