Reputation: 4042
I'm wondering is it possible to remove highlighted items with Key.Delete
, while a DropDown
is Open?
(source: iforce.co.nz)
What I've tried..
C#
private void OnKeyUpHandler(object sender, KeyEventArgs e)
{
Boolean delete = e.Key == Key.Delete;
if (sender == cbkSnpCodes && (delete && cbkSnpCodes.IsDropDownOpen))
{
cbkSnpCodes.Items.Remove(cbkSnpCodes.SelectedItem);
cbkSnpCodes.Items.Refresh();
}
}
XAML
<ComboBox ItemsSource="{Binding SnpCodeModel}" Name="cbkSnpCodes" Controls:TextboxHelper.Watermark="Enter an snp code and press enter" MaxDropDownHeight="50" KeyUp="OnKeyUpHandler" KeyDown="OnKeyDownHandler" DisplayMemberPath="SnpCode" IsEditable="True" HorizontalAlignment="Left" VerticalAlignment="Top" Text="{Binding Path=SnpCode, Mode=TwoWay}" IsReadOnly="False" Height="26" Margin="81,9,0,0" Width="223" Grid.Column="1" Grid.ColumnSpan="2" />
Binding Class SnpCodeModel
class SnpCodeModel
{
public string SnpCode { get; set; }
public SnpCodeModel(string _snpcode)
{
this.SnpCode = _snpcode;
}
}
I have also tried the solution posted by Harold Bamford on the Stackoverflow question: In a combobox, how do I determine the highlighted item (not selected item)?
private void OnKeyUpHandler(object sender, KeyEventArgs e)
{
Boolean delete = e.Key == Key.Delete;
ComboBox box = sender as ComboBox;
if (box.IsDropDownOpen && delete)
{
const BindingFlags flags = BindingFlags.NonPublic | BindingFlags.Static | BindingFlags.Instance;
PropertyInfo hl = box.GetType().GetProperty("HighlightedItem", flags);
if (hl != null)
{
String hlString = hl.GetValue(sender, null).ToString();
SnpCodeModel snp = new SnpCodeModel(hlString);
cbkSnpCodes.Items.Remove(snp);
cbkSnpCodes.Items.Refresh();
}
}
}
But it doesn't work :-( and produces this output within the System.Diagnostics;
System.Windows.Data Error: 4 : Cannot find source for binding with reference 'RelativeSource FindAncestor, AncestorType='System.Windows.Controls.ItemsControl', AncestorLevel='1''. BindingExpression:Path=VerticalContentAlignment; DataItem=null; target element is 'ComboBoxItem' (Name=''); target property is 'VerticalContentAlignment' (type 'VerticalAlignment')
The main problem with my current attempts is that because the ComboBox
is editable the item that I am trying to Delete becomes null
before it reaches cbkSnpCodes.Items.Remove
.
Is it possible to achieve the functionality I'm looking for? I haven't been able to find much on google
Upvotes: 1
Views: 602
Reputation: 6014
You are creating a new instance of SnpCodeModel with SnpCodeModel snp = new SnpCodeModel(hlString);
. Even though it has the same content, it cant be found in cbkSnpCodes, because its not the same instance as the HighlightedItem.
Try something like
if (hl != null)
{
box.Items.Remove(hl.GetValue(sender, null));
//box.Items.Refresh();
}
or override the Equals method in your SnpCodeModel:
public override bool Equals(object obj)
{
if (obj is SnpCodeModel)
return ((SnpCodeModel)obj).SnpCode == this.SnpCode
return false;
}
Upvotes: 1