I have a WinForm that uses an ElementHost to display a WPF UserControl. Once every 50 times or so when the form loads the WPF content fails to paint. You can see through the WinForm chrome to whatever is beneath. Resizing the window gets the WPF content to show up.
Is this a known issue? Can anyone suggest a workaround?
We have fought these types of issues before. See this WPF forum post for more info on our particular flavor (I don't know if it is the same issue or not).
The only thing that we found to work was to change the size of the ElementHost.
_elementHost.Width++;
It's a complete hack, ugly, and I'm embarrassed to even post it. But nothing else ever worked for us. So, it is definitely a workaround. (Grin)
We tried Invalidate, Refresh and everything we could think of ... on the ElementHost. We also tried InvalidateMeasure, InvalidateArrange, and InvalidateVisual on the WPF hosted content. No luck.
If you find another way to fix your issue, I would love to hear about it.
Good luck, I know I have lost some hair on this one.
Update 1:
I have submitted another WPF forum post on this. Maybe we can get a response from Microsoft. Sure seems like a bug to me.
Update 2:
After I fixed the refresh issue with the above hack ... I still had another problem to solve that I thought worth mentioning here. That is: there was a definite delay until the screen refreshed. This made it seem like the user was navigating to another screen (it wasn't ... it was just the contents of the double buffering buffer). I ended up having to manually call System.Windows.Forms.Control.Refresh() on the Control that was hosting the ElementHost. In this way, even though the pause was still there ... at least the screen was blank ... and it didn't look like the user was navigating somewhere ...
the following worked for me.
On the Form_Activated event, I added the following
elementHost1.HostContainer.InvalidateVisual();
I know this post is old, but in the later version of .net (i.e 3.5), you can try to use software rendering mode. This seems to fix a lot of problems when you host a WPF control in the ElementHost.
Ref: Software rendering mode - WPF
Maybe call Invalidate on the ElementHost?
Have you tried to use reflection to see the code behind _elementHost.Width++?
Related
i programmed an application using C# WPF now it works fine on my machine when i debug and also when installing but it doesn't work like it supposed to work on some other machines , some of them accepted my exe file and worked just like i designed and some of them made the textboxes and labels not aligned probably and the text of the buttons also changed a little not like as i designed and they look horrible but the logic and inside programming works fine but the design is just so horrible for the user and not like i designed
P.S : this is from the design perspective , NO ERRORS!
i'm not sure what you guys are so confused about his question.... if you don't know the answer just say u don't lol
anyways the first thing that comes in my mind is maybe the control's borders change and that changes the position of other controls?
try to set ur controls width and height on auto and see if that helps + u can try play with ur control's margin a little.
This is a scenario when usinf RowDefinitions and ColumnDefinitions really shine. I would suggest doing this since you are having issues with the UI not displaying properly on all deployed machines.
My first post here so here goes,
i have a UserControl with about 30 controls (labels, textboxes etc).
Now i would like to make a "screenshot" of it.
So i used the "DrawToBitmap" method from the UserControl.
Here some samplecode
//this is the UserControl with the about 30 controls
var sampleusercontrol = new SampleUserControl();
var bmp = new Bitmap(sampleusercontrol.Width, sampleusercontrol.Height);
sampleusercontrol.DrawToBitmap(bmp, sampleusercontrol.Bounds);
if i run this code, it returns me a black image all the time.
I have no clue why. Please help!
Edit:
Forgot to say that the UserControl is a WinForms UserControl
This had been working for me for years until it started returning a black image last week in production. Interestingly, it was just after we applied a new windows patch. I was able to find this posting about the issue:
KB3057839 Has Broken Windows Forms Control.DrawToBitmap() When Called from Application Launched From Windows Service
You didn't mention how that winforms control was being created, but in the first case it was from a winforms app launched by a service. There is also a case on the Telerik site where the control was instantiated server-side by IIS to create a PDF file:
http://www.telerik.com/forums/export-to-pdf-597e04c01b39
Try checking for the patch KB3057839 and rolling it back for a short term fix. Hopefully Microsoft will respond with a fix or a workaround going forward.
I had the same issue. The latest round of ms patches corrected the issue.
Check that the control has been loaded.
I was struggling with this, but it turned out the control was in another tab and wouldnt display correctly until I had clicked on the tab, then run DrawToBitmap.
I have a web browser control embedded in a tabPage in my application. How do I drag it out of my desktop app, that is an option to dock/undock or unpin it.
Edit: After reading a bit, I think I should do this with DragDrop events. I saw several examples to drag and drop within an application or between applications, but I am wondering if it is possible to drag the control outside my application to another screen. Should I record the screen coordinates to do this?
Edit: So far I have tried to capture MouseUp/MouseDown events with a simple button control but that only helps with moving the control within the form.
When I was reading DragDrop documentation in MSDN, it says 'AllowDrop' needs to be set to the target. But my target is not limited to a form it can also be a desktop screen. It makes me think I am totally on the wrong route. I am not pasting any code because I believe I am looking for an approach or some suggestion to do this. I am a novice so if this is not clear, please ask me further questions.
Hoping to hear from someone.
Thanks!
If anyone is interested, this codeproject link helped me get started:
http://www.codeproject.com/Articles/15418/PullApartTabPage-Docking-and-Undocking-Your-TabPag
I'm trying out the Telerik controls, specifically the RibbonBar/RibbonForm and am running into a weird issue. In design view everything looks fine, like this:
But when I run the form everything on the RibbonBar is gone, looks like this:
Anyone have experience with these controls or have an idea why this is happening?
Have you tried adding Groups (and maybe even a button or two) to some of the tabs? In the first screenshot, the View tab doesn't have any groups. Perhaps Telerik is not expecting an empty tab and so doesn't behave quite like you'd expect at runtime. I would also check that you're using the latest version of their control - perhaps it's a bug they've fixed recently. Finally, I'd try going through their 'Getting Started' page to see if there might be a step you're missing.
For some strange reason, my toopltip in the VS 2008 C# winforms application shows up behind the form! It's very frustrating and I can't figure out what I should do. Anyone face this before? Ideas?
(PS - I'm doing a toolstip.show programmatically within the form)
There are a few things you might want to check:
Make sure the tooltip knows what its parent window is.
Make sure the window the tooltip belongs to is in the foreground (no, this isn't a requirement for displaying tooltips, it just helps debug.)
Try giving focus to the owner of the tooltip. If that fixes the problem, then there's probably an ownership problem with your tooltip.
Try bringing your page element to the front. (Right click on element, bring to front). Is this happening on all tool tips you have configured? And no, I have not seen this before
There is a similar (and known) problem with tooltips appearing behind the Windows task bar. The problem is sporadic and I have never seen a solution. If you're also seeing this behavior sporadically (and I suggest that you try this on different machines), then it may be related. Otherwise, if the problem is consistent across multiple machines, let's see your code, because you're probably doing something wrong.
I have a similar issue. I have a user control written as C++ WTL, being used in a C# .NET2 app. If the control is just on the form then the controls tooltips work fine, however if the user control is on a panel or in a group then the tooltip is behind. I've tried changing the WTL code to force the tip to the front, this works but causes issues with lost focus/selection in other controls.
This problem is almost always caused by the window being TopMost. Try using SetWindowPos to set your tooltip to HWND_TOPMOST. I haven't tried this though...
I've seen this issue happen in both Windows.Forms and Delphi (native windows) based applications, caused by the interaction of "stay on top" with the Windows API.
Essentially, marking a form as TopMost makes it stay on top of some windows, but not others - Window management has more than two distinct levels.
What I found is this: my applications would behave themselves when run normally, with tooltips showing on top. Problems would occur when switching to- and from- other applications - somehow the "TopMost" of the windoww would become "very-ultra-top-most" (non-technical term ;-) ) with the tooltips appearing behind the window.
Having described the problem, I'd like to offer you a solution - but I never did find a good one. Sigh.
Hope that the additional information will be enough for you to find the solution you need.
I have seen this happen on Windows XP, particularly on the taskbar.
Are you sure it's an issue with your application, rather than the OS?