Table of Contents

Getting started

Adding dictionaries

XAML, and hence WPF, operate on resource dictionaries. These are HTML-like files that describe the appearance and various aspects of the controls.
WPF UI adds its own sets of these files to tell the application how the controls should look like.

There should be a file called App.xaml in your new application. Add new dictionaries to it using WPF UI ControlsDictionary and ThemesDictionary classes:

<Application
  ...
  xmlns:ui="http://schemas.lepo.co/wpfui/2022/xaml">
  <Application.Resources>
    <ResourceDictionary>
      <ResourceDictionary.MergedDictionaries>
        <ui:ThemesDictionary Theme="Dark" />
        <ui:ControlsDictionary />
      </ResourceDictionary.MergedDictionaries>
    </ResourceDictionary>
  </Application.Resources>
</Application>

You can choose a color theme here,
Light or Dark.

The main window

There should be a MainWindow.xaml file in your newly created application.
It contains the arrangement of the controls used and their parameters.

<Window x:Class="WpfApp1.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:WpfApp1"
        mc:Ignorable="d"
        Title="MainWindow" Height="450" Width="800">
    <Grid>

    </Grid>
</Window>

You can add a new namespace to this window to tell the interpreter that you will be using controls from somewhere, like the WPF UI library.

<Window
  ...
  xmlns:ui="http://schemas.lepo.co/wpfui/2022/xaml" />

Adding controls

To add a new control from the WPF UI library, you just need to enter its class name, prefixing it with the ui: prefix:

<Window x:Class="WpfApp1.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:ui="http://schemas.lepo.co/wpfui/2022/xaml"
        xmlns:local="clr-namespace:WpfApp1"
        mc:Ignorable="d"
        Title="MainWindow" Height="450" Width="800">
    <Grid>
      <ui:SymbolIcon Symbol="Fluent24"/>
    </Grid>
</Window>

Well...

That's it when it comes to the basics, information about individual controls can be found in documentation, rules for building a WPF application can be found in the official Microsoft documentation. You can check out how to build MVVM applications here.
If you think this documentation sucks, help improve it here.