In a WPF application I have a user control that hosts a win forms RichTextBox control using the WindowsFormsHost. The user control is used in a panel that is made visible at a certain time. The problem is that the forms control is displayed a few moments before the containing panel. I tried delaying the display of the RTB until the panel is shown, but then the UI freezes for 2-4 seconds when the forms control is loaded. Please help if you know a solution to make the control load faster. Thanks!
You should use a profiler to see where most of the time is consumed, have a look here: What Are Some Good .NET Profilers?
I managed to find a solution for this :) Actually, the WindowsFormsHost had a Transparent background set, and just removing the transparency solved the performance problem.
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I'm making C# application design with images, but when I launch it, I see loading images (~1sec), so how to make simple loader, when images (background, logo, etc..) fully loads, to show my app? I know it's possible but I don't know how to. Thanks so much!
This sounds like standard behaviour. The controls get painted one by one in z-order and if one is slow the rest may appear to flicker.
You could try double buffering the whole form as shown here:
How to fix the flickering in User controls
Alternatively you could suspend the layout while everything is drawn and resume it afterwards:
How do I suspend painting for a control and its children?
i have create a few WPF applications in visual studio, and now i would like to create a final application to run all of the created apps in the final application. i would like to know how i can create a layout that displays the apps that are running inside the final app as buttons that can be clicked and cause the app to expand and allow the user to work on that app and then when finished return back to the final app and see the other apps to choose from. I imagine it would look like a Google chrome blank page that allows you see your familiar webpages and click on them to load them up. Any help or advice on what i should focus on to implement this would be much appreciated.
Thank you for taking the time to read over this.
Consider using a VisualBrush this takes other WPF UI (your "apps") and uses their UI as a brush for another UI element.
Raj Kumar has a simple article called Visual Brush in WPF for details.
The bit you probably want is at the bottom where he shows you rendering a controls content in another control. The magic being binding the controls visual to the element name whos UI it should render.
When I fix a Background to my winform, It is getting blink on form load. I have a table layout panel on my form and I kept all my controls on the table layout panel.
I set the backcolor of tablelayout panel to Transparent and Set the Image to the background. Why am I getting blink on my form load?
WinForms doesn't handle transparency very well (As I'm sure you may have noticed, not all WinForms controls even support it). The blink is caused because as your TableLayoutPanel is loaded, as well as all its items, the Form has to find the correct 'image' (Because the control doesn't support transparency in the same way as WPF or a game does, it instead uses an image of the controls behind it) to display. It must go through this process as each of your controls are loaded, hence the blinking. You can try enabling DoubleBuffering on your Form, however, if I recall correctly, this can cause issues with transparency.
If you find that you are using a lot of transparency and/or want to customise your Form a lot more, I suggest you take a look at WPF. It offers far greater control over your Form (Window in WPF) as well as supporting transparency on every single control.
I have a similar problem to this question regarding painting of wpf controls
The application I work on is a rather large Windows forms threaded application with several wpf user controls throughout the application. The problem occurs in a plugin of the application where a third party c++ library is called on a separate thread, WndProc is overriden to get the progress updates from the third party library. I have yet to determine the exact scenario that causes the problem but similar to the above mentioned question, after a few runs the wpf controls fails to paint and update.
Setting the width of the elementhosts does solve the painting issue for most of the controls but after this all the wpf controls in the application seems to become 'unresponsive' - visually... the progress bars fails to show progress (though the value does change), scrollbars does not respond, selecting an item in the listview does not highlight it(it does get highlighted after resizing and it does actually get selected - you just can see it is selected) the treeviews does not paint after the resizing, it only shows a black background where the treeview should be (though when I click on the items where they should be in the treeview, the events does get trigerred)
I know I should probably find out the root of the problems that causes this first (its hapening rather randomely and is hard to trap) - allthough putting a breakpoint in the WndProc method does seem to cause it to fail on a regualar base...
What I was hoping for is a way to 'reactivate'/refresh all the other controls throughout the application... I am an intermediate wpf, c# developer and dont really know enough yet about the messaging and events that happens in the background to use them effectively ... my thought is that some event or message that tells wpf to redraw must be broken or interrupted or something - how can I determine what is broken and maybe reactivate it??
Any advice will be much appreciated...
Thank You
It could be that the event that causes the WPF control graph render is never being processed because of that WndProc override.
Since you are inter-oping with WinForms, you can force the events to process by performing a call to Application.DoEvents(); somewhere. Perhaps after you update the progress bar.
I have a form that contains a lot of runtime generated controls (image, button, panel,...), about 100 controls (I'm making a card matching game so there is a lot of controls in the form).
I place the generating code into the constructor and each time the app starts, it took about 3-5s to load all the controls completely.
If I bring another window on top and then back to my app, the controls will be redrawn again.
How can I prevent the controls from being redrawn? If you don't mind, please give me a simple example in C#.
Any help is appreciated!
I found this article that explains how to do this in .NET by calling the WIN API SET_MESSAGE function to set the WM_SETREDRAW flag for the control you do not want updated. Although you can stop certain controls from updating, are you sure you can't approach this issue by reducing the number of controls on the page? 100 Controls seems like a lot and may be an indication that you need to have multiple views.
Enjoy!
My suggestion is to use the form as a drawing surface and draw your card bitmaps directly onto the form. Its not hard to do.
You can add a handler to the form Paint event which will give you parameters with a Graphics object. Use graphics.DrawImageUnscaled to draw each card at the location you want.
This will make the app much much faster.
Preventing a control from redrawing is fairly pointless. You'll get a hole where a control was supposed to appear, your user won't have any use for that hole.
It redraws slowly simply because you have too many controls. You can only get it to redraw faster by using less controls. Or by using controls that can display multiple items in one window, like ListBox, ListView, TreeView, DataGridView.
Note that your specific issue is fixed in Vista and Windows 7. The Aero theme uses off-screen buffering for windows. Which means that windows don't need to repaint themselves anymore when they are obscured by another window. You will however still get slow redraws when the user minimizes the window and restores it.
You might want to consider using a single data table control. A ListView (or something like ObjectListView) may be a good option.
If your data isn't really a list/table, you should split the controls into separate tab pages, which would improve both performance and usability.