title: Update Datagrid cell according to other cells when hit Enter
body: <p>I'm using Galasoft's <code>EventToCommand</code> as code below to update Line Total cell after user inserts price and quantity.
  Please, help me find the appropriate way to make the Line Total changes when I insert the price, quantity and hit Enter. I tried <code>InputBindings</code>, but unfortunately didn't work.</p>
  
  <p>Here is the Datagrid XAML from my View:</p>
  
  <pre><code>&lt;DataGrid  IsReadOnly="False" x:Name="_StockCardItems"  ItemsSource="{Binding InvoiceDetailsList, Mode=TwoWay}" SelectedItem="{Binding SelectedItem}"  CanUserDeleteRows="True" CanUserAddRows="False"&gt;
      &lt;i:Interaction.Triggers&gt;
          &lt;i:EventTrigger EventName="CurrentCellChanged"&gt;
              &lt;gs:EventToCommand PassEventArgsToCommand="True" Command="{Binding CurrentCellChangedCommand}"/&gt;
          &lt;/i:EventTrigger&gt;
      &lt;/i:Interaction.Triggers&gt;
  
      &lt;DataGrid.InputBindings&gt;
          &lt;KeyBinding Key="Enter" Command="{Binding CurrentCellChangedCommand}"/&gt;
      &lt;/DataGrid.InputBindings&gt;
  
      &lt;DataGrid.Columns&gt;
  
          &lt;DataGridTemplateColumn Header="Désignation" Width="400" IsReadOnly="True"&gt;
              &lt;DataGridTemplateColumn.CellTemplate  &gt;
                  &lt;DataTemplate&gt;
                      &lt;TextBlock Margin="10,2" HorizontalAlignment="Left" Text="{Binding Path=Items.Designation}" /&gt;
                  &lt;/DataTemplate&gt;
              &lt;/DataGridTemplateColumn.CellTemplate&gt;
          &lt;/DataGridTemplateColumn&gt;
  
          &lt;DataGridTemplateColumn Header="Quantité"  Width="150" IsReadOnly="False"&gt;
              &lt;DataGridTemplateColumn.CellTemplate  &gt;
                  &lt;DataTemplate&gt;
                      &lt;TextBox  Margin="10,0" HorizontalAlignment="Center" GotKeyboardFocus="TextBox_GotKeyboardFocus" GotMouseCapture="TextBox_GotMouseCapture" IsReadOnly="False"  Text="{Binding Path=Quantity, Mode=TwoWay,UpdateSourceTrigger=PropertyChanged, Converter={StaticResource RemoveDoubleZero}}"  /&gt;
                  &lt;/DataTemplate&gt;
              &lt;/DataGridTemplateColumn.CellTemplate&gt;
          &lt;/DataGridTemplateColumn&gt;
  
          &lt;DataGridTemplateColumn   Header="PU"  Width="150" &gt;
              &lt;DataGridTemplateColumn.CellTemplate &gt;
                  &lt;DataTemplate&gt;
                      &lt;TextBox  Margin="10,0" HorizontalAlignment="Center" IsReadOnly="False" GotKeyboardFocus="TextBox_GotKeyboardFocus" GotMouseCapture="TextBox_GotMouseCapture"  Text="{Binding Path=UnitePrice, Mode=TwoWay,UpdateSourceTrigger=PropertyChanged, Converter={StaticResource RemoveDoubleZero}}"  /&gt;
                  &lt;/DataTemplate&gt;
              &lt;/DataGridTemplateColumn.CellTemplate&gt;
          &lt;/DataGridTemplateColumn&gt;
  
          &lt;DataGridTemplateColumn Header="Montant HT"  Width="150" &gt;
              &lt;DataGridTemplateColumn.CellTemplate &gt;
                  &lt;DataTemplate&gt;
                      &lt;TextBlock Margin="10,2" HorizontalAlignment="Right" Text="{Binding Path=Line_Total,Mode=TwoWay,ValidatesOnExceptions=True,ValidatesOnDataErrors=True, StringFormat=n, ConverterCulture=fr-FR}" /&gt;
                  &lt;/DataTemplate&gt;
              &lt;/DataGridTemplateColumn.CellTemplate&gt;
          &lt;/DataGridTemplateColumn&gt;
  
      &lt;/DataGrid.Columns&gt;
  &lt;/DataGrid&gt;
  </code></pre>
  
  <p>Here is the <code>CurrentCellChangedCommand</code> excute method in the ViewModel (<code>SelectedItem</code> is an EF Entity):</p>
  
  <pre><code>private void RecalculateLineTotal()
  {
      if (SelectedItem != null)
      SelectedItem.Line_Total = SelectedItem.Quantity * SelectedItem.UnitePrice;
  }
  </code></pre>
  
  <p>Thanks in advance</p>