We Keep Coding

Hide Child Objects Together with the Parent

I've got a little problem. On a button press I need to open a panel with settings in animation. The thing is when I reduce width and height of a parent object (panel) it does not hide the child objects whatsoever. How can I make the parent object to influence the children's height and width when I change them in the parent?

If these objects are UI elements you can use add a Mask to the panel to hide any child objects that go outside of the area of the panel. As you can see below the square which is a child of the panel object does not render anything outside of the area of the panel.
If you want the UI elements to scale with the changing size of the panel then you should use anchors which will mean that the children of the panel will "anchor" themselves to the positions you set. Here's a short gif to illustrate how it works.
That's with the child image set to preserve it's aspect ratio, if you disable that setting then the box will stretch to perfectly fit the anchors.

If you want to scale your child objects with your parent canvas, you should set your render mode -> world space in your parent object.

Displaying Both VisualCollection and UIElements

I'm using a VisualCollection to display custom DrawingVisuals on a Canvas in WPF, and I also need the canvas to display a couple of UIElements. The problem is that the canvas seems to ignore its regular children when using a VisualCollection. The UIElements don't appear when placed in the VC either.
I want the UIElements to be rendered above the DrawingVisuals, so I cannot (?) place the DVs in an AdornerLayer. Any ideas?

Okay, so I sort of found a solution.
I simply create a new FrameworkElement that hosts all the DrawingVisuals through a VisualCollection, and add this host to the canvas as a regular child.

Dynamically creating textbox and setting its location by pixel

In a WPF application, I'd like to create a textbox dynamically which will show in front of the application and be able to freely set its location by pixel. (The textbox is going to follow the mouse cursor).
This was easily done in Winforms on the fly but WPF makes things.. a little bit weird when it comes to setting a control's location by pixel since I have to add the control as a child of a container. I'm aware this is certainly doable on Canvas, but what I actually have is a dockpanel with a richtextbox to the left and a datagrid to the right.
So what are my options here? Do I have to use canvas? Can I get away with using dockpanel (or grid) to implement what I want here?

You can use a Canvas or a Grid. If you use a Canvas, set the Canvas.Left property and the Canvas.Top property. If you use a Grid, you'll need to set a size for your TextBox, set the HorizontalAlignment to Left, and VerticalAlignment to Top. To change the location of the TextBox, assign it values for MarginLeft and MarginTop.

Place control over other

I am searching a way to put a ComboBox over another Control with xaml. The new combobox should aligned on the right side of the window.
How can I do this?
Best Regards, Thomas

You can use Grid panel. If you do not specify Row/Column of the controls inside the Grid, they will overlap.
Another solution is to use Canvas layout, which is almost like what you have on WinForms, where you can set X/Y of the control and you have more control on where they should appear.

How do I make multiple controls in a Windows Form automatically resize with the window?

I'm new to Windows Forms in Visual Studio, and I am wondering how to automaticly resize controls to the window size.
Say, I have 2 controls in a panel, a List Box and a Button. I want the button to dock to the bottom, and I want the List Box to fit the rest of the space. when the window resizes, the button should be at the bottom (as expected with docking), and the list box should stretch down to the button.
Is there a way to do this without any code?
Thanks.

Dock is pretty easy to use, but I recommend using the Anchor properties instead. Resize your form to a reasonable size in the Designer. Then, place your controls to look the way you want. Then, decide which controls should resize with the form and set the Anchor property as follows:
If you want the control to resize with the form in width, set the Right anchor.
If you want to resize height, set the Bottom anchor.
If you want the control to stay right when the form resizes, unset the Left anchor.
If you want the control to stay bottom when the form resizes, unset the Top anchor.
The problem I have with Docks is that they sometimes act funny when controls are not declared in a specific order, and to get the effect you want, sometimes you have to create extraneous panels just to hold controls.

It really gets messy when you want to maintain the aspect ratio of each control. One way, which is not really up to the mark if you want to get into fixing the details, is to use TableLayoutPanel and use Dock and Anchor wisely to achieve what you want.

Use the dock and fill options on the controls. Look under properties for each object, and containers if they are in any.

You can use SplitContainer
Google for examples. Here is one

Try setting your ListBox's Dock property to Fill.
You'll need to watch for one thing though: by default the ListBox will size itself to display whole list items. If you resize the control so that it displays a partial item it will adjust itself so it will display a complete item. This can make the control appear to lose its 'Dock'ing behavior. The solution for this is to set the ListBox's IntegralHeight property to false, which specifies that the control not resize itself to fit complete items.