<ResourceDictionary xmlns=" http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
                    xmlns:x=" http://schemas.microsoft.com/winfx/2006/xaml" 
                    xmlns:local="clr-namespace:Keyboard_Standard;assembly=Keyboard_Standard" >

    <Style x:Key="{ComponentResourceKey TypeInTargetAssembly={x:Type local:Keyboard_Standard}, 
                ResourceId=Button_1_Content}" >

        <Setter Property="Button.Content">
            <Setter.Value>

                   ............................................................

            </Setter.Value>
        </Setter>
    </Style>
</ResourceDictionary>

<Window x:Class="NoName1.MainWindow"
        xmlns=" http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
        xmlns:x=" http://schemas.microsoft.com/winfx/2006/xaml" 
        Title="MainWindow" Height="350" Width="525"
        xmlns:res="clr-namespace:Keyboard_Standard;assembly=Keyboard_Standard">

    <Window.Resources>
        <SolidColorBrush x:Key="Red">Red</SolidColorBrush>
    </Window.Resources>
        
    <Grid>

        ........................................

            <Button Grid.Row="0" Width="150" Height="50"
                    Style="{DynamicResource {ComponentResourceKey TypeInTargetAssembly={x:Type res:Keyboard_Standard}, 
                        ResourceId=Button_1_Content}}"></Button>

            <Button Grid.Row="1" Width="150" Height="50"
                    Style="{DynamicResource {ComponentResourceKey TypeInTargetAssembly={x:Type res:Keyboard_Standard}, 
                        ResourceId=Button_1_Content}}"></Button>
                  ..........................................