CefWebBrowser doesn't show up-Collection of common programming errors

11 years ago

admin

4 minutes

Solution:

This issue is caused by not loading the CefRuntime in the Program.cs. Simply copying all code in the sample file to your Program.cs.

And then if your CefWebBrowser is stuck and having “a spinning wait mouse cursor” then set the SingleProcess = true.

The reason is if the browser is called from a recognized secondary process, the whole process will be blocked until the process is ended.

Question:

Anyone has experience using CEF (Chromium Embedded Framework) in WinForm?

This component has tortured me a whole day. I cannot make it work. It just simply doesn’t show up.

So my question is: how to use CEF in a WinForm application?

I did check the forum, but surprisingly no one asked this question. It seems like I am the only dumb person who doesn’t know how to use it.

public partial class Form1 : Form
{
    private CefWebBrowser cefwbShell = null;
    //private readonly SynchronizationContext _pUIThread;

    private void Form1_Load(object sender, EventArgs e)
    {
        cefwbShell.Visible = true;
        cefwbShell = new CefWebBrowser { StartUrl = "http://example.com" };
        cefwbShell.Parent = this;
        cefwbShell.Dock = DockStyle.Fill;
        cefwbShell.BringToFront();
        cefwbShell.Show();
    }
}

Update:

I am trying to use Xilium.CefGlue. After I copied right version of the release dlls (991) I get an exception:

InvalidOperationException was unhandlled by user code 
   Failed to create browser.

Source: Xilium.CefGlue

Stack Trace:

at Xilium.CefGlue.CefBrowserHost.CreateBrowser(CefWindowInfo windowInfo, CefClient client, CefBrowserSettings settings, String url) in C:\Winston\Knowledge\Projects\xilium-xilium.cefglue-61551ec98ad8\xilium-xilium.cefglue-61551ec98ad8\CefGlue\Classes.Proxies\CefBrowserHost.cs:line 37
   at Xilium.CefGlue.WindowsForms.CefWebBrowser.OnHandleCreated(EventArgs e) in C:\Winston\Knowledge\Projects\xilium-xilium.cefglue-61551ec98ad8\xilium-xilium.cefglue-61551ec98ad8\CefGlue.WindowsForms\CefWebBrowser.cs:line 71
   at System.Windows.Forms.Control.WmCreate(Message& m)
   at System.Windows.Forms.Control.WndProc(Message& m)
   at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
   at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
   at System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)
   at System.Windows.Forms.UnsafeNativeMethods.IntCreateWindowEx(Int32 dwExStyle, String lpszClassName, String lpszWindowName, Int32 style, Int32 x, Int32 y, Int32 width, Int32 height, HandleRef hWndParent, HandleRef hMenu, HandleRef hInst, Object pvParam)
   at System.Windows.Forms.UnsafeNativeMethods.CreateWindowEx(Int32 dwExStyle, String lpszClassName, String lpszWindowName, Int32 style, Int32 x, Int32 y, Int32 width, Int32 height, HandleRef hWndParent, HandleRef hMenu, HandleRef hInst, Object pvParam)
   at System.Windows.Forms.NativeWindow.CreateHandle(CreateParams cp)
   at System.Windows.Forms.Control.CreateHandle()
   at System.Windows.Forms.Control.CreateControl(Boolean fIgnoreVisible)
   at System.Windows.Forms.Control.CreateControl(Boolean fIgnoreVisible)
   at System.Windows.Forms.Control.CreateControl()
   at System.Windows.Forms.Control.SetVisibleCore(Boolean value)

Can anyone help me please?

Update 2:

private void Create()
        {
            var page = new TabPage("New Tab");
            page.Padding = new Padding(0, 0, 0, 0);

            var browser = new CefWebBrowser();
            browser.StartUrl = startUrl;
            browser.Dock = DockStyle.Fill;
            browser.TitleChanged += (s, e) =>
            {
                BeginInvoke(new Action(() =>
                {
                    var title = browser.Title;
                    if (tabControl.SelectedTab == page)
                    {
                        Text = browser.Title + " - " + _mainTitle;
                    }
                    page.ToolTipText = title;
                    if (title.Length > 18)
                    {
                        title = title.Substring(0, 18) + "...";
                    }
                    page.Text = title;
                }));
            };
            browser.AddressChanged += (s, e) =>
            {
                BeginInvoke(new Action(() =>
                {
                    addressTextBox.Text = browser.Address;
                }));
            };
            browser.StatusMessage += (s, e) =>
            {
                BeginInvoke(new Action(() =>
                {
                    statusLabel.Text = e.Value;
                }));
            };

            page.Controls.Add(browser);

            tabControl.TabPages.Add(page);

            tabControl.SelectedTab = page;
        }

I too had problems launching the browser. I could load all the CEF DLL’s, but the browser wouldn’t show up! All I got was the spinning wait mouse cursor when hovering above the control.

Unfortunately I haven’t found the root of the problem, but since the sample project CefGlue.Client works, I simply copied it to my solution instead.

Also, I don’t see how you are initializing the CEF runtime. Have a look in Program.cs in CefGlue.Client how it’s done, but it’s basically this:

    [STAThread]
    private static int Main(string[] args)
    {
        try
        {
            CefRuntime.Load();
        }
        catch (DllNotFoundException ex)
        {
            MessageBox.Show(ex.Message, "Error!", MessageBoxButtons.OK, MessageBoxIcon.Error);
            return 1;
        }
        catch (CefRuntimeException ex)
        {
            MessageBox.Show(ex.Message, "Error!", MessageBoxButtons.OK, MessageBoxIcon.Error);
            return 2;
        }
        catch (Exception ex)
        {
            MessageBox.Show(ex.ToString(), "Error!", MessageBoxButtons.OK, MessageBoxIcon.Error);
            return 3;
        }

        var mainArgs = new CefMainArgs(args);
        var app = new DemoApp();

        var exitCode = CefRuntime.ExecuteProcess(mainArgs, app);
        if (exitCode != -1)
            return exitCode;

        var settings = new CefSettings
            {
                // BrowserSubprocessPath = @"D:\fddima\Projects\Xilium\Xilium.CefGlue\CefGlue.Demo\bin\Release\Xilium.CefGlue.Demo.exe",
                SingleProcess = false,
                MultiThreadedMessageLoop = true,
                LogSeverity = CefLogSeverity.Disable,
                LogFile = "CefGlue.log",
            };

        CefRuntime.Initialize(mainArgs, settings, app);

        Application.EnableVisualStyles();
        Application.SetCompatibleTextRenderingDefault(false);

        if (!settings.MultiThreadedMessageLoop)
        {
            Application.Idle += (sender, e) => { CefRuntime.DoMessageLoopWork(); };
        }

        Application.Run(new MainForm());

        CefRuntime.Shutdown();
        return 0;
    }

You shouldn’t use SingleProcess for production, you can actually leave the multiprocess mode (SingleProcess=false) but need to disable Visual Studio Hosting Process and you wont have problem for debugging (spinning wait cursor)
You never added the control to the form’s controls collection, at least in the samples you showed.