Skip to content

WinForms CreateBrowser Forcing form activation

Jump to bottom
Mohammed Osama Mohamed Sayed Ahmed edited this page May 31, 2019 · 1 revision
Windows WS_EX_NOACTIVATE

WinForms - CreateBrowser Forcing form activation #1811

Verify that a task bar button is created for the window (Windows 10)

Run CefSharp.exe --no-activate --off-screen-rendering-enabled

WS_EX_NOACTIVATE was made the default in a7a73dc

To re-enable activation by default then create a custom class that inherits from ChromiumWebBrowser and override the CreateBrowserWindowInfo method. Then it's a simple case of removing WS_EX_NOACTIVATE

from WindowInfo.ExStyle

const uint WS_EX_NOACTIVATE = 0x08000000;

windowInfo.ExStyle &= ~WS_EX_NOACTIVATE;

If there is enough demand then I will add a bool Property that can be used to enable/disable activation. It's not clear that there is enough demand at the moment, most people asking how to disable window activation as it's an unexpected behaviour.

cefsharp/CefSharp - Gitter

  public CefReturnValue OnBeforeResourceLoad(IWebBrowser browserControl, IBrowser browser, IFrame frame, IRequest request, IRequestCallback callback)
    {
        var headers = request.Headers;
        headers["Custom-Header"] = "My Custom Header";
        request.Headers = headers;
        return CefReturnValue.Continue;

    }

  • wpf

Anyone got an answer for my question above re loading a page into the control when the WPF TabItem it is on it doesn't have focus?

@nzmike99 The default WPF TabControl isn't really suitable for hosting a browser, see

The default (WPF) TabControl





When I add the ChromiumWebBrowserWithScreenshotSupport.cs file to the CefSharp.Wpf.Example project it needs the "using GalaSoft.MvvmLight.Command; " dependency which destroys the project with errors

@jeremiahjordani_twitter You could use any Delegate/RelayCommand implementation you like. Pretty common for WPF apps to have one.

If you don't have one then just change the access modifier for the paramaterless TakeScreenshot so it's usable in your instance. The command is entirely optional.

    private void /*Btn*/Sceenshot_Click(object sender, RoutedEventArgs e)
    {
/*
        //CefSharp - Quick and Dirty Screenshot with no class dependency
        MessageBox.Show("Take screenshot");
        double dWidth = (webCefSharpChromiumWebBrowser.ActualWidth);
        double dHeight = (webCefSharpChromiumWebBrowser.ActualHeight);
        int actualWidth = 0;
        int actualHeight = 0;
        actualWidth = Convert.ToInt32(dWidth);
        actualHeight = Convert.ToInt32(dHeight);
        RenderTargetBitmap renderTargetBitmap = new RenderTargetBitmap(actualWidth, actualHeight, 90, 90, PixelFormats.Pbgra32);
        renderTargetBitmap.Render(webCefSharpChromiumWebBrowser);
        PngBitmapEncoder pngImage = new PngBitmapEncoder();
        pngImage.Frames.Add(BitmapFrame.Create(renderTargetBitmap));
        using (Stream fileStream = File.Create(@"C:\SaveFolderName\apollo.png")) //uses System.IO for fileStream
        {
            pngImage.Save(fileStream);
        }
*/
    }

[C#] TakeScreenshot [WPF]

 /*Here is an example that reuses the image that's already rendered to the screen.*/


var template = Browser.Template;
var image = (System.Windows.Controls.Image)template.FindName("PART_image", Browser);
var pngImage = new PngBitmapEncoder();

pngImage.Frames.Add(BitmapFrame.Create((System.Windows.Media.Imaging.BitmapSource)image.Source));

var screenshotPath = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.Desktop), "CefSharp screenshot" + DateTime.Now.Ticks + ".png");

using (var fileStream = File.Create(screenshotPath))
{
    pngImage.Save(fileStream);
}
Clone this wiki locally