One could create a control by starting from a container control (like panel) and add other existing controls (like buttons, textbox, etc) on it. But in some cases, there are no such suitable primitive controls and one has to draw things from scratch.
Avalonia UI's Visual Studio extension has a UserControl template, and it seems that it allows adding existing controls using XAML, which is the former case of the previous paragraph. But how to draw from scratch? Where is WinForm's OnPaint() equivalent or WPF's OnRender() equivalent? Is there any example of creating a control from scratch in Avalonia UI?
or WPF's OnRender() equivalent
It's called Render, the name is pretty much the only difference, DrawingContext's API closely resembles WPF one.
Related
I am working on a project with MDI forms. My problem is when I open an MDI child borderless form. For a moment I see this...
and then appears to be OK...
Any idea what can cause this?
Note that title bar and bottom bar is custom controls. FormBorderStyle is none!!!
Windows doesn't actually support changing the border style for MDI child windows. The operating system lets you do it, but it is an unsupported configuration and quite likely to be buggy.
WinForms is supposed to insulate you from these types of concerns, so this is really a design flaw. It should be throwing an exception when you try to modify the FormBorderStyle property of an MDI child. Implementing MDI support probably wasn't Microsoft's biggest priority. It was essentially dead even when WinForms was first released way back in 2001-ish. The entire MDI paradigm is no longer supported, and no longer recommended for use in software.
As you've seen, you can hack it so that it kind of works. But you get this flickering effect because Windows is trying to draw the non-client area that is supposed to be there.
Two better ideas:
Stop using the obsolete MDI paradigm and find a different, more user-friendly way to implement your UI. For example, separate, top-level forms. Or a series of tabs.
Stop using ugly custom "skins" that break with the operating system's standard visual appearance, cannot be customized or disabled by the user, and tend to be buggy.
If you absolutely have to do this, and want to make it look good, then you will essentially have to re-implement the MDI paradigm yourself. Create a standard form that will serve as your de-facto parent. Then, instead of using MDI child forms, you will use a series of UserControl classes (or a Form with its TopLevel property set to False). Then you can remove the system-drawn border, allowing you to draw everything yourself. The UserControl objects will then be displayed as children of the "main" form, just like any other control would be. So far, so good. Now, the ugly part is that you'll be responsible for managing these children yourself: showing them when necessary, hiding them when necessary, allowing the user to drag them around within the "main" form, logic for "maximizing" and "minimizing" them, etc. You'll have to write your own code to do that. I strongly recommend against it; getting this type of thing right is going to be rather difficult and of dubious value once you get finished.
I hear RelativePanel and SplitView are new layout controls for Windows 10. What is cool about the RelativePanel put as concisely as possible?
UWP is more focused on making a single app which will run on all the platforms. These panels are also called as Adaptive Panels. It has taken care of Adaptive UI very beautifully in app development.
RelativePanel is better than StackPanel to implement the desired layout for multiple screens using the same base code.
It has attached properties eg. RelativePanel.Below, RelativePanel.Above, RelativePanel.RightOf, RelativePanel.LeftOf which is very useful for making the different UI for different Device family using the same code.
RelativePanel is even more powerful when it is combined with VisualStateManager. You can see the example here.
MSDN has all the answers but here is a summary as concisely as
possible.
RelativePanel defines an area within which you can position and align
child objects in relation to each other or the parent panel. It is
essentially a layout container that is useful for creating UIs that
do not have a clear linear pattern; that is, layouts that are not
fundamentally stacked, wrapped, or tabular, where you might naturally
use a StackPanel or Grid. If your UI consists of multiple nested
panels, RelativePanel is a good option to consider.
Using RelativPanel's attached properties (such as
RelativePanel.Below, RelativePanel.Above, RelativePanel.RightOf,
etc), you can position a UI elment relative to another UI element as
well as relative to the panel (e.g.,
RelativePanel.AlignVerticalCenterWithPanel).
RelativePanel, used in conjunction with AdaptiveTriggers, can be a
powerful tool to create responsive UI that scales well across
different screen sizes. If you want to explore further on this, there
is a sample you can download and experiment with.
i'm trying to do an application for Windows 8 and i'm following a guide on channel9.msdn
I cant understand why they use XAML to create textbox, label or other controls.
There's a reason ? There's a form which is much faster: simply drag & drop controls into the UI.
So why use XAML ?
Thanks all and sorry for my english :/
XAML supports laying out the form so that if you resize the window, the controls contained in the window are always consistently positioned according to the layout.
If you just drag and drop, you will see that the designers uses margins to position the controls. When you resize the window, they kind of keep the same position and are not going to be well positioned anymore.
This layouting is the essence of WPF. Just read a tutorial about layouting in WPF.
Drag and drop creation of UIs when using XAML creates very poorly formatted XAML and since there are a significant number of things which are most easily done in XAML (data templates for instance), it's easier to simply construct your UI in XAML from the start.
I am using a custom Panel, very similar to a radial panel.
I was wondering if there was a way to rotate the items as well as position them.
I know I could use different item templates, but that would require assigning the templates during coding. I'm looking for a runtime solution.
Any ideas?
What I did was create an item template that rotates the item based on a data bound property in the CLR object.
In order to rotate in a windows store app, I used a modified LayoutTransformer
I have the following question:
The current project I'm working on is full of inherited controls, allowing us to tweak the behavior a bit in comparison to the default behavior. Now i created a sort of notification control (composed of an image an tooltip control) which I want to add to most of our control collection. This would allow usage of thise notification anywhere we need.
I tried dragging my own control to the design view of the inherited control and I pass on the properties that should be set on my own composed control.
Rendering however seems to be a problem. Since the original control is an inherited control, the size of that control can vary. My notification should be appearing behind the control:
[control][notification]
control being the inherited control, notification being my own control.
Is this possible on the inherited control? The only other option I see is making 2 versions of the control, one clean inherited and a composed one with both (in which case I would need to relay all databindings, which I don't want).