I need to get the actual height of the displayed content inside an opened pop up control:
Problem:
I want to show a lot of data in a grid inside a pop up. If this content became higher than the browser height, this content is cropped at the end of the window.
I there any way to get the height of this content (i know that pop up isn't in the visual tree)?
Try calling UpdateLayout() once all controls have been added to your popup.
You will then be able to get the ActualHeight of the popup.
This has a bit of a performance overhead so trying calling it as little as possible.
Related
Within a WP7 app I am generating a Scrollviewer within the code. This Scrollviewer has a StackPanel as its content and within the Stackpanel I have a grid.
I have not assigned any specific heights to these controls.
As far as the look and the behaviour I am after, all is fine.
I now want to position the scrollviewer to a certain point - after I have generated it and its children.
It seems that the ScrollViewer.ScrollToVerticalOffset method is what I should be using.
But I cannot ascertain the height of the Scrollviewer... both Height and ActualHeight are returning 0. I want to use this height to determine which point I should be scrolling to.
And even when I hardcode a ScrollToVerticalOffet value then it still doesn't reposition itself.
Is there a way that I can get this to position as I want, and how can I determine the height values?
thanks
Got it working ok when I checked for values in the Page loaded event... and the ScrolltoOffset seemed to work fine there too.
I want to convert a xaml canvas to a png image using c#. I used RenderTargetBitmap as described in the second post here. It works quite well if the xaml that's meant to be converted is displayed in a window or a page and you can actually see it on screen. But if the window is closed or hidden or the canvas isn't a child of a window / page / frame, a blank image will be generated. Does anyone know why this happens or how to make it work?
I can't be sure but it may be that WPF is saving time by not rendering anything that isn't currently on screen, therefore when you grab the bitmap from the render target for that object, it hasn't been rendered and so it is blank.
I would suggest putting it on screen for the duration of your capture and then remove it. If the object is small it may even appear and disappear in no more than a flicker.
I've got a Silverlight user control that contains a datagrid. The datagrid is bound to an ObservableCollection. The user control is displayed in a popup window that I show in response to some event in another control
There are about 80 objects in the collection, and I've set a fixed height of 400 on the datagrid, so only about 20 items can be shown at one time, and the vertical scrollbar should be shown, with a thumb size occupying about 1/4th of the control height.
However, what's actually happening is that the scrollbar occupies almost the whole control height; maybe 95% of it. The datagrid displays the first 20 items. When I click on the scrollbar down arrow, the scrollbar moves down a little to occupy the bottom 95% of the scroll area, and the datagrid displays the last 20 items.
It gets weirder. If I move over the items in the grid and scroll down using the mouse wheel, then the items scroll correctly and I can view the whole list, although the scrollbar remains the same size.
And then, if I close the popup and reopen it, the scrollbar now appears with the correct height and it works correctly.
Finally, if I just show the control directly on the page, and not in a popup, it works fine.
What's going on here?! Has anyone else run into this problem? Help!
Update: The problem seems to be the way that I'm showing the popup. For various reasons, I had to implement the popup display in a somewhat tricky way, and it's this that's causing the trouble.
I recoded this, removing some crufty stuff, and the problem went away; see my update. This isn't really a solution as such, but I wanted to close out the question for the record.
I would like to animate a transition when moving content between two panels. I am getting a bit map image of a detail record and docking it as a thumbnail in the panel below. The docking area is in a footer grid and the content detail is in another grid that sits above the dock area (the dock and the main content area live in separate rows of the root layout control - another grid).
I have tried implementing this with a ScaleTransform and a TranslateTransform, simultaneously shrinking the image and moving it towards the footer control. When it moves into the footer control, it gets clipped even though the image Canvas.ZIndex property is set to a very high number. Eventually the thumnbail will need to be a child of a StackPanel that sits inside the footer grid.
Thanks for your consideration and help.
I had a similar problem (clipping) with a WPF animation I had. The problem was that the owner of the animation needed to be a parent of both containers for the animation to work (in my case I made it the actual window holding the containers).
Without any code, I can't see if that is your problem, but I thought I would throw it out there.
You can see my code where I animate moving from one container to another here:
http://wiassistant.codeplex.com/sourcecontrol/changeset/view/36638?projectName=WIAssistant#924851
(See the AnimatePaneBox method at the bottom of the file.) This may or may not be useful to you.
I've done something similar by creating a Canvas that sits over the top of both containers, using a WritableBitmap (if necessary) to create a rendering of the object that you're moving and attach it to that Canvas, animate the bitmap (translate, scale, opacity, whatever), and then pop the new object in under it at the end of the animation. It can be brittle if your controls need to be able to move or resize, but in most of my circumstances it's been a reliable hack.
I currently have a Silverlight canvas that exceeds the viewable area of the screen (I'm letting the users drag the viewable areas around to navigate). I'm trying to display a modal popup that always shows up in the middle of the viewable area, and I can't seem to find any property that tells me what currently is on the screen. Basically if the user has panned down to the bottom and clicks something that causes a modal popup to appear it is stuck at the far top of the screen.
Any ideas anyone?
Thanks
~Steve
I don't think this is possible since the visibility isn't being surfaced. Perhaps with some fun JavaScript to figure out where the panning is?
Quite true. I wound up creating a holding canvas, making that full screen, and putting everything else as a child canvas within that. The modal popup now comes up in the holding canvas.
Gabriel Guimarães one works good.
App.Current.Host.Content.ActualHeight(and ActualWidth) does bring the browser size inside. Good for calculating position. And of course you can use LayoutUpdated on your main control to double check the sizes and resize stuff if need be.