Logo
My Account |  Site Map | Contact Us  
Welcome Guest Search | Active Topics | Sign In | Register

Downloads freezing up Options
Allen Howard
Posted: Tuesday, August 3, 2021 3:59:19 PM
Rank: Newbie
Groups: Member

Joined: 8/3/2021
Posts: 3
Hello.
I have a EO.WebBrowser.WebView that seems to freeze when downloading. It doesn't happen in patterns. It will go along and download a dozen, but then sometimes the first one will download fine, then the second or subsequent file will not download.

Someone in this forum mentioned destroying the webview when I'm done downloading. That seems to help, but it still hangs up.

In one post, someone suggested to trap for the DownloadUpdated event and call e.Item.Cancel();
However the DownloadUpdated event never fires.

I saw another post which says, "If the server does not send the total size of the file, then the browser engine can not calculate the progress thus it does not trigger DownloadUpdated event."

We are downloading PDFs from a county government website, so their server may not be sending the file size...

So how can I cancel a download if it's obviously hung up?

eo_support
Posted: Tuesday, August 3, 2021 9:38:29 PM
Rank: Administration
Groups: Administration

Joined: 5/27/2007
Posts: 23,072
Hi,

I am not exactly sure how you start the download or whether you receive BeforeDownload event. Regardless, the basic idea is to see if you receive DownloadUpdated event within a certain amount time (for example, 1 minute) after the download starts. If you do not receive DownloadUpdated event within that time frame, then most likely it hung somewhere. In that case you can destroy the WebView and recreate it. There are several different scenarios as to determine when the download starts:

1. If you receive BeforeDownload event, then you can use that event to determine when the download starts;
2. If you start the download programmatically, then your code would know when the download starts;
3. If the download is triggered by user clicking a link (but you do not receive BeforeDownload event), then you can write additional code to check BeforeResourceLoad event to find out when the download starts;

Another thing you want to check is how many concurrent download you already have. Chromium like all browser has an internal limits on how many connections per server. When that limit is reached, the new download will not proceed until a connection is "freed".

Whether the server sends back the total size does not impact download jobs. It only makes it impossible to display download progress. However it should not prevent the download from starting.

In any case, it would be very helpful if you can find a way to reproduce the problem. This is the only reliable way to get to the bottom of such issues. Otherwise we would all be shooting in the dark and it is unlikely we will hit any meaningful target.

Thanks!
Allen Howard
Posted: Tuesday, August 24, 2021 10:06:43 AM
Rank: Newbie
Groups: Member

Joined: 8/3/2021
Posts: 3
Allen Howard
Posted: Tuesday, August 24, 2021 10:07:16 AM
Rank: Newbie
Groups: Member

Joined: 8/3/2021
Posts: 3
Thank you. I simply call WebView2.Download(PDFFile, DestFile);
WebView2 is created in WebView1_NewWindow() because the javascript link that gets us to the page forces to open in a new page.
The BeforeDownload event never fires.
The code works most of the time, but occasionally it hangs up.
eo_support
Posted: Tuesday, August 24, 2021 7:09:00 PM
Rank: Administration
Groups: Administration

Joined: 5/27/2007
Posts: 23,072
Hi,

You can try the steps we outlined in our previous reply. And if that still does not work, please try to isolate the problem into a test project and send the test project to us. See here for more details:

https://www.essentialobjects.com/forum/test_project.aspx

Once we have that we will debug it here and see what we can find.

Thanks!


You cannot post new topics in this forum.
You cannot reply to topics in this forum.
You cannot delete your posts in this forum.
You cannot edit your posts in this forum.
You cannot create polls in this forum.
You cannot vote in polls in this forum.