I've been tasked at work with creating a UserControl containing a ListView and ComboBox's for sorting the ListView data. Sorting with the Combobox's s the easy part; the part with which I'm having difficulty is implementing a method of scrolling. In the end, the control should have an Excel-like feel to it. However, sometimes the ListView is too tall or wide for where it is placed. Therefore, there two be two scrollbars somewhere on the control. One vertically moves of the ListView only, and the other moves both the ListView and ComboBox filters horizontally.
Please note in the image above that the ComboBox's do adjust themselves according to column width, but the code for that is not enabled at the moment.
What I've tried: In the control, the filter boxes are in their own panel, and the ListView has had its own panel at times. I've tried using various combinations of the HScroll/VScroll and HorizontalScroll/VerticalScroll properties and the native function ShowScrollBar() for all the controls, but nothing has worked. The only way I've gotten scrollbars to appear is by settings AutoScroll (Scrollable for the ListView) to true. Of course, the scroll bars come in pairs and work only on the same control. I also attempted to programmatically move the scroll bars, but I haven't been able to accomplish that, either.
I've got to be doing something wrong, but I'm not sure what it is. Any help is appreciated!
I think I'd go for a different solution.
If you put the ComboBoxes in a AutoSrcoll panel with the same Anchors as the ListView you would give your users the freedom to scroll the two independently.
Yes, a ScrollBar would appear and take space but I would still happily sell that as a feature, not a bug ;-)
As for handling the Scroll event of a ListView: It is hidden and you'll have to subclass it to get access to it. See here
Related
I need to create an app for TV guide. Requirement is that UI must be a copy of one you can see here: raspored.bnet.hr. As you can see, there's a lot of data. So, basically it would be a large scrollable table. Since there is no such UI control as table on Windows Phone, I found out that the best approach would be to create one vertical listbox with horizontal listboxes as its items. This is all ok and I'm able to create it. But, to make it behave like a table I also need to make these horizontal listboxes scroll in sync, not to scroll one row at a time. Then I disabled horizontal scroll on horizontal listboxes, and enabled it on the parent (vertical) listbox and while it gave the result I wanted to achieve one big problem came up - UI virtualization. I know ListBox has UI virtualization enabled by default and I can see it while scrolling on vertical listbox, but when I disable horizontal scroll on horizontal listboxes, performance is really bad, and sometimes there's an OutOfMemoryException. I understand why this happens because when I disabled horizontal scroll, those listboxes didn't know which items are on screen anymore, so the loaded all of them into memory.
What I also tried is to leave scroll on every listbox so they have UI virtualization, and then place ScrollViewer above them. Then I tried to listen on Manipulation events on scrollviewer and progamatically scroll all of the listboxes as needed. This didn't work good, first of all ManipulationDelta event doesn't appear to fire frequently enough to make scrolling smooth, and I think there could be a performance problem with calling ScrollToHorizontalOffset on ~180 listboxes.
I also tried the LongListSelector from WP8 as I read that it has much better UI virtualization and should be used instead of ListBox. The problem with this is that I couldn't make it scroll horizontally. Is it possible at all? I tried to wrap it into ScrollViewer which can scroll horizontally and it's working, but only if I set fixed width on LLS.
I also tried Telerik's RadDataBoundListBox and the problem was similar, I can't get both horizontal and vertical scrolls on the same listbox. So I could only get that each list scrolls on its own.
Can someone tell me if they had similar situation and what would be the best approach to solve this? I believe I'm not the only one that has this requirement to implement large scrollable table.
Thanks
UPDATE:
I'll just inform you that I didn't find a proper way to implement this, instead I've done it in HTML with WebBrowser control. Seems like IE already has UI virtualization implemented so it can work with large pages very well.
May be in your listbox there are images? and Out of memory Execption will occur you can do 2 things:
Don't load data in one time use BackgroundWorker
Have one local image in the App of the image you are downloading and set it as default image & when you scroll to some 50 values in forward clean the image Url to local and when it comes back give again the image url you want to show .
Because i have used it to scroll around 20k values.
I am developing an application that will use touch screens to navigate for use in a warehouse environment.
There is a need to present a list to the users and because this list could be quite long, the user will at some point need to scroll down the list.
As you all know the system scroll bars for panels and textboxes etc is quite small and I would like to know if I can either resize the controls that make up the scroll bar (the little arrows at the top and bottom, and the place holder bar in the scroll bar itself), or if I can create a couple of buttons that can scroll up and down my control for me?
Thanks,
Karl
Answer pulled from this post.
Check this out:
Winforms - Adjust width of vertical scrollbar on CheckedListBox
Worth mentioning too:
.NET Compact framework - make scrollbars wider
More of the same, but this time with a better solution through the use of the scrollbar control:
Change the width of a scrollbar
Another one in which the guy teaches how to create your own scrollbar control (interesting):
Set the Scrollbar width of a DataGridView
The last one (worth trying):
Is there a way to get the scrollbar height and width for a ListView control
You can add your own scroll buttons and programatically scroll like so:
myPanel.VerticalScroll.Value++;
I am making a WP7 app which has a Listbox of UserControls. Each UserControl has an ItemsControl and Button(for getting more results). On click of the button the ItemsControl items will be increased by 5 or 10.
Now on clicking on the GetMore button of any of the usercontrols except the first or last, there will be an increase in Scrollable height(Total height of the listbox) of the ListBox but the VerticalOffset(position of scrollbar from top) of the ListBox remains same. Now the problem I am facing is that the Vertical Offset is not absolute but relative to Scrollable Height. So the content being viewed till then will be changed basing on the new value of ScollableHeight.
I want to know the relation between them, so that I can do some math and set the VerticalOffset value.
I have added some dependency properties on VerticalOffset and ScrollableHeight through which I can get the events when any of them is changed. Trying to use ScrollIntoView for readjusting the Vertical Offset
Any suggestions or corrections are highly appreciated.
I am not able to find the calculation. But what can be done is listbox can be replaced by a scrollviewer which has itemsControl inside it. But the disadvantage of this is virtualisation is disabled, so will need to check on this.
But, overall this is going to give a bad experience on using such a UserControl in Listbox. So using templated list box given in WP7 toolkit is an option but it is gonna hang a bit since ListBox is not optimized for multi templated virtualization. So I started showing writing listbox item template in such a way it contains all the possible layouts which will enabled from a condition.
there is a search View ( app is a MVP - PRISM WPF ) which had some issue with scrolling. it took hell of a long time to scroll when you click the scroll bar buttons. Click and dragging the scroll bar was even worse!!
considering i like anomalies, i picked it and started looking into what was going wrong. I suspected many things, but evidently the issue with the datagrid scroll was due to "ScrollViewer.CanContentScroll=True" i removed it and the scrolling was a pleasant experience compared with earlier.
Now i was wondering why my developers had put that property as true, with in couple of mins i found Doing a Page down was scrolling more than a page with out the CanContentScroll property marked true!
Now i need the scrolling to be faster AND i also need page down and page up to scroll as expected! Can some one tell me What I am missing here?? thanks!
I had similar issues with my datagrid : slow scrolling, and also randomly size changing scrollbar.
I did the following:
simplify the templates of the cells (no more nested borders and multiple colors, ToggleButtons instead of CheckBoxes)
in code use frozen colors.
this helped speed things up but did not solve the issue.
Then i set the row / cells templates height and also the RowHeight property, and then it was ok : i had both smooth scrolling and normal scrollbar. So i guess that the DataGrid was unable to compute the size of what remained to be displayed that made both the scroll slow and the scrollbar having changing size.
(Yet the rows / cells were all having same actual height in their templates since they were defined with same controls but Height property was not set...)
Hope that can help.
I have a WPF ListView which currently scrolls everytime I click on an item which is only partially visible. How can I keep the control from scrolling that item into view (instead simply selecting the partially visible one)? This behavior is very annoying when doing a drag from this control.
Thanks.
Added: I am looking for a solution to keep the control itself from scrolling when contents are clicked that the control believes are not fully visible. Often this is by a few pixels and the scroll is not necessary.
The items scroll into view because the default behavior on list item click is to call BringIntoView(). You can add an event handler for the RequestBringIntoView event and catch it before it bubbles up from the ListViewItems to the ScrollViewer. In your handler, check the bounds of the sender against the visible region and if you decide that you don't need to scroll, set the event's Handled flag to true.
Since I'm currently on the road, I cannot try this, but have you tried playing around with CanContentScroll, and/or wrapping the scrollable content into a Panel, as suggested by the ScrollViewer Overview on MSDN?
In the worst case, you might want to replace the ListView's ItemsPanel by a hacked ScrollViewer with a "fuzz" factor, e.g. by capturing the RequestBringIntoView event.
have you tried this approach?
just as an addon, I don't know how much you know about the subject, but here is a good place to read more about it.
added:
I just found that you can prevent the mouse wheel of scrolling as well.