private void InternalEditorsInit()
{
_expressionEditor = new ConditionExpressionEditorControl(PrimaryStyleCollection.ColumnInfo);
_expressionEditor.ExpressionChanged += delegate { UpdateExpressionString(); };
var enabledBinding = new Binding(SelectedItemPropertyName)
{
Converter = new InternalStateConverter()
};
_expressionEditor.SetBinding(IsEnabledProperty, enabledBinding);
expressionGroup.Children.Add(_expressionEditor);
}
