AccessViolationException while taking a screenshot

[marci4]

• What version of the product are you using? Nuget: 63.0.2

  <packages>
  <package id="cef.redist.x64" version="3.3239.1723" targetFramework="net452" />
  <package id="cef.redist.x86" version="3.3239.1723" targetFramework="net452" />
  <package id="CefSharp.Common" version="63.0.2" targetFramework="net452" />
  <package id="CefSharp.OffScreen" version="63.0.2" targetFramework="net452" />
  </packages>

• What architecture x86 or x64? Both x64 and x86

• On what operating system? Win10

• Are you using WinForms, WPF or OffScreen? OffScreen

• What steps will reproduce the problem? In general: Changing the size of a browser and taking then a screenshot from this after the website was loaded again Example: Check out this fork

• What is the expected output? What do you see instead? Expected: The size of the bitmap gets updated when I set the size of the browser. Current: The size of the bitmap differs from the size of the browser and therefore causes an AccessViolationException

• Please provide any additional information below.

  Exception thrown: 'System.AccessViolationException' in System.Drawing.dll
  CefSharp.OffScreen.dll!CefSharp.OffScreen.ChromiumWebBrowser.ScreenshotOrNull(CefSharp.OffScreen.PopupBlending blend) Line 510  
  CefSharp.OffScreen.dll!CefSharp.OffScreen.ChromiumWebBrowser.ScreenshotAsync.AnonymousMethod__1(object sender, CefSharp.OnPaintEventArgs e) Line 544
  CefSharp.OffScreen.dll!CefSharp.OffScreen.ChromiumWebBrowser.CefSharp.Internals.IRenderWebBrowser.OnPaint(CefSharp.Internals.BitmapInfo bitmapInfo) Line 775    CefSharp.Core.dll!CefSharp::Internals::RenderClientAdapter::OnPaint(scoped_refptr<CefBrowser>* browser, cef_paint_element_type_t type, std::vector<CefRect,std::allocator<CefRect> >& dirtyRects, void* buffer, int width, int height) Line 18

• Does this problem also occur in the CEF Sample Application from http://opensource.spotify.com/cefbuilds/index.html? Not tested since it looks like the screenshot wrapper method is doing something wrong! Do you want me to test this anyway?

[amaitland]

As part of #2237 the way rendering for the OffScreen and WPF projects is done has been rewritten, I've run a slightly modified version of your code (OnPaint event is now Paint, there is now a virtual OnPaint method which is more consistent with the other projects). I changed the counter to 100 and it ran through without exception.

The main difference is that the buffer is stored as a byte[] now, rather than a Bitmap, and a Bitmap is only created upon request, this should improve performance and actually greatly simplifies the code.

[amaitland]

Closing this as I'm not unable to reproduce with master, you can try one of the CI builds listed at https://github.com/cefsharp/CefSharp#releases-1 to try it out ASAP.

Will likely be some more changes as part of https://github.com/cefsharp/CefSharp/issues/2237 so subscribe to that issue to be notified of updates.

[gfox1984]

Sorry to ask, but I'm having the same problem (see closed duplicate above). I'm not sure what you did to fix the problem? Do we have to wait for version 65?

[gfox1984]

OK I tested with "65.0.0-pre01" and I confirm the exception is gone, without requiring any change to my code.