WPF Binding Errors (System.Windows.Data Error 4)

Question

Hello,

I am experiencing a problem with a WPF ListView control. I get a lot of the following errors:



/////
System.Windows.Data Error: 4 : Cannot find source for binding with reference 'RelativeSource FindAncestor, AncestorType='System.Windows.Controls.ItemsControl', AncestorLevel='1''. BindingExpression:Path=HorizontalContentAlignment; DataItem=null; target element is 'ListViewItem' (Name=''); target property is 'HorizontalContentAlignment' (type 'HorizontalAlignment')
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 'ListViewItem' (Name=''); target property is 'VerticalContentAlignment' (type 'VerticalAlignment')
/////

I have a System.Windows.Controls.ListView control in my XAML file (say: file1.xaml):

<ListView HorizontalContentAlignment="Left" VerticalContentAlignment="Top" HorizontalAlignment="Left" VerticalAlignment="Top" Margin="10,10,0,0" Name="lvSomething" Width="650" Height="320" />

And somewhere in a loop in the file1.xaml.cs file, I do this:

var col = new GridViewColumn();
var bnd = new Binding(string.Format("[{0}]", i));

bnd.Mode = BindingMode.OneWay;

col.Header = someArrayWithHeaderStrings[i];
col.DisplayMemberBinding = bnd;

gridView.Columns.Add(col);

And somewhere else I add items:

var lvi = new ListViewItem();

lvi.Content = new string[] { "a", "b" };

lvSomething.Items.Add(lvi);

So I have no idea what I should do in order to get rid of these errors.


Thanks in advance,

JFR

Answer 1

For me your code seems to be ok.

Do you bind HorizontalContentAlignment in a ControlTemplate?

Answer 2

Well, I actually didn't...

So I made this:

<ListView HorizontalContentAlignment="Left" VerticalContentAlignment="Top" HorizontalAlignment="Left" VerticalAlignment="Top" Margin="10,10,0,0" Name="lvSomething" Width="650" Height="320">
	<Style TargetType="ListView">
		<Setter Property="Template">
			<Setter.Value>
				<ControlTemplate TargetType="ListView">
					<ContentPresenter HorizontalAlignment="Left" VerticalAlignment="Top"></ContentPresenter>
				</ControlTemplate>
			</Setter.Value>
		</Setter>
	</Style>
</ListView>

But now I get a whole different error (less than before, though):

System.Windows.Data Error: 39 : BindingExpression path error: '[]' property not found on 'object' ''Style' (HashCode=13)'. BindingExpression:Path=[0]; DataItem='Style' (HashCode=13); target element is 'TextBlock' (Name=''); target property is 'Text' (type 'String')

I get about 7 of these in comparison with something like 30 of the first errors I mentioned.

But still I can't seem to fix it!

Answer 3

This is a "known" issue, and happens to all user controls that contain dynamically created lists (all item controls, even comboboxes, menus, etc).

For more information, see this thread.

Summary: Ignore these binding errors, it's a timing issue in WPF itself.

---

Geert van Horrik - CatenaLogic
Visit my blog: http://blog.catenalogic.com

Looking for a way to deploy your updates to all your clients? Try Updater!

Answer 4

Bedankt.

Ik kan leven met die foutmelding, maar het zorgt er wel voor dat m'n hele output window vol komt te staan...

:-)

Answer 5

Volgende keer gewoon Engels gebruiken, dan snapt de rest er ook nog iets van ;)

Yes, that is the reason why we have developed a custom output window that files the non-interesting errors (and shows the errors in red, warnings in orange, etc).

---

Geert van Horrik - CatenaLogic
Visit my blog: http://blog.catenalogic.com

Looking for a way to deploy your updates to all your clients? Try Updater!