I've created a WPF application which has a Canvas on which I place UserControls which are moveable and resizeable by the user (just like a Windows-Window). Now I have detected that this can be very slow on older PC's which is a problem.
As a solution I thought about generating a graphic showing the UserControl and show this while resizing/dragging the Control, to prevent WPF from recalculating all Elements permanently. The only problem is that I have no idea how to generate this image.
Is there perhaps something like a function which does this in .Net? Or how could I do this on my own?
You can render a WPF control to a bitmap using RenderTargetBitmap, then this image can be copied to the clipboard, saved to a file, or used as part of your GUI
Check out Get a bitmap image from a Control view
Beware with this that you can hit problems when parts of the control you are trying to render are not visible (within a scroll viewer perhaps)
WPF applications really do require some fairly serious grunt; particularly in the graphics department and benefit greatly from having a decent video card present in the system. Even then the performance of WPF apps (if not carefully constructed) can leave much to be desired...
That said, you could feasibly use FixedDocument to rasterise a UserControl, and then convert this into a GIF/JPG/PNG and put this in place of the control being resized... however I would expect that process itself to be as slow or slower than your current observed performance issues.
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I need to rotate my custom control in Windows Form using C# without using third-party libraries.
Don't want to either rotate the text or image of control instead actually need to entirely rotate control.
From here:Is it possible to rotate a button control in WinForms?
5 up vote accepted
You can't rotate controls. That's simply not supported by the native API controls that WinForms uses.
And one might wonder why it even should be supported. What could you possibly be trying to do that you'd need to rotate a button control? It would be much easier to draw it in a different place with a different shape in the first place, rather than trying to rotate an existing control. (Do note that you can also resize and reposition a control at run-time, if that would fit your needs. Investigate the Size and Location properties.)
The only workaround is to draw the control's image to a bitmap, hide the control, and draw the bitmap onto the form in the location you want it to appear. Of course, that won't result in a control that the user can interact with. They won't be able to click an image of a button, because it's not a real button. If that's acceptable to you, you should probably be using an image in the first place, rather than a button.
It is possible if you can get control of the painting, but you have to do a lot of the work yourself. Basically it all occurs on painting. A good example demonstrating how to do it is the Dock Panel Suite for WinForms.
In the VS2005AutoHideStrip (found here), there is a GetTransformedRectangle method that uses a System.Drawing.Drawing2D.Matrix class to rotate a rectangle.
It also sets the Transform property on the Graphics class, which will apply transformations automatically when you ask for something to be painted.
I advise reviewing this code for examples, it does it to draw docked tab strips down the sides of the page as opposed to top / bottom.
Some controls like TextBox are funny in that they borrow heavily from low-level Win32 libraries in their painting / behaviour, I've no idea if it is possible to get enough control to rotate this.
It is not possible to rotate controls. This is not supported by WinForms' controls API.
As you are dealing with a custom control, try simply redrawing it to suit your purposes.
I am pretty sure you can not perform this in windows forms at least not easily. However you can perform this in WPF and then bring WPF to your windows Form if you are looking for cool designs or even special effects to your controls.
This is FAR more easily done in WPF. In Windows Form, it's a huage pain to pull off.
Hope this help
I'm writing a program to implement COM component in C#. This component provides a UI component too. In the interest of making it easy to implement future additions to the component, I decided to write the UI in Xaml using WPF and wrapping it in an ElementHost control to provide the handle back to to the COM consumer.
Here's where this gets interesting. The element is being hosted in a win32 tab control. The first time the tab is selected, it loads fine. Switching to another tab and coming back causes it to not draw the component correctly. If I move the mouse through it, it'll draw the TextBox elements, but it'll never redraw the whole UserComponent.
I've tried every possible solution I've seen suggested, from changing the height/width values of the component to putting the HwndTarget in SoftwareOnly rendering mode.
I'm not sure what to try at this point, so suggestions are welcome. I'd really like to do this without using Windows Forms as the future maintainers of this aren't the best programmers and it's a lot easier to tell them to write up a Xaml file with data bindings than manually lay out a form and set the values in the code-behind.
Haven't met such problem yet.
Try to force refresh or focus (methods) to the hosting wrapper or HwndSource when switching to the hosting tab.
I've created an WPF based application showing me thumbnails of external windows. As an example i pick up icq, firefox and some other windows, create thumbnails of these and render them onto my WPF based application.
That works fine already and looks like this:
http://img560.imageshack.us/img560/1170/oijoijio.jpg
(Just showing one thumbnail in here, but there will be multiple in future)
The WPF application will also contain some controls to actually select the windows being "thumbnailed" and a few others.
The next step and my actual question is about how i would redirect these content being rendered into a Bitmap instead of the "WPF window" itself.
Is there a way to accomblish that goal? All the windows content (WPF containers and the drawn thumbnails) need to be rendered into a bitmap which i can display in directx window being owned by a game.
I know that it is possible todo that somehow, as a programm called overwolf also uses WPF inside of their application. They actually install device inline detours to hook into the rendering process of the game, where they render their wpf content. I am not sure if they use some kind of bitmap they render in there, or if they directly render the wpf content onto the dx-surface somehow.
Other ideas besides the bitmap based style i plan to go for are welcome aswell!
Thanks for your reading until here, and another big hug for any answer :)
Any WPF Visual object can be rendered into a bitmap using RenderTargetBitmap.
When the user clicks a button in my C# app I want to show him bunch of images so that he can pick one. I don't want to do it with file browser, I want him to be able to view little thumbnails of the images so that he sees what he is picking.
Is there any control I can use to do this?
Thanks
If you are refering to a WinForms control, I would recommend the free ImageListView control.
Works very well in my own real-world projects. Plus, the author is very responsive and the control seems to have a very high overall code and design quality.
You will need to create custom code. Or you can use a WYSIWYG Editor.
Here are 2 popular ones for .NET.
http://www.tinymce.com/
http://ckeditor.com/
Create multiple PictureBox-es in a grid formation in the form that you are creating.
Display one thumbnail in each PictureBox.
I am usually against PictureBox control usage, but in this case, you can't miss.
I have a WPF application (.NET 4) which has a main window, and inside that main window shows many smaller UserControls. Various actions performed by the user cause the UserControls which are displayed to get replaced by different other controls with different data.
I am running into performance problems however, when switching these controls. The WPF dispatcher thread goes to 100% CPU while loading controls. On older machines, or with larger numbers of controls, this can result in the application appearing to lock up for as long as 30 seconds!
Profiling indicates that almost all of this CPU time is spent calling the various InitializeComponent methods of all the different UserControls - no one control appears to be vastly worse than any other, they all seem to take between 0.2 and 0.5 seconds (on my dev machine with a fast processor and good graphics card).
As far as I know, InitializeComponent is where WPF actually loads the compiled xaml into memory.
I'm at a loss for what to do here. I'd like to pre-initialize things on a background thread, but all WPF controls must be created and used on the dispatcher thread, so I don't think this is possible.
Otherwise it looks like the only options I have are to delete all my xaml??
Any help would be greatly appreciated
To revisit this - we do have many complex controls on the screen, but we can't just get rid of them to keep WPF happy!
Further experimentation with profiling showed that using Custom controls (basically just a C# class deriving directly from Control and defining the UI in a Generic.xaml themes file only seem to incur the hit of loading and parsing the XAML once. Thereafter, each control just applies the pre-existing theme.
Custom controls are much more difficult to work with than UserControls, but this did seem to help our load performance a lot.
The InitializeComponent method takes time because it needs to insert the control in the Visual/Logical tree and assure all bindings, themes, expected resources etc.
My only suggestion is - is it possible to initialise all potential controls from the outset, and then show/hide them when needed using the Visibility property ?
You can use Freezable for caching some UI, but if they are user controls then most likely you will want your user to interact with them.
For the record, I had a window with a load time about 1500 ~ 2000 ms, the problem was the icons.
I was using a tool for converting SVG to XAML DrawingImage elements, and a user control with a large resource dictionary with a drawing image for every used icon
The InitializeComponent was so slow because it had to parse that large XAML file containing all the vector data for the images
Hope it helps.