C# WebBrowser Control - Form Submit Not Working using InvokeMember("Click")
I am working on automated testing script and am using the WebBrowser control. I am trying to submit the following HTML and testing when the user accepts the terms of service:
<form action="http://post.dev.dealerconnextion/k/6hRbDTwn4xGVl2MHITQsBw/hrshq" method="post">
<input name="StepCheck" value="U2FsdGVkX18zMTk5MzE5OUgFyFgD3V5yf5Rwbtfhf3gjdH4KSx4hqj4vkrw7K6e-" type="hidden">
<button type="submit" name="continue" value="y">ACCEPT the terms of use</button>
<button type="submit" name="continue" value="n">DECLINE the terms of use</button>
</form>
// Terms of Use Information
<form action="http://post.dev.dealerconnextion/k/6hRbDTwn4xGVl2MHITQsBw/hrshq" method="post">
<input name="StepCheck" value="U2FsdGVkX18zMTk5MzE5OUgFyFgD3V5yf5Rwbtfhf3gjdH4KSx4hqj4vkrw7K6e-" type="hidden">
<button type="submit" name="continue" value="y">ACCEPT the terms of use</button>
<button type="submit" name="continue" value="n">DECLINE the terms of use</button>
</form>
Here is the code in C#, but does not submit the form.
HtmlElementCollection el = webBrowser.Document.GetElementsByTagName("button");
foreach (HtmlElement btn in el)
{
if (btn.InnerText == "ACCEPT the terms of use")
{
btn.InvokeMember("Click");
}
}
Any help would be much appreciated. Thanks.
The following code works for me, using the live form action URL from the question comments, tested with IE10. Try it as is. If it works for you as well, feel free to use it as a template for your web automation tasks. A couple of points:
FEATURE_BROWSER_EMULATION is used to make sure the
WebBrowserbehaves in the same way as standalone IE browser (or as close as possible). This is a must for almost anyWebBrowser-based project. I believe that's what should help to solve the original problem on your side.Asynchronous code is used to improve the automation logic reliability, add support timeouts and cancellation and promote natural linear code flow (using
async/await).
C#:
using Microsoft.Win32;
using System;
using System.Diagnostics;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
using System.Windows.Forms;
namespace WebAutomation
{
// http://stackoverflow.com/q/19044659/1768303
public partial class MainForm : Form
{
WebBrowser webBrowser;
// non-deterministic delay to let AJAX code run
const int AJAX_DELAY = 1000;
// keep track of the main automation task
CancellationTokenSource mainCts;
Task mainTask = null;
public MainForm()
{
SetBrowserFeatureControl(); // set FEATURE_BROWSER_EMULATION first
InitializeComponent();
InitBrowser();
this.Load += (s, e) =>
{
// start the automation when form is loaded
// timeout the whole automation task in 30s
mainCts = new CancellationTokenSource(30000);
mainTask = DoAutomationAsync(mainCts.Token).ContinueWith((completedTask) =>
{
Trace.WriteLine(String.Format("Automation task status: {0}", completedTask.Status.ToString()));
}, TaskScheduler.FromCurrentSynchronizationContext());
};
this.FormClosing += (s, e) =>
{
// cancel the automation if form closes
if (this.mainTask != null && !this.mainTask.IsCompleted)
mainCts.Cancel();
};
}
// create a WebBrowser instance (could use an existing one)
void InitBrowser()
{
this.webBrowser = new WebBrowser();
this.webBrowser.Dock = DockStyle.Fill;
this.Controls.Add(this.webBrowser);
this.webBrowser.Visible = true;
}
// the main automation logic
async Task DoAutomationAsync(CancellationToken ct)
{
await NavigateAsync(ct, () => this.webBrowser.Navigate("http://localhost:81/test.html"), 10000); // timeout in 10s
// page loaded, log the page's HTML
Trace.WriteLine(GetBrowserDocumentHtml());
// do the DOM automation
HtmlElementCollection all = webBrowser.Document.GetElementsByTagName("button");
// throw if none or more than one element found
HtmlElement btn = all.Cast<HtmlElement>().Single(
el => el.InnerHtml == "ACCEPT the terms of use");
ct.ThrowIfCancellationRequested();
// simulate a click which causes navigation
await NavigateAsync(ct, () => btn.InvokeMember("click"), 10000); // timeout in 10s
// form submitted and new page loaded, log the page's HTML
Trace.WriteLine(GetBrowserDocumentHtml());
// could continue with another NavigateAsync
// othrwise, the automation session completed
}
// Get the full HTML content of the document
string GetBrowserDocumentHtml()
{
return this.webBrowser.Document.GetElementsByTagName("html")[0].OuterHtml;
}
// Async navigation
async Task NavigateAsync(CancellationToken ct, Action startNavigation, int timeout = Timeout.Infinite)
{
var onloadTcs = new TaskCompletionSource<bool>();
EventHandler onloadEventHandler = null;
WebBrowserDocumentCompletedEventHandler documentCompletedHandler = delegate
{
// DocumentCompleted may be called several time for the same page,
// beacuse of frames
if (onloadEventHandler != null || onloadTcs == null || onloadTcs.Task.IsCompleted)
return;
// handle DOM onload event to make sure the document is fully loaded
onloadEventHandler = (s, e) =>
onloadTcs.TrySetResult(true);
this.webBrowser.Document.Window.AttachEventHandler("onload", onloadEventHandler);
};
using (var cts = CancellationTokenSource.CreateLinkedTokenSource(ct))
{
if (timeout != Timeout.Infinite)
cts.CancelAfter(Timeout.Infinite);
using (cts.Token.Register(() => onloadTcs.TrySetCanceled(), useSynchronizationContext: true))
{
this.webBrowser.DocumentCompleted += documentCompletedHandler;
try
{
startNavigation();
// wait for DOM onload, throw if cancelled
await onloadTcs.Task;
ct.ThrowIfCancellationRequested();
// let AJAX code run, throw if cancelled
await Task.Delay(AJAX_DELAY, ct);
}
finally
{
this.webBrowser.DocumentCompleted -= documentCompletedHandler;
if (onloadEventHandler != null)
this.webBrowser.Document.Window.DetachEventHandler("onload", onloadEventHandler);
}
}
}
}
// Browser feature conntrol
void SetBrowserFeatureControl()
{
// http://msdn.microsoft.com/en-us/library/ee330720(v=vs.85).aspx
// FeatureControl settings are per-process
var fileName = System.IO.Path.GetFileName(Process.GetCurrentProcess().MainModule.FileName);
// make the control is not running inside Visual Studio Designer
if (String.Compare(fileName, "devenv.exe", true) == 0 || String.Compare(fileName, "XDesProc.exe", true) == 0)
return;
SetBrowserFeatureControlKey("FEATURE_BROWSER_EMULATION", fileName, GetBrowserEmulationMode()); // Webpages containing standards-based !DOCTYPE directives are displayed in IE10 Standards mode.
}
void SetBrowserFeatureControlKey(string feature, string appName, uint value)
{
using (var key = Registry.CurrentUser.CreateSubKey(
String.Concat(@"Software\Microsoft\Internet Explorer\Main\FeatureControl\", feature),
RegistryKeyPermissionCheck.ReadWriteSubTree))
{
key.SetValue(appName, (UInt32)value, RegistryValueKind.DWord);
}
}
UInt32 GetBrowserEmulationMode()
{
int browserVersion = 7;
using (var ieKey = Registry.LocalMachine.OpenSubKey(@"SOFTWARE\Microsoft\Internet Explorer",
RegistryKeyPermissionCheck.ReadSubTree,
System.Security.AccessControl.RegistryRights.QueryValues))
{
var version = ieKey.GetValue("svcVersion");
if (null == version)
{
version = ieKey.GetValue("Version");
if (null == version)
throw new ApplicationException("Microsoft Internet Explorer is required!");
}
int.TryParse(version.ToString().Split('.')[0], out browserVersion);
}
UInt32 mode = 10000; // Internet Explorer 10. Webpages containing standards-based !DOCTYPE directives are displayed in IE10 Standards mode. Default value for Internet Explorer 10.
switch (browserVersion)
{
case 7:
mode = 7000; // Webpages containing standards-based !DOCTYPE directives are displayed in IE7 Standards mode. Default value for applications hosting the WebBrowser Control.
break;
case 8:
mode = 8000; // Webpages containing standards-based !DOCTYPE directives are displayed in IE8 mode. Default value for Internet Explorer 8
break;
case 9:
mode = 9000; // Internet Explorer 9. Webpages containing standards-based !DOCTYPE directives are displayed in IE9 mode. Default value for Internet Explorer 9.
break;
default:
// use IE10 mode by default
break;
}
return mode;
}
}
}
The content of http://localhost:81/test.html:
<!DOCTYPE html>
<head>
<meta http-equiv="X-UA-Compatible" content="IE=edge"/>
</head>
<body>
<form action="<the URL from OP's comments>" method="post">
<input name="StepCheck" value="U2FsdGVkX18zMTk5MzE5OUgFyFgD3V5yf5Rwbtfhf3gjdH4KSx4hqj4vkrw7K6e-" type="hidden">
<button type="submit" name="continue" value="y">ACCEPT the terms of use</button>
<button type="submit" name="continue" value="n">DECLINE the terms of use</button>
</form>
</body>
This works for me as follow. may that would be useful for someone.
First I create an event handler for the button element when got focus. Once all the other form element are filled up with the appropriate values, You should give the focus to the button as follow:
HtmlElement xUsername = xDoc.GetElementById("username_txt");
HtmlElement xPassword = xDoc.GetElementById("password_txt");
HtmlElement btnSubmit = xDoc.GetElementById("btnSubmit");
if (xUsername != null && xPassword != null && btnSubmit != null)
{
xUsername.SetAttribute("value", "testUserName");
xPassword.SetAttribute("value", "123456789");
btnSubmit.GotFocus += BtnSubmit_GotFocus;
btnSubmit.Focus();
}
Then event handler implementation would be like this:
private void BtnSubmit_GotFocus(object sender, HtmlElementEventArgs e)
{
var btnSubmit = sender as HtmlElement;
btnSubmit.RaiseEvent("onclick");
btnSubmit.InvokeMember("click");
}