WPF scroll bar on wrap panel grayed out

Question

I have read numerous related topics on this but can't find a solution. In WPF I am trying to place a vertical scroll bar on a wrap panel. I am dynamically building the wrap panel and it has labels and textboxes. Here is my wrap panel wrapped in a scroll viewer...

<ScrollViewer VerticalScrollBarVisibility="Visible" CanContentScroll="True" IsEnabled="True" AllowDrop="True">
                        <WrapPanel Orientation="Horizontal" Name="wpAddAttribute" Width="1129" IsEnabled="True" ScrollViewer.CanContentScroll="True" ScrollViewer.VerticalScrollBarVisibility="Visible"></WrapPanel>
                    </ScrollViewer>

Here is the C# code to dynamically build each row...

private void AddAttribute(object sender, RoutedEventArgs e)
        {
            wpAddAttribute.Children.Add(new Label { Content = "Attribute Name", Name = "lbNewTestAttributeNameLabel" });
            wpAddAttribute.Children.Add(new TextBox { Height = 26, Name = "tbNewTestAttributeName", Width = 75 });
            wpAddAttribute.Children.Add(new Label { Content = "Attribute Value", Name = "lbNewTestAttributeValueLabel" });
            wpAddAttribute.Children.Add(new TextBox { Height = 26, Name = "tbNewTestAttributeValue", Width = 55 });
            wpAddAttribute.Children.Add(new Label { Content = "Attribute Units", Name = "lbNewTestAttributeUnitsLabel" });
            wpAddAttribute.Children.Add(new TextBox { Height = 26, Name = "tbNewTestAttributeUnits", Width = 55 });

            wpAddAttribute.Children.Add(new Label { Content = "Attribute Minimum Value", Name = "lbNewTestAttributeMinValueLabel" });
            wpAddAttribute.Children.Add(new TextBox { Height = 26, Name = "tbNewTestAttributeMinValue", Width = 55 });
            wpAddAttribute.Children.Add(new Label { Content = "Attribute Maximum Value", Name = "lbNewTestAttributeMaxValueLabel" });
            wpAddAttribute.Children.Add(new TextBox { Height = 26, Name = "tbNewTestAttributeMaxValue", Width = 55 });

            wpAddAttribute.Children.Add(new Label { Content = "Stepping Minimum Value", Name = "lbNewTestSteppingMinValueLabel" });
            wpAddAttribute.Children.Add(new TextBox { Height = 26, Name = "tbNewTestAttributeMinValue", Width = 55 });
                        }

I do see a vertical scroll bar on the right side of the screen but it is always grayed out, even when I exceed the space I'm in. Any ideas of how to get the scrolling on/not grayed out?

Here is my wrap panel with the parent border container...

 <Border Name="bdAddTestArea" Visibility="Collapsed" Background="DeepSkyBlue" BorderThickness="2" BorderBrush="Black" CornerRadius="10"  Margin="10" Width="1130" Height="330" ScrollViewer.CanContentScroll="True">
            <StackPanel ScrollViewer.CanContentScroll="True">
                <StackPanel Orientation="Vertical" ScrollViewer.CanContentScroll="True" ScrollViewer.VerticalScrollBarVisibility="Auto">
                    <TextBlock Margin="4 0 0 0">Add a Test</TextBlock>
                    <StackPanel Orientation="Horizontal">
                        <Label Content="New Test Name:"></Label>
                        <TextBox Name="tbNewTestName" Width="75"></TextBox>
                        <Label Content="Test Estimate (in seconds):"></Label>
                        <TextBox Name="tbTestEstimate" Width="75"></TextBox>
                    </StackPanel>
                    <ScrollViewer VerticalScrollBarVisibility="Visible" CanContentScroll="True" IsEnabled="True" AllowDrop="True">
                        <WrapPanel Orientation="Horizontal" Name="wpAddAttribute" Width="1129" IsEnabled="True" ScrollViewer.CanContentScroll="True" ScrollViewer.VerticalScrollBarVisibility="Visible"></WrapPanel>
                    </ScrollViewer>
                </StackPanel>

                <StackPanel Visibility="Visible" Orientation="Horizontal" >
                </StackPanel>
                <Button Content="Add an Attribute" Click="AddAttribute" Width="96" Margin="5 5 0 0" HorizontalAlignment="Left"></Button>
                <Button Content="Save Test" Click="SaveTest" Height="20" HorizontalAlignment="Left" Margin="5 5 0 0"></Button>
                <Button Content="Return To Test Selection" Click="ReturnToSelectionPanel" Height="20" HorizontalAlignment="Left" Margin="5 5 0 0"></Button>

            </StackPanel>
        </Border>

Answer 1

Why the orientation of wrap panel is Horizontal if you want to implement it vertically, change orientation to Vertical. It is working fine here then.