Question

we have a wpf-window with some textboxes and a datagrid.
the textboxes descripe a parent (class a) object and the datagrid lists a collection of “childs” (class b => not derived from class a).
the childs can inherit values from the parent.

for example if the parent (class a) has a property Foo then the child object (class b) has a property Nullable which can either override the value of the parent or inherit the value of the parent.

now the datagrid should display the value in gray (if it is inherited) or in black (if the user overrides the value in the grid cell).

Unfortunatly Binding to InheritedText doesnt work. Does someone have any idea?

 <DataGridTemplateColumn.CellTemplate>
      <DataTemplate>
           <UserControls:InheritedTextBoxControl 
                 Text="{Binding Path=?}"
                 InheritedText="{Binding Path=?}" />
      </DataTemplate>
 </DataGridTemplateColumn.CellTemplate>

Thanks in advance
Tobi

–UPDATE–

xaml of InheritedTextBoxControl:

<UserControl x:Class="Com.QueoMedia.CO2Simulationstool.WPF.Utils.UserControls.InheritedTextBoxControl"
         xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
         xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
         xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
         mc:Ignorable="d"
         Width="Auto"
         Height="Auto"
         Name="cnt">

<Grid x:Name="LayoutRoot"
      Background="White">
    <TextBox TextChanged="TextBoxTextChanged"></TextBox>
    <TextBlock Name="inheritedText"
               IsHitTestVisible="False"
               Margin="4,0"
               VerticalAlignment="Center"
               Opacity="0.5"
               FontStyle="Italic"></TextBlock>
</Grid>

CodeBehind:

public partial class InheritedTextBoxControl : UserControl {

    private bool _isInherited;

    public static readonly DependencyProperty InheritedTextProperty = DependencyProperty.Register("InheritedText", typeof(String), typeof(InheritedTextBoxControl), new PropertyMetadata(""));
    public static DependencyProperty TextProperty = DependencyProperty.Register("Text", typeof(string), typeof(InheritedTextBoxControl), new PropertyMetadata(default(string)));

    public InheritedTextBoxControl() {
        InitializeComponent();
    }

    public string InheritedText {
        get { return (string)GetValue(InheritedTextProperty); }
        set {
            SetValue(InheritedTextProperty, value);
            inheritedText.Text = value;
        }
    }

    private bool IsInherited {
        get { return _isInherited; }
        set {
            _isInherited = value;
            if (value) {
                inheritedText.Opacity = 0.5;
            } else {
                inheritedText.Opacity = 0;
            }
        }
    }

    public string Text {
        get { return (string)GetValue(TextProperty); }
        set { SetValue(TextProperty, value); }
    }

    private void TextBoxTextChanged(object sender, TextChangedEventArgs e) {
        if (((TextBox)sender).Text.Length > 0) {
            IsInherited = false;

        } else {
            IsInherited = true;
        }
        Text = ((TextBox)sender).Text;
    }
}

Answer 1

If someone is interested in the solution:

we did it using a CellTemplate containing a CustomControl name MaskedTextbox that has three properties (MaskedText, Text, IsMaskTextVisible) and a CellEditingTemplate to override the data.

The values are bound to an InheritableValueViewModel.

Tobi