I created a user control in Silverlight, so now I can siply reuse it multiple times anywhere I want. This control also uses a popup. When the popup is opened, I programatically set its position so it looks like anchored to the control. But when this popup is already visible and user changes size of Internet Explorer window, the contens of page are moved and the popup is not moved. [Obviously.] So it doesn't look like anchored to the control anymore. How to fix it? Which event to handle?
I expect there is some event which is fired when user changes size of the window. Or even better an event which can inform me when the owning control is repositioned, so I know the new position of the control (which I need to know in order to compute the coordinates for the popup). Since I want it to work as a user control, I would prefer a local event on the control itself (i.e. without messing with any global page/window stuff). Please help me to find the right event.
Update: It seems to me now that LITERALLY I need to know when the owning control is moved. Because there can also be other reasons why it's moved (other than abovementioned change of the window's size).
I think you are looking for the SizeChanged event. You can subscribe to that to know when to resize your popup.
If your control is moved because of another control, this may not help though. As it may not resize, just be arranged in a new location.
If that's a problem, you can use the LayoutUpdated to determine if anything changed inside an element. For this you'd need to attach a handler to the RootVisual or something above your element.
Related
In Winforms if the MDI child window is maximized it doesn't receive ResizeBegin (or ResizeEnd) events. It does receive Resize events - why the distinction? If the child isn't maximized it does get ResizeBegin/End events. Is there a nice way around this? There are plenty of ugly ways: calling directly from the MDI container ResizeBegin event to the child for example.
The ResizeBegin/End events are generated when the user starts and stops resizing a window. Implemented by a modal loop inside Windows itself, it keeps the window edge following the mouse cursor when the user moves it. ResizeBegin when he clicks a window edge, ResizeEnd when he releases the mouse button.
Clearly no user is involved when you change the Size or ClientSize property of an MDI child window in your code. So no Begin or End, just the Resize event. And just one Resize event trigger, there's no constant train of them like there will be when the user uses the mouse to resize. Which otherwise explains why Begin/End is important, if you do a lot of work in your Resize event handler then you'll bog down the UI pretty heavily. Common with automatic layout, the visible artifacts are not pretty.
If you really have to then you can simply generate the event yourself. Call OnResizeBegin() before, OnResizeEnd() after you change the window's Client/Size property value. That code needs to live inside the window you resize to get the correct event triggered. Pretty unlikely you should be doing this btw. Do beware that MDI automatically resizes an maximized MDI child window, it of course cannot be maximized anymore when you activate another one. You can't wrap that with OnResizeBegin/End() calls.
I have some simple code for popping up a "dialog"-like thing over part of my application window. The idea is, the user must dismiss the dialog before continuing to work with that part of the page.
This works by hovering a large semi-transparent rectangle over the part of the page that is supposed to be disabled - which does a nice enough job of blocking clicks to the region. You see this sort of thing a lot in WPF and Web apps, I think.
The problem I have is, the user can still reach all those juicy blocked controls by tabbing to them using the keyboard. "No problem", I hear you say, "just set the IsEnabled on the panel to false, thereby blocking keyboard access".
Unfortunately, disabling the controls:
Doesn't look very nice
Tends to have unintended consequences with custom styles and bindings further down the tree
So, is there a better way to disable a part of the page, without setting the "IsEnabled" property, such that it doesn't change the visual appearance of any of the controls?
Thanks,
Mark
Can you put your "dialog" XAML in a popup window? Then, call ShowDialog() on the window to make it a modal window? If you don't want your popup to look like a standard window, you could always syle it to remove borders, etc.
I solved this by subscribing to the PreviewGotKeyboardFocus event, from the parent element in the tree, and then handling the event such that focus never gets passed to the children.
Also, I had to explicitly remove focus from the "disabled" controls as well, of course.
I would like to have a form which has a few controls as transparent overlays over a bitmap. This bitmap is subject to transform matrix (zoom & scroll). I'm trying to achieve a look similar to GoogleMaps where the controls do not move when the background image is panned/zoomed.
I've tried to mimic this in my OnPaint. However, when the window is scrolled only the newly exposed area gets invalidated so my control doesn’t repaint.
I've tried to calculate where the old control was, invalidate that area, and also invalidate the area where it's supposed to have been. When I do this it flickers and you can still see the image as its scrolled.
I tried to put a ButtonControl on my display window. However, it always scrolls with its parent control. I tried to capture the scroll events and then adjust the position of the ButtonControl. This also has a delay update effect so it looks not so good.
Any ideas would be greatly appreciated.
It sounds to me like you need to Invalidate() your control wich handles the OnPaint event.
Unfortunately, you get the flicker because the Auto-scrolling mechanism sets its position, and then you restore it. The result is two messages being sent to the button.
Place your bitmap and scroll logic in a separate control that fill the entire form. That means both your bitmap control and the button are child controls of the form.
Alternatively, draw the button yourself. You will then of course need to do some work on getting it to respond to mouse clicks etc. The ControlPaint class has methods that help you mimic the appearance of Windows controls.
If I create a ComboBox from scratch, when the window is resized, the content is correctly displayed above/below, etc.
Why this doesn't happen when you create your own Combo-derived class? What am I missing?
Controls aren't magical. They need to be told that things happen (call a method on them) or look for them to happen (register for an event).
Find your Application.RootVisual and register for a SizeChanged event. Then resize your control. If it is in browser you may need to create a javascript bridge (hopefully not) that tells your SL object when the browser resizes.
From what I understand, the popup exists within it's own visual tree. However, I've noticed a few properties, Clip and ClipToBounds. What I am wanting to do is Visually clip a popup at the right and bottom edges of a window regardless of the fact that the popup is independent of the bounds of the window. I'm not using XAML, but if somebody knows how to do it in XAML, then that's fine. I can get to the main window using System.Windows.Application.Current.MainWindow. Is it possible from this to get a value that I can use to clip the popup? I'm assuming that if there is a value that I can use, then I would be able to bind the clipping of the popup to that value. This is really not necessary since after the popup initially opens, if the window gets moved or resized, the popup closes. So I would really only need to clip the popup when it opens. The reason I would like to do this is because although I am using a popup, I don't want it to appear as a popup that exists outside of the window. FYI this is for a popup calendar for a custom datebox. Any ideas, as well as clarification of misconceptions that I may have, would be greatly appreciated.
Furthermore, the popup can be launched from a user control that is not directly on the Main Window. So in that case it would be easier to use a popup. As apposed to a UC inside the XAML
I know this is a year old post, but in case any others come here looking for answers... If you don't need the popup to be outside of your window, why use a popup at all? It'd be far easier to simply use a control in a canvas (for instance) and control it via its Visibility property. Then you'd automagically get your clipping.