WPF - UserControl sizing on Custom Canvas - wpf

I have a custom canvas that I can drop controls on, move, and resize. I need to be able to at least start with a pre-determined size but then allow re-sizing.
My problem is that I have a user control that doesn't appear to resize. I set Height and Width on the user control (works on drop). But then as the control is resized on the canvas the visual size stays the same (the sizing handles are changing). I can see the Height property changing (usercontrol.height) as the control is resized. But again, the appearance of the control stays the same size.
I had a thought that the inner container on the user control should be bound to the usercontrol.height but that didn't seem to help. (or maybe I didn't have the binding right).
On the same canvas, if the dropped control is for example, an Image control, I can set an explicit height on the drop and everything resizes as it should. So it seems to be UserControl thing.
So is there something special I need to do with UserControls to get the visuals to resize? Should I be using explicit height and width to get it all started?
Thanks for any help.

The WPF layout system can be confusing, as you've discovered. There is no substitute for a solid understanding of the layout and measurement system. If you plan on doing much WPF development, it's worth taking 20 minutes to read this article on the layout system and then experimenting for a while in an iterative environment such as Kaxaml until you feel comfortable.
The system is very logical. It won't take long for the penny to drop. Sorry for the indirect answer, but I don't believe there's enough information in your question to really explain what's going on.
You might also look at the HorizontalAlignment and VerticalAlignment properties.

Not a WPF expert but I believe you need to enable auto-sizing in order to achieve the scenario you are looking for. This is done by setting the Height/Width of a control to Double.NaN which essentially says, "I have no specific size". Once you do that, the control should resize to occupy available space based on the need of the control.

Related

XAML: How to set controls properties depending on screen resolution?

I'm developing WPF application (.NET 4) where I have few UserControl's which looks pretty good on most of the screens.
But now customer have new monitors where some elements are too small. The best solution we found is to make some elements smaller, to left more space for the main panel.
The layout is now pretty complex, and I spend a lot of time to find which margins, heights, widths and so on.. I need to change to implement this.
Usually it is some children elements Height, Width +-10 or so. Sometimes Margin. And in one case it's Style's Setter Property="Width" which defined in Resources.
I'm wondering is it possible to make this changes configurable, so for my specified screen resolution (let's say I know only that Width=X and Height=Y) they was applied, and for all other screens it stays the same as now?
How to do this using as less code-behind as possible?
I like the solution with VisualStateManager and VisualState.SateTriggers, but looks like my application does not recognize this.
When you are using user controls inside the window may be you could set the height and width of the grid's row and column definition to '*' and also make scroll bar visibility of horizontal and vertical scroll bar to auto.
Hope it helps you.

Sizing WPF windows automatically

When designing WPF dialog windows in the XAML designer (that are not manually resizeable by the user), the windows automatically resize to fit their content, and everything is fine. But when I run my app, the windows become huge and there's a lot of empty space.
I know this is a "feature" of WPF that can be "fixed" by setting the SizeToContent tag, but another issue arises when I do this: If the window contains a textbox, for instance, and the user enters data that overflows the visible area, the window will stretch to accommodate it. This happens with listboxes, treeviews, you name it.
All I want is for Visual Studio to figure out the ideal window size that it shows me at design time, then set the window to be that size at runtime, and don't change the size after that. It seems like this should be an easy thing to do.
Edit: Figured out part of the problem: I have controls set up in a grid, and the column's width is set to "Auto" which is why everything is resizing.
Use View Box
The ViewBox is a very useful control in WPF. If does nothing more than scale to fit the content to the available size. It does not resize the content, but it transforms it. This means that also all text sizes and line widths were scaled. Its about the same behavior as if you set the Stretch property on an Image or Path to Uniform.
Although it can be used to fit any type of control, it's often used for 2D graphics, or to fit a scalable part of a user interface into an screen area.
<Viewbox>
<Enter your code/>
</Viewbox>
Try setting the window's height and width to Auto. Also, remove the SizeToContent attribute. This should fix it.
I do not think that this is this is something which is commonly requested so it's probably not easy to do, one method i can think of would be starting with automatic SizeToContent and handling the Loaded event and setting:
Height = ActualHeight;
Width = ActualWidth;
SizeToContent = System.Windows.SizeToContent.Manual;

Scale usercontrol in wpf ? vertical and horizontal scrollbars

I implemented a usercontrol, but i have a problem with rescaling the window. I know when i make the window smaller, everything scales, and every textbox and label becomes also smaller. But this is not what i want, i just want that when i make the screen smaller, everything stays the same size, and that scrollbars appear ( vertical and horizontal ). How do i do that?
Thanks
Assumption
The behaviour you describe, is not mandatory the default layout-behaviour of WPF. It depends on the layout-controls you use. I assume, you're using a Grid with setting it's columns and rows to the Start (*)-GridLengths. This would have more or less such an effect as you describe (without scaling). Or maybe you are using a ViewBox, this control scales the whole content based on the available layout size.
Solution
I guess that wrapping your whole content into a ScrollViewer will probably do what you desire. If not, I suggest that you post some XAML-code to show us how you have built your content.
<ScrollViewer>
<YourContent>
</YourContent>
</ScrollViewer>
Update
If you really scale your window (applying a ScaleTransformation) and you want your UserControl to be the only control within that does not scale, you have to scale your UserControl in the opposite direction as you have done it with your window. Apply a ScaleTransformation and set the scale values to 1/scale. Or try to use the ViewBox to blow up the content of your UserControl, but this will not be very exact.

Why isn't always possible to set a winforms dimensions?

I'm trying to size a checkboxlist control to 500,250 from its current 502,251 (It's an OCD thing) but every time I try, it just reverts to 502,251.
Is it because the parent container is docked in the window? Are there any workarounds?
(This is through the visual designer)
Most likely the control is being resized due to the control's font size. The ListControl does not like to display an item that will be "split" by the bottom edge, so it will resize the height. Try changing the control's font size and adjust again to verify.
No work around, and you really do not what one, because the control is really doing the right thing.
Yes, it is OCD. I have it also, but this one you have to let go. :O) Consider yourself lucky because you are only one or two pixels off. I was five pixels off once, and I had to put a note on my monitor to ignore it. It so bothered me.

Is there a way to automagically make a canvas scroll on overflow in WPF?

Been checking the web and this site, but couldn't come up with any descent results.
Is there a way to make a canvas in WPF show scrollbars on overflow ? Been trying the scrollviewer, but can't get it to work :(
Thanks in advance..
The problem you're running into is that Canvas, unlike many WPF panels and containers, does not size to contents. That means if you add an element which goes outside the canvas boundaries it will not update it's size. Hence embedding a Canvas in a ScrollViewer will do no good unless you manually update the size of the Canvas.
It sounds like what you want is a Canvas which supports size to contents. This blog entry has exactly that control.
http://themechanicalbride.blogspot.com/2008/11/auto-sizing-canvas-for-silverlight-and.html
I took a different approach and abandoned the Canvas for Grid. The Canvas is more performant but for my purposes at least I haven't noticed a difference. The grid can mimic the behavior of canvas by doing the following.
Create a single row,single column grid.
Set the HorizontalAlignment to Left
Set the VerticalAlignment to Top
Use Margin "x,y,0,0" to set the position.
Bam..works just like canvas and it works great in a Scrollviewer.

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