Closing ChromiumWebBrowser instance causes app to freeze

[Tyler Jones]

I have a winforms form that instantiates a ChromiumWebBrowser instance in it's constructor, when the form is initialized.  I have a FormClosing() function that runs whenever the form closes both from clicking the "x" button, and when calling .Close().  When I close the form using the "x" button, i'm able to dispose the Browser object without an issue, in the FormClosing method.  However, if I call .Close() on the form, when I .Dispose() line is hit in FormClosing() on that same Browser object, my app freezes for about 30 seconds, leading me to believe the Browser object is on a different thread.  

However, if I check .InvokeRequired on the Browser object, it returns false.  How can I dispose of the ChromiumWebBrowser instance without causing the app to freeze?  Why does .Dispose() work fine when clicking the "x" button?

Here is my constructor:

public PhxCEFBrowser(string url)

{

InitializeComponent();

Browser = new ChromiumWebBrowser(url)

{

Dock = DockStyle.Fill,

Location = new Point(0, 0),

MinimumSize = new Size(20, 20),

Name = "webBrowser1",

Size = new Size(284, 261),

TabIndex = 0,

};

Browser.BrowserSettings.ApplicationCacheDisabled = true;

Browser.KeyboardHandler = new KeyboardHandler();

browserPanel.Controls.Add(Browser);

        ClientSize = new Size(284, 261);

        Name = "WebBrowser";

        ResumeLayout(false);

}

And here is my FormClosing() handler:

private void PhxCEFBrowser_FormClosing(object sender, FormClosingEventArgs e)

{

browserPanel.Controls.Remove(Browser);

if (Browser.InvokeRequired)//<-- Returns false

{

Browser.Invoke(new MethodInvoker(delegate

{

Browser.Dispose();//<-- never gets hit

}));

}

else

{

Browser.Dispose();//<-- gets hit when calling .Close(), causing the app to freeze.  works fine without freezing when clicking the "x" button

}

}

[Alex Maitland]

Version?

[Alex Maitland]

Also does your app exit if you remove all calls to `Browser.Dispose`?

`WinForms` will actually call `Dispose` for you, so it's not absolutely necessary to do that explicitly.

On Thursday, 8 October 2015 08:26:02 UTC+10, Tyler Jones wrote:

[Tyler Jones]

If I remove the manual .Dispose() calls, the app still freezes, but *after* the window is closed.  The NuGet package I'm using says the version is 41.0.1

[Tyler Jones]

I just noticed there's a version 43, so I upgraded to 43, and it's still behaving exactly the same way.  If I call .Close() on the form, it freezes.  If I close the form with the "x" button, it shuts down instantly with no freezing.  This happens whether or not I manually call .Dispose().

[Tyler Jones]

Wow, i finally figured this out after many hours.  I was registering a class as my JsObjectForScripting, then calling .Close() from that same class.  If I start up a new Task, then close the window from the new task, it closes with no freezing.  Aparently the problem was because I was closing the form from the same class as the one that was registered as the JsObjectForScripting.

[Jim Shattuck]

Thanks this helped me with similar DotNetBrowser chromium issue.  I ended up using    Task t = Task.Run(() => {Dispatcher.Invoke(//Method that calls _webView.Dispose()}));