Basic setup

To setup the required resources you first have to add the following code to your App.xaml:

<Application.Resources>
    <!-- Attach default Theme -->
    <ResourceDictionary Source="pack://application:,,,/Fluent;Component/Themes/Generic.xaml" />
</Application.Resources>

After you have added the required resources you can start creating your first window containing a ribbon by creating a new window and then change the xaml code of that window to the following. You can fully reuse the provided code if you name your window “MyFirstWindow” and your project “MyFirstRibbonProject”. If you happen to choose different names you have to adjust the names “MyFirstRibbonProject” and “MyFirstWindow” to your desired names.

<Fluent:RibbonWindow x:Class="MyFirstRibbonProject.MyFirstWindow"
                     xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
                     xmlns:Fluent="urn:fluent-ribbon"
                     Title="My first RibbonWindow" 
                     Width="800" 
                     Height="600">
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto" />
            <RowDefinition Height="*" />
        </Grid.RowDefinitions>
    </Grid>
</Fluent:RibbonWindow>

Code behind for the window:

namespace MyFirstRibbonProject
{
    /// <summary>
    /// Represents the main window of the application
    /// </summary>
    public partial class MyFirstWindow
    {
        /// <summary>
        /// Default constructor
        /// </summary>
        public MyFirstWindow()
        {
            this.InitializeComponent();
        }
    }
}

Now that you have setup the window you can start adding the ribbon itself to the previously created Grid:

<Fluent:Ribbon Grid.Row="0">
    <!--Backstage-->
    <Fluent:Ribbon.Menu>
        <Fluent:Backstage>
        </Fluent:Backstage>
    </Fluent:Ribbon.Menu>
    
    <!--Tabs-->
    <Fluent:RibbonTabItem Header="Home">
        <Fluent:RibbonGroupBox Header="Group">
            <Fluent:Button Header="Green"
                           Icon="Resource-Path to your small icon for this button"
                           LargeIcon="Resource-Path to your large icon for this button" />
            <Fluent:Button Header="Grey" 
                           Icon="Resource-Path to your small icon for this button"
                           LargeIcon="Resource-Path to your large icon for this button" />
        </Fluent:RibbonGroupBox>
    </Fluent:RibbonTabItem>
</Fluent:Ribbon>

The complete XAML code for your first window should then look like this:

<Fluent:RibbonWindow x:Class="MyFirstRibbonProject.MyFirstWindow"
                     xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
                     xmlns:Fluent="urn:fluent-ribbon"
                     Title="My first RibbonWindow" 
                     Width="800" 
                     Height="600">
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto" />
            <RowDefinition Height="*" />
        </Grid.RowDefinitions>

        <Fluent:Ribbon Grid.Row="0">
            <!--Backstage-->
            <Fluent:Ribbon.Menu>
                <Fluent:Backstage>
                </Fluent:Backstage>
            </Fluent:Ribbon.Menu>
            
            <!--Tabs-->
            <Fluent:RibbonTabItem Header="Home">
                <Fluent:RibbonGroupBox Header="Group">
                    <Fluent:Button Header="Green"
                                Icon="Resource-Path to your small icon for this button"
                                LargeIcon="Resource-Path to your large icon for this button" />
                    <Fluent:Button Header="Grey" 
                                Icon="Resource-Path to your small icon for this button"
                                LargeIcon="Resource-Path to your large icon for this button" />
                </Fluent:RibbonGroupBox>
            </Fluent:RibbonTabItem>
        </Fluent:Ribbon>

        <Grid Grid.Row="1">
            <TextBlock>My first window containing a Ribbon and something else.</TextBlock>
        </Grid>
    </Grid>
</Fluent:RibbonWindow>

Continue adding content to the Backstage.