Access a resource via fully qualified object name instead of string

Question

I am changing a control's style at run-time. Say changing a textbox to read-only (and thus changing other properties on the textbox affecting the display) if the user is in "review mode".

Let's say I have a style in the Application Resources.

    <Style x:Key="ReadOnlyTextBoxStyle" TargetType="{x:Type TextBox}">
        <Setter Property="BorderBrush" Value="Black"/>
        <Setter Property="BorderThickness" Value="1"/>
        <Setter Property="Focusable" Value="False"/>
        <Setter Property="Cursor" Value="Arrow"/>
        <Setter Property="Background" Value="White"/>
        <Setter Property="IsReadOnly" Value="True"/>
        <Setter Property="TextBlock.FontWeight" Value="Bold"/>
        <Setter Property="ScrollViewer.CanContentScroll" Value="True"/>
        <Setter Property="VerticalScrollBarVisibility" Value="Visible"/>
        <Setter Property="TextWrapping" Value="Wrap"/>
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate>
                    <Border x:Name="Bd" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" SnapsToDevicePixels="True" Background="{TemplateBinding Background}">
                        <ScrollViewer Name="PART_ContentHost"/>
                    </Border>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>

I've found several approaches to referencing a resource in code-behind via a string, e.g.

myTextBox.Style = (Style).Resources["ReadOnlyTextBoxStyle"];

But I can't find an example of accessing a resource via something like this:

myControl.Style = (Style).Resources[nameOf(IsThere.Some.Way.To.Get.QualifiedReferenceToStyleResourceKey)];

If I use something like:

myControl.Style = (Style).Resources["ReadOnlyTextBoxStyle"];

and then I update the key to a new string, like "ReadOnlyTextBoxStyleModified" then I have to change it everywhere I reference it in code. If I miss one of the replacements, I won't get an error until run-time. I'd prefer to see the error at compile time if possible.

The answer in the below linked question suggested using a named constant, but then didn't provide an example. That seems like it would accomplish what I am going for, but I don't understand how to implement his comment which said

"Also, a good practice is to create a string constant which maps the name of your key in the resource dictionary (so that you can change it at only one place)."

Accessing a resource via codebehind in WPF

I guess Resources work with the x:key value only. Moreover changing the style at runtime may not require code behind (for quiet some things). You can use Triggers. — Prateek Shrivastava, Feb 13 '20 at 22:49
@PrateekShrivastava thanks for your response. Even using a string that won't notify me of an error until run-time would be cleaner than using trigger for what I'm trying to do. — D. M., Feb 13 '20 at 22:58
@Clemens, I did see the second comment on the answer. The commentator was asking the answer-poster to elaborate but the answer-poster didn't respond. I was asking to see if anyone knows what the answer-poster was talking about. If he called it a good practice, I presume it is something he had done before. — D. M., Feb 13 '20 at 23:00
@Clemens, thanks for your response. So then are you saying that there is no way to access a resource in code using a qualified reference? I have to use a string of the resource key to refer to it in code? — D. M., Feb 13 '20 at 23:18

score 1 · Accepted Answer · answered Feb 13 '20 at 23:18

You may create a class with static string members for you resource keys, like

public static class ResourceKeys
{
    public static string Key1 = "Key1";
}

then declare a resource with such a key, for example

<Window.Resources>
    <SolidColorBrush x:Key="{x:Static local:ResourceKeys.Key1}" Color="Red"/>
</Window.Resources>

and use that resource by its key like

<Grid Background="{StaticResource ResourceKey={x:Static local:ResourceKeys.Key1}}">

or like

grid.Background = (Brush)FindResource(ResourceKeys.Key1);

yes, something like "grid.Background = (Brush)FindResource(ResourceKeys.Key1); " is just what I was going for — D. M., Feb 13 '20 at 23:20

Access a resource via fully qualified object name instead of string

1 Answers1