Get div class height

This is a solution using the headless browser Watin to get the height of a DOM element using inline javascript.

First install Watin using Visual Studio Nuget Package Manager Console by executing:

PM> Install-Package WatiN

After the successfull installation of Watin headless browser, you can use it like this to navigate to a page and run a simple javascript to retrieve an element's height:

using WatiN.Core;
...

private void buttonGetElementHeight_Click(object sender, EventArgs e)
{
    WatiN.Core.Settings.Instance.MakeNewIeInstanceVisible = false;
    IE browser = new IE();

    browser.GoToNoWait("https://m.investing.com/economic-calendar/");
    browser.WaitUntilContainsText("Filters");

    var height = browser.Eval("document.getElementsByClassName('js-economic-calendar')[0].offsetHeight");
    labelResult.Text = String.Format("Element height is {0}px", height);

    browser.ForceClose();
}

Here is a screen capture of the working button fetching the height:

EDIT

Beware that this is a test and you have to implement some error handling for both C# Watin objects and inline javascript that is being evaluated.

UPDATE

Here is how to do it using Windows.UI.Xaml.Controls.WebView:

private async void webView1_LoadCompleted(object sender, NavigationEventArgs e)
{
    var offsetHeight = await webView1.InvokeScriptAsync("eval", new string[] {
        "document.getElementsByClassName('js-economic-calendar')[0].offsetHeight.toString()"
    });
    textBox.Text = offsetHeight;
}

private async void button_Click(object sender, RoutedEventArgs e)
{
    webView1.LoadCompleted += webView1_LoadCompleted;
    webView1.Navigate(new Uri("https://m.investing.com/economic-calendar/"));
}

My working screen capture: