I have a combo box in a wpf c# application. In the xaml i am trying to do the following.
The ItemsSource comes from one variable.
SelectedItem sets a value on another variable
But i want the text displayed to come from a new variable.
How do i stop making the selected itemssource appear as the main text?
<ComboBox x:Name="ComboPlay" FontSize="14" MinHeight="20" Margin="0,2,4,4" Grid.Row="1" Grid.Column="3" MinWidth="160"
ItemsSource="{Binding ComboBoxList}"
SelectedItem="{Binding OutputChannel.Value, Converter={StaticResource ResourceKey=ValueToStringConverter}}" Grid.ColumnSpan="1"
IsEnabled="{Binding IsDriveChoiceEnabled}"
HorizontalContentAlignment="Center" VerticalContentAlignment="Center"/>
If you mean changing the display of the item currently selected (the portion of the control shown when the dropdown is closed), take a look at Can I use a different Template for the selected item in a WPF ComboBox than for the items in the dropdown part?
Honestly, a quick search dug up that one and many similar ones. Probably the simplest way, like the linked answer, is to figure out if your item is wrapped in a ComboBoxItem and display it differently then. Or you could re-template the ComboBox. Or you could derive from it (and re-template it) and provide a separate dependency property for the template of the selected item, if you expect to reuse it in different contexts. The sky's the limit.
Related
I'm trying to highlight part of text in a textblock from a listbox datatemplate which in turn is bounded to a property of a custom class by using a textbox to search the list for input text. But the problem is that only part of the items are highlighting (most of the ones visible) but when i maximize the window and try to input another character then suddenly all of them gets highlighted my guess where the problem might be is in this piece of code:
ListBoxItem listboxItemFound= (ListBoxItem)this.listBox1.ItemContainerGenerator.ContainerFromItem(TItem);
Since this method is returning a null when the items are not visible but the items are currently in the listbox. Somehow I guess the items listboxItem instances are not yet created until you scroll down or maximize to view more items.
XAML DataTemplate:
<DataTemplate>
<Grid Name="gridOfListbox" Height="25" Margin="0,2">
<DockPanel Name="dockpanelWithTxtBlock">
<TextBlock Name="textbloxk" DockPanel.Dock="Left" FontSize="15" TextAlignment="Center">
<Run Text="" /><Run Background="Yellow" Text="" /><Run Text="{Binding ProductID}" />
</TextBlock>
</DockPanel>
</Grid>
</DataTemplate>
If more code is needed just let me know.
Any help would be greatly appreciated!!
Also if there is any other better way of finding the listboxItem bounded to the custom Item just let me know. Thank you very much!
[Pic of problem] http://i.stack.imgur.com/HViag.png
One way to fix this is to set VirtualizingStackPanel.IsVirtualizing to false for your ListBox. This will cause all of the items to be created right away. The downside to this is if your ListBox has many items, your program will use more memory (since more items will be created), and could potentially run slower depending on the number of items.
A better solution to consider would be to have multiple DataTemplates for this - one without the highlight, and one with. You can set a DataTemplateSelector for your ListBox (using the ItemTemplateSelector property). The selector can choose which template to use based on if the item matches the search term or not.
The tricky part would be writing the template with the highlighted text. You could probably achieve that by having properties on the object the ListBoxItem is bound to for the text before the highlighted text, the highlighted text, and then the remaining text.
I'm new to WPF and I have this ListBox which I want to instantiate with a specific ListBoxItem, so the user knows what to do with the ListBox.
<ListBox Name="DbListBox"
Grid.Column="3"
HorizontalAlignment="Left"
Height="246"
Margin="0,99,0,0"
Grid.Row="1"
VerticalAlignment="Top"
Width="211"
SelectionMode="Single"
SelectedItem="{Binding Path=selectedDB,Mode=TwoWay}"
AllowDrop="True"
Drop="DbListBox_Drop">
<ListBoxItem Name="ListBoxItem" FontStyle="Italic">Drag .db file here or add below</ListBoxItem>
</ListBox>
Then I have some code which adds a collection of items to the ItemsSource of this ListBox, but I can't do that since the ItemsSource is not empty
DbListBox.ItemsSource = DbCollection;
My question is, how can I start up the ListBox with the item inserted first, and then when DbCollection is added to it, it simply overwrites the first ListBoxItem?
When using WPF properly, we'd normally have something like this, where a collection property would be data bound to the ListBox.ItemsSource property:
<ListBox ItemsSource="{Binding SomeCollectionProperty}" />
Once we have this XAML, we don't need to touch the ListBox again, as we can add or remove items from the data bound collection and they will magically appear (or disappear) from the ListBox:
SomeCollectionProperty.Add(new SomeDataType());
SomeCollectionProperty.Remove(someItemFromCollection);
The SomeDataType used here is up to you... it depends on what you want to display in your items. If it was just a plain string for example, then you could simply do this to add your initial item into the collection:
SomeCollectionProperty.Add("Drag .db file here or add below");
If you wanted to make that item look different to the others then you'd need to data bind a custom class that has a Text property and FontStyle property for example. You could data bind these properties in a DataTemplate to design each item to be exactly as you want it. However, that's a completely different question.
To find out more about these things, you can read the Data Binding Overview and Data Templating Overview page on MSDN.
Say I have a ComboBox which has an array of doubles as the ItemsSource. In that array are the numbers "1.0" and "2.5". If I change the SelectedValue to "3.0" the ComboBox goes blank. How do I get the ComboBox to display "3.0" without having to add it to the list of possible values that would appear in the drop-down box?
I guess what I'm really asking is do I need some sort of customised combobox to display an item that is not in the drop down list?
The simplest (but not best) way to achieve your requirements (gathered from the comments because you didn't explain them properly in your question) is to add a TextBlock in front of your ComboBox:
<Grid>
<ComboBox ItemsSource="{Binding Items}" ... />
<TextBlock Text="{Binding Output} Visibility="{Binding IsOutputVisible, Converter=
{StaticResource BooleanToVisbilityConverter}}" />
</Grid>
You could then add a bool IsOutputVisible property to make it visible or hide it whenever you need to... you'd need to use a BooleanToVisbilityConverter to make this work.
I have this WinRT XAML:
<ComboBox x:Name="comboxGroupName" Grid.Row="1" Grid.Column="1" Grid.ColumnSpan="3" Margin="4" Width="200" Height="36" HorizontalAlignment="Left" ></ComboBox>
When I click in it to enter a new value, though, it seems to convert itself into a readonly textbox (it loses its down arrow and disallows any typing into it). What do I need to do to allow adding values into the comboBox? Or do I need to use a separate TextBox to do that (I reckon so, but I'd like to avoid that if reasonably possible)?
It looks like your only option will be to use a seperate TextBox. There is an IsEditable property, but it states:
Gets a value that indicates whether the user can edit text in the text box portion of the ComboBox. This property always returns false.
and the ComboBox Page states:
You populate the ComboBox by adding objects directly to the Items collection or by binding the ItemsSource property to a data source. Items added to the ComboBox are wrapped in ComboBoxItem containers.
Im cleaning up this question and going to put in an example that makes sense to me..hopefully for you too...
so lets say i have an Items control. This control is bound to an observable collection of NBA Basketball teams (Lakers, Heat, Knicks...ect). In this observable collection of NBATeams I have a property of FavoritePlayer. I have a datatemplate that lays out how this is going to look inside the Items Control. I have a textbox which displays the team name. (this could be/should be read only..its not now) but it displays the team name.. LA Lakers. the second item in my items control is a combobox. this combo box will ultimately display my favorite player on each team.
The itemssource on the combobox is from a lookup value i have. It displays all the people on the team and the displaymemberpath on this combobox is "DisplayText"...I need my selected item on this combobox to be shown. so if my favorite player is Kobe Bryant the combo box should display this.
<telerik:RadComboBox Grid.Row="0" Grid.Column="9" Width="150" EmptyText="--Select Player--"
ItemsSource="{Binding PlayerList}"
SelectedItem="{Binding FavoritePlayer, Mode=TwoWay}"
DisplayMemberPath="DisplayText" HorizontalAlignment="Left"></telerik:RadComboBox>
I am used to just having textblocks in a listbox and then when an item is selected from within that listbox i use that selected item to bind my comboboxes that live outside of my listbox. Now i actually have the combobox in the listbox(ItemsControl now). So Im wondering the best way to bind the combobox from within an ItemsControl
I initially was just having issues getting the players to show up in the combobox..but I solved that by doing the code below.
I found my first issue of just binding the items source to the combo box from within an items control.
I had to set the bindings to look like this.
ItemsSource="{Binding DataContext.PlayerList, ElementName=ItemsControlNBATeams}"
so i had to set the name of the items control and use that in the element name and set the path = to DataContext.PlayerList. this now brings up the items in my combo box..what it doesnt do is set the selecteditem of my combo box.
Not very clear about your you are asking but does this answer your question
<ListBox ItemsSource="{Binding}" x:Name="ListBox1"></ListBox>
<TextBox Text="{Binding SelectedItem, ElementName=ListBox1}"> </TextBox>