I am new on xaml, vb.net and coding. I'm trying to make an app with ListView.
I know how to use ListView but I want another kind of ListView: a ListView with one item which allow us to add an item.
I don't know how do that. Maybe UserControl?
I attached a sketch for better understanding.
There are a couple ways to go about this. Basically, it all comes down to using some Event to trigger the creation of a new item. One option is to make the last item a Button and handle the Click event. In the event handler, you would have code to insert an item one place before the last item in the list.
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I have a ListBox in a Silverlight Application. I'm trying to make an editable listbox, so I use an ItemTemplate to have the controls i need in each item, like a textBox and buttons, and its working fine.
I'd like to have a line at the end of the Listbox with a button to add new items. Since this item won't be related to any of my domain classes, I'm using a plain object as a 'Filler', and then I have code that identify this item to show the button correctly.
myListBox.Items.add(new object());
The problem is that I want this "new Record" item to be kept always at the end of listbox, so when I need to insert a new domain record, i use this code:
myListBox.Items.Insert(myListBox.Items.Count - 1, domainItem);
When I debug the myListBox.Items collections, it is in the right order, with the "add new" button at the end, but the listbox is displaying this button at the beggining. Why are my items beeing displayed in a different order than the Items collection?
Unless there is a specific reason, instead of trying to put the button into the listbox collection itself you would be best to create a new control with the button outside and below the listbox. You can always style the button to look as though it's within the listbox if required.
Is there a reason why you are not using a datagrid because it would remove all your ordering problems and it would allow you to edit the entries.
The datagrid is bound to an ObservableCollection which automatically connects your editable fields to the GUI.
Cheers,
Is there any way to tell when the containers are finished being made for a ListView?
A detailed explanation of what I've done so far
I have a ListView control that has a DataTemplate in one of its columns that contains a CheckBox Control.. I've figured out how to access the CheckBox dynamically using the object that the ListView is bound to.
ListViewItem lItem = (ListViewItem)ListView.ItemContainerGenerator.ContainerFromItem(trackToHandle);
CheckBox checkBoxToHandle = FindChild<CheckBox>(lItem, "CheckBox");
The problem is that the CheckBoxes "reset" (become unchecked) whenever I scroll too far or whenever I sort the columns.
I figured out this was because the VirtualizingStackPanel was only spitting out containers for those ListViewItems that were visible (or almost visible)..
And because the CheckBox is inside a DataTemplate that is defined in the XAML it gets thrown away everytime it goes out of view or when the list is sorted.
I got around this by creating a separate list of CheckBoxes and using the actual CheckBoxes "click" event to change the state of the corresponding CheckBox in my list.. then made a little method to go change the state of all the visible CheckBoxes whenever the user scrolls... as a result it appears like it should have in the first place.
Except when I sort the columns.
I tried making it re-do the CheckBoxes (like before) right after it'd sorted a column but it didn't work.
My best guess is that it doesn't immediately make the containers after I sort..
Is there any way to tell when the containers are finished being made for a ListView?
If you bind your checkboxes IsChecked property to a boolean property on your data context, then you will not have this issue.
The whole purpose of the VirtualizingStackPanel is reduce memory usage by not creating ListItem's unless needed.
In effect, you need to move the data side of the checkbox away from the control.
Now I'm about to learn RoutedEvents. I understand bubbling and tunneling and all. But I have a little problem I'm not sure how to handle.
I've got a ItemsControl in my own defined UserControl ( inherits TabItem ). This itemsControl could be a ListBox or some selector not decided yet ( depends what is best with this solution ).
Now when one item there is selected ( Not sure yet what the best selection method would be, perhaps doubleclick ) I need to capture the event in the TabControl that holds my UserControl. Thankfully as my userControl is put into the XAML visualtree the bubbling event flows up and events can reach the TabControl. However I still have a few problems with implementing this.
1) Let's say I set it as MouseDoubleClick I don't wan't other DoubleClicks ( like in other tabs or outside the ItemsControlItems ). I guess you can always do a check where the events coming from to ensure it's the right one but I don't feel it's the right way and it could be asking for trouble.
2) If I set the event to SelectionChanged and the ItemsControl to ListBox I would have to ensure the ListBox itself doesn't handle it so it can reach the tabControl. How would I do that?
3) Same as 2) but the TabControl is a selector itself so it would raise it's own selectionchange events wouldn't it. how would that work. Would the handler grab both from the listbox and the TabControl?
4) Not sure what ItemsControl I should use. If i'm only using it to doubleclick the item and then handle the event wouldn't ListBox be too much. It has many effects that would be undisireable like selection and such. Is it better to define your own ItemsControl or maybe use ListBox and overwrite some of it's properties like selection ( how would one do that? )?
5) The source of the event would be the ItemsContainer but I wan't the item itself. There is a easy way to get access to it isn't there?
6) Let's say I put a button and in the DataTemplate I wan't to attach the ID of the object through the button and capture it where the button click is handled to identify what item it was. Is there a property do do that or would I have to define it myself?
7) Would the best course of action here maybe to create my own event?
Your take on this issue and comments on what process is best to take here is appriciated.
EDIT: Decided to add little bit more info as asked.
What I'm aiming for; when I start the program I have a TabControl with 1 tab in it. This tab is different from the rest of the tabs will be because it holds a list of objects (CompanyModel). This list is the ItemsControl I mention. When you press one company from this list a new tab is added with info about that company.
My solution was to create a TabItem collection as a source for the TabControl. Then I would define my 2 types of TabItems in a seperate XAML source file (not sure what to call it, basicly add new usercontrol). One is the initial where thhe list appears, the other one takes in a CompanyModel as a constructor parameter and shows info about that.
This works while I don't like the idea of defining the company list tabitem seperatly I can't define it under the tabcontrol because I can only have defined items or sourced, not both.
I've tried this idea by putting a button on the List DataTemplate that bubbles the Id of the company selected up to the TabControl, handling it there and adding a new TabItem with the CompanyModel. That was just a solution to try it and has problems like if I add anpther button to the CompanyTabs I would grab them aswell in the TabControl.
So my problem could be solved by finding a good way to bubble a event from the original listTab or If I would be able to define the tab in the same place as the TabControl.
I know that one other solution would to have the list seperate from the TabControl but others would like to see how this comes out and I would like to learn how I would do this.
please have a look in this blog, may be it will helps u.
http://blogs.u2u.be/diederik/post/2009/09/09/In-WPF-SelectionChanged-does-not-mean-that-the-selection-changed.aspx
I've got a list of things that I want the user to easily edit the order of. Right now I'm binding them to a ListBox with a custom ItemTemplate. Within that template I have an UP & DOWN button. My goal was to move the item up/down based on the button clicked.
However I'm having trouble associating the button's click event with the actual item in the list. I've seen some folks setup a drag/drop for ordering items but that that would be too complex for this app (it's target user base =1, just me).
I assume this is possible with a ListBox. Maybe someone has a beter idea on how to implement this? It's not a huge set of data... less than 25 items.
The DataContext of the button (of the entire template, thus inherited by the button) is the item itself. Simply cast it to your desired type.
Actually I'm using an items control and animating the children of it. The problem is when adding the items dynamically through Add() method the first item is not getting animated and just comes to display as usual.
I've planned to hide the dynamically added child and later make it visible when i want to use it with animation and that way i can bring it into view with animation.
To hide the child when it gets added dynamically i need some kinda of notification or event fired for Add() method!. I tried using InotifyCollectionChanged but that didn't work.
Your thoughts please..
Your alternative suggestions are also appreciated..
Thanks in advance...
First option is to check this question: Animate WPF Datatemplate when item added to Listbox?.
Another option would be to create your own ItemsControl and override OnItemsChanged() method. But it's not as easy as the first option.
Hope this helps.
I'd probably bind the listbox to a collection in a ViewModel, and add directly to that rather than adding to the ListBox.
Hi guys i found the solution for my problem, this may help those who are struck with such an issue.
This can be achieved by using a grid as your itemsHost and dynamically adding the children of itemscontrol to the grid and animating it. since the grid get its children only at the runtime we have more control over it and decide when it should be rendered on the screen.