如何在MonoDroid中使用WCF上传大文件

Question

I'm trying to implement WCF into MonoDroid. I think there's no big difference between it and MonoTouch on this issue. And after researching, I counldn't find the supoort for anyother WCF binding mode except BasicHttpBinding.

Honestly I'm not good that WCF at all, so I just tried ways randomly. I can get messages from server with string and byte[] and so on, but when i wanted to upload large data eg. image or audio, the uploaded message which includes big byte[] must be limited under 8192bytes. That causes my uploading into failure.

Now what I can do is to convert the big byte[] into Base64String and split it into 8000bytes pieces, and execute a bunch of commands like UploadAsyn(orderNumber, uploadStringBlock), and reform them up again in server with the orderNumber. and convert back to bytes from Base64string. Very busy and silly!

Otherwise I must think other way to solve large file uploading from mobile phone.

And it's really a big pity and problem not to make all actions achieved totally inside WCF coding.

Hope Mono improve it. and if any help welcome and appreciated.

Answer 1

Your best bet is to not use WCF to upload the data, but instead use a plain HTTP transfer. Use WCF to securely obtain an upload token which could be just a url that encodes both the address where you can perform an HTTP POST and the parameters to associate the POST with the user/state that you are uploading.

For example, your WCF request could do this:

string GetTokenForUpload ()
{
    var uuid = new UUID ();
    db.Insert (key: uuid, for: "upload", login: user.Credentials);
    return base_url + "?id=" + uuid; 
}

Then on your POST handler for a regular ASHX handler, you can do something like:

PostRequest (HttpRequest req, QueryString qstring)
{
    id = qstring ["id"];
    if (!db.Lookup (id, out userCredentials))
        error ();
    // accept post for the user.
}