Unrecognized element (File download)

Google does not allow such downloads by Google Drive .

  

To download files through Google Drive via code,   you make a HTTP GET request for the resource URL   of the file and includes the query parameter alt = media . Per   example:

GET https://www.googleapis.com/drive/v3/files/0B9jNhSvVjoIVM3dKcGRKRmVIOVU?alt=media

     

Authorization: Bearer

     

Downloading the file requires the user to have at least   reading. In addition, your application must be authorized with a scope   that allows reading the contents of the file. For example, a   application that uses the drive.readonly.metadata scope would not be   authorized to download the contents of the file. Users with permission   can restrict downloading by read-only users   setting the viewersCanCopyContent field to true .

     

Files identified as abusive (malware, etc.) can only be   downloaded by the owner. In addition, the query parameter    acknowledledgeAbuse = true should be included to indicate that the   threat of downloading potential malware. Your   application must notify the user interactively before using this   query parameter.

I would recommend that you put your file in another site, such as Dropbox , Azure Blob or files.fm , where do not need an exotic code to allow you to download files like Google Drive.

However, if you wanted to continue with Drive , the link below gives you how to do what you want.

Information taken from: Google Drive APIs

EDIT

I ended up passing the wrong information and in the case of Dropbox, you also need to use a DropboxClient to download files + a Token generated by the Dropbox API. That said, let's get down to business.

1. Create a Dropbox account

Go to Dropbox and create your account.

2. Create an App to Access a Token

Enter the Dropbox Developers site and create an App that will be used to generate a Token so that we can download of Dropbox files.

Onthescreenthatopens,selectDropboxAPI,thenselectFullDropbox,setanameforyourApp,andthenclickCreateApp.

3.GenerateaToken

Ontheopenscreen,lookforGeneratedaccesstokenandclickGenerate.Oncethisisdone,aTokenwillbegenerated.SavethisTokeninasafeplace.ItwillbeusedtoidentifyyourDropboxaccountviacode.

4.CreateafolderinDropbox

CreateafolderinDropboxandplacethefileyouwanttodownloadinthere.Youcanusethesamefoldertoplaceanytypeoffileyouwanttodownload.

Oncethisisdone,addthedesiredfile(s)intothecreatedfolder.Inthiscase,Iputafile.7z(zip)withthenameofcv_2018.

5.Createthedownloadcodeforthefile

privatestring_token="token_gerado_nas_etapas_anteriores";

public Form1()
{
    InitializeComponent();

    btnDownload.Click += Download_Click;
}

/// <summary>
/// Click do botão para download do arquivo
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private async void Download_Click(object sender, EventArgs e)
{
    try
    {
        DropboxClient client;

        client = new DropboxClient(_token);
        string folder = "DownloadFiles";
        string file = "cv_2018.7z";
        string destinationFolder = @"C:\Test";

        await Download(client, folder, file, destinationFolder);
    }
    catch (Exception ex)
    {
        Console.WriteLine($"Erro ao fazer download do arquivo: {ex.Message}");
    }
}

/// <summary>
/// Faz o download de um arquivo do Dropbox e salva localmente
/// </summary>
/// <param name="dbx">DropboxClient</param>
/// <param name="folder">Pasta onde se encontra o arquivo no Dropbox</param>
/// <param name="file">Nome do arquivo com a extensão no Dropbox</param>
/// <param name="destinationFolder">Pasta de destino no computador</param>
/// <returns></returns>
private async Task Download(DropboxClient dbx, string folder, string file, string destinationFolder)
{
    using (var response = await dbx.Files.DownloadAsync("/" + folder + "/" + file))
    {
        using (var fileStream = File.Create($"{destinationFolder}\{file}"))
        {
            (await response.GetContentAsStreamAsync()).CopyTo(fileStream);
        }
    }
}