In my application user can scroll up/down MainWindow.
Problem is, that when a user scrolls down MainWindow and some controls in it are not entirely visible ( for example user scrolled down and only the bottom of the control is visible) these controls are not refreshing/updating its values (provided via binding). I suspect that WPF is detecting, that control is not visible in some way and does not bother to update UI of it. So how can I force these controls to update their UI?
For example, in picture below there is some chart in the MainWindow.But the window is small and scrolled down so the chart is not entirely visible. It does not update, it is still. When I maximize the window chart starts updating. I want it to update always, no matter how small part of it is visible:
This is a virtualization problem, and you need to turn off virtualization for your chart (look at the chart vendor's documentation).
In the standard WPF controls there are many ways to do this.
Related
So I am making a dark mode option for my application and I want the scrollbar back color to also change color so that it doesn't look out of place. I have tried to search for a solution but so far I have only found code for a scrollbar as in the control. but I need to change the scrollbar of a panel. Does someone happen to know how to do this? Thanks a lot in advance.
I faced the same challenge when I started to work on custom controls that should support the Dark Mode. The problem with Panel control as well as other controls is that their ScrollBars are managed internally by those controls and there is no way to customize them.
My Idea was to create a custom ScrollBar control that supports custom colors and themes, see my answer https://stackoverflow.com/a/73613059/5514131
And in our custom Panel control, we create the custom ScrollBars internally and use the various Panel properties and events to link the custom ScrollBars to our Panel.
With the help of the Panel VerticalScroll and HorizontalScroll properties, we can know whether the default Panel scrollbars are visible or not and their properties to copy to our custom ScrollBars.
With the help of LocationChanged, SizeChanged, and other Panel events and properties we should bind the custom ScrollBars to our Panel and place them on top of the default ones to completely cover them.
I used the OnMouseWheel and OnScroll to update our custom ScrollBars when the Panel is scrolled using the code or mouse wheel.
We should dispose the custom ScrollBars when the Panel is disposed, or its handle is destroyed.
I know this isn't the best approach, but it should work to prevent the default ugly scrollbars from ruining your beautiful Dark Mode.
This workaround can be applied to other controls, I actually used it with TabControls, however, it will be more complex to implement.
Windows Forms Panel control with custom ScrollBars based on the Flat ScrollBar control https://gist.github.com/ahmedosama007/39f8b76e65300e5969110b753fe0a654
I have the following application:
I am developing a Windows Store app in which I need to show a big grid filled with buttons. The content of the buttons are some numbers and when I click any of them, I open a Popup with editor, where I edit those numbers. For that purpose I use a GridView, I put an ItemsWrapGrid as ItemsPanel. This makes the grid look exactly as I need it to look. I put the GridView inside a ScrollViewer, because I need to scroll the grid in both directions, since it has a lot of elements. Also I need to have the pinch-to-zoom effect that the ScrollViewer gives out of the box. I need to change the ItemsSource for that GridView when the user chooses different source in a ListView next to the GridView.
The problem:
Putting the GridView inside the ScrollViewer breaks the Virtualization inside and this has a major impact on my performance. When I switch the ItemsSource of the GridView, it takes more than 3-4 seconds for the rendering and during that time, the UI is frozen.
My question:
How can I keep the awesome stuff that the ScrollViewer gives me and also keep the virtualization? Because when I remove the ScrollViewer, changing between the ItemsSources happens almost instantly.
Any idea?
You'll be best off implementing virtualization yourself since you're trying to use the GridView far from the use cases it was designed for.
Put a Canvas in a ScrollViewer that does both pan and zoom and handle view change events on the ScrollViewer by laying out item containers inside and around the viewport. Avoid unnecessary changes too, so keep containers in place if they are to stay realized between view change events and recycle containers that are leaving the viewport neighborhood.
I needed a modal dialog for my app but it appeared there is nothing like that in XAML Metro app. Someone suggested a popup.
I tried and it appeared that underlying UI still responsive.. so a Popup is not modal.
I thought OK may be its purpose is to be a popup in the center of the screen regardless the other layout and it appeared - not. Popup is bound to a layout as everything else. if it is in a grid it will be placed in row 0 and column 0 not in the center..
So may be I missing something. please help to understand. I cant find any use for it different from what can be achieved by using Grid.
what is the purpose of Popup? how it different from any other content controls?
Differences:
You don't have to put it as a child of another control. Though in such scenarios you might get problems traversing the visual tree and focusing on a TextBox won't shift its contents so the virtual keyboard might cover its contents or its adorner contents might lose alignment to adorned controls not on the Popup.
Its content tree is rendered on top of any other content and (I believe) doesn't get clipped by parent control's Clip regions.
You usually need to set its Width and Height manually when first showing or when parent layout (or size) changes, especially in one of the most common scenarios when you set its Width and Height to the Width and Height of the parent (or the window).
That said - modal dialogs are bad UI and should be avoided. You can simply navigate to another page if you would otherwise want to display a dialog or use other approaches. There's (almost) nothing more annoying than displaying a modal dialog over UI that looks otherwise enabled but doesn't respond to input.
I needed a modal dialog for my app but it appeared there is nothing like that in XAML Metro app. Someone suggested a popup.
Since Windows 8.1, there is actually something similar to a modal dialog that you may want to look into:
It's called Flyouts.
Apparently a modal popup with custom content is missing in Windows 8.1. One possible workaround:
use a Popup control (per se not modal)
make the background semi-transparent
stretch it across the entire screen
place the actual popup content inside that container and leave some space around it
Now, the parent page is visible but dimmed, and it cannot be accessed as the Popup is covering it.
I've tried looking many places for an answer to an issue I'm having and so far I've found nothing.
What I currently have is a c# windows form with user controls inside it. Some user controls have other controls inside them. What happens when I change the text in a textbox, is its parent windows will no longer resize like they should when changing the window size. i.e. A horizontal scrollbar will appear even though horizontal scrollbars are disabled in that specific window. Its almost as if changing the text changes the parent window's styling.
In case this is too vague, I have a textbox inside a panel with a docking property set to fill. The panel has a padding of 10 in order to allow the textbox to have some white space for aesthetic purposes. This control resides within a parent control (we'll call it parent 1), which in turn resides within another control as well (we'll call it parent 2). So when I change the textbox's text (at all, even adding a space), will then make parent 2 have a horizontal scrollbar flicker and sometimes even remain when resizing the form window manually.
You should make sure that not only the TextBox in the UserControl is docked to fill but also that the user control itself and its parent (and its parent) are Docked correctly or have anchor set so that they resize with the Form.
Do you execute any special code when the user enters a character? (KeyPressed event etc.). If yes you should try disabling the events temporarily to see if they cause the problem.
If you post a sample of your code it would be easier to help. Without this we can only guess, like I tried...
I found out my issue! When using autoScrollBars and double buffering, it caused the horizontal scrollbar to show when it shouldn't have (at least in my case) when resizing the window. The answer was simple, forget the autoScrollBars, and implement my own vertical scroll bar!
I was actually getting some code to post up on here for you guys to look at, but when looking at it, I decided to forget the autoscroll, and lo and behold it worked!
I'm actually curious as to why that is though. My friend heard that .net has some issues with autoScroll but I didn't think it would be to this degree.
A disclaimer first! This might be a very fundamental question, but I have started learning Winforms Application Development on my own (.net 3.5,C#), and I have this resizing question.
I am developing a small Winforms application that has a standard tab control (along with many other controls) placed in the form. (It has 5 TabPages)
The AutoScroll property for the TabPage has been set to “True”. On reading up what I got to understand is that this will enable the scrollbars to show up at run time while resizing. i.e if the height of the form is reduced it will cause the vertical scrollbar to show up within the TabPage.
While the application is running, what I noticed is that if I reduce the height of the form using the little double headed arrow, the scroll bar does not stay on top, i.e if I adjust the height from below, the bottom end of the scrollbar is no longer there. More precisely I am just looking for a way to keep both ends of the scrollbar on top within a TabPage when the form containing the Tab control is resized.
It sounds like the problem is that the tabbed control will show scrollbars and may well autosize, but you haven't told the form what to do.
You might want to look at the 'Dock' property of controls, which causes a control to fill a specific area of the form (or other parent control), no matter what it is resized to.