Post data with a request in a Windows Store app WebView - using C#

I have the following scenario in my app:

At first startup, the user can register an account. The app then gets a pair (int user_id, string session_id) from my webserver and stores that data in-app.

In my app I use a WebView which lets the user look at some content of my site. Using the user_id and the session_id, he gets logged in automatically (after that, server side session and cookies are created).

I did not want to use an url scheme like http://mobile.mysite.com/?user_id=int&session_id=string, so I decided to use http post to send the user_id and session_id.

In iOS it was very easy:

// Post the user data and load the website in the webview
NSString *startUrl = @"http://mobile.mysite.com/";
NSString *post = [NSString stringWithFormat:@"user_id=%@&session_id=%@, [user uid], [user sessionId]];
NSMutableURLRequest *request = [[NSMutableURLRequest alloc] initWithURL:[NSURL URLWithString:startUrl]];
[request setHTTPMethod:@"POST"];
[request setHTTPBody:[post dataUsingEncoding: NSUTF8StringEncoding]];
[webView loadRequest:request];

So here I am, having done the same structure in my Windows 8 Store app in C#. Unfortunately, WebView does not let me post the user info to the server.

Do you have an idea how I could solve my problem?

One idea would be to make a http request and share the cookie with the WebView. But that does not look very elegant to me...

Solution

POST with WebView in Windows 8.1

Or even better, use WebView.NavigateWithHttpRequestMessage(HttpRequestMessage requestMessage).

You can use a Windows.Web.Http.HttpRequestMessage to set the HTTP method and the request content among other things.

E.g.:

HttpRequestMessage request = new HttpRequestMessage(
    HttpMethod.Post,
    new Uri("http://localhost"));
request.Content = new HttpStringContent(
    String.Format("user_id={0}&session_id={1}", "Chinese", "food"));
webView.NavigateWithHttpRequestMessage(request);

That would be equivalent to the following HTTP request:

POST / HTTP/1.1
Accept: text/html, application/xhtml+xml, */*
Accept-Language: en-US,en;q=0.5
User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; Trident/7.0; Touch; MASAJS; WebView/2.0; rv:11.0) like Gecko
Accept-Encoding: gzip, deflate
Host: localhost
Content-Length: 31
Connection: Keep-Alive
Cache-Control: no-cache

user_id=Chinese&session_id=food

POST with WebView in Windows 8

For Windows 8, do it with JavaScript!

Create a <form>, set the action to your destination URI and set the method to POST.
Add two <input> and name them with the names you want, in this case user_id and session_id.
Add a script that sets the inputs value and submit the form.

E.g.:

protected override void OnNavigatedTo(NavigationEventArgs e)
{
    webView.NavigateToString(@"<html>
    <head>
        <script type='text/javascript'>
            function doSomething(userIdValue, sessionIdValue) 
            { 
                document.getElementById('user_id').value = userIdValue;
                document.getElementById('session_id').value = sessionIdValue;
                document.getElementById('myForm').submit();
                return 'Hello World!'; 
            }
        </script>
    </head>
    <body>
        <form id='myForm' action='http://localhost' method='post'>
            <input type='hidden' id='user_id' name='user_id' />
            <input type='hidden' id='session_id' name='session_id' />
        </form>
    </body>
</html>");
}

private void Button_Click(object sender, RoutedEventArgs e)
{
    string result = webView.InvokeScript("doSomething", new string[] { "Chinese", "food" });
}

That would send a request like this:

POST / HTTP/1.1
Accept: text/html, application/xhtml+xml, */*
Accept-Language: en-US,en;q=0.5
User-Agent: Mozilla/5.0 (compatible; MSIE 10.0; Windows NT 6.2; WOW64; Trident/6.0; Touch; MASAJS; WebView/1.0)
Content-Type: application/x-www-form-urlencoded
Accept-Encoding: gzip, deflate
Host: localhost
Content-Length: 31
Connection: Keep-Alive
Cache-Control: no-cache

user_id=Chinese&session_id=food