Why am I getting a "Unable to find suitable setter or adder" error when defining a LinearGradientBrush in my <UserControl.Resources>?

Hi:

I’m running into issues defining a LinearGradientBrush in my <UserControl.Resources> in my UserControl.

Here is the XAML Definition:

<UserControl x:Class="SampleViews.SplashView"
             xmlns="https://github.com/avaloniaui"
             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:views="clr-namespace:SampleViews"             
             mc:Ignorable="d" >

  <UserControl.Resources>
    <LinearGradientBrush x:Key="LGB1" EndPoint="1,0.5" StartPoint="0,0.5">
      <GradientStop Color="#3F000000" Offset="0"/>
      <GradientStop Offset="1"/>
    </LinearGradientBrush>
  </UserControl.Resources>
     
  <Grid>
    <Grid.ColumnDefinitions>
      <ColumnDefinition Width=".2*" />
      <ColumnDefinition Width=".6*" MinWidth="300"/>
      <ColumnDefinition Width=".2*"/>
    </Grid.ColumnDefinitions>
    <Border Grid.Column="0" Background="{StaticResource LGB1}"></Border>
  </Grid>
</UserControl>

Here is the error message:

Error XAMLIL Unable to find suitable setter or adder for property Resources of type Avalonia.Styling:Avalonia.StyledElement for argument Avalonia.Visuals:Avalonia.Media.LinearGradientBrush, available setter parameter lists are: Avalonia.Controls.IResourceDictionary System.Collections.Generic.KeyValuePair`2<System.Object,System.Object>

I should be able to define this resource within the UserControl.Resources to be used throughout the page, correct?

Am I doing something wrong here?

Thanks, JohnB

[jp2masa]

I think the problem is you wrote x:key but it’s x:Key.

[chenjing1294]

I have the same problem：

<Window xmlns="https://github.com/avaloniaui"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        x:Class="Avalonia.NETCoreMVVMApp1.Views.MainWindow"
        Icon="/Assets/avalonia-logo.ico"
        Title="Controls" Width="250" Height="150">
  <!--FontFamily="Microsoft YaHei"-->
  <Window.Resources>
    <SolidColorBrush x:Key="Warning">Yellow</SolidColorBrush>
  </Window.Resources>
  <Grid VerticalAlignment="Center" HorizontalAlignment="Center">
    <StackPanel>
      <StackPanel.Resources>
        <Bitmap x:key="Play">
          <x:Arguments>
            <x:String>/Assets/play.png</x:String>
          </x:Arguments>
        </Bitmap>
        <Bitmap x:key="Pause">
          <x:Arguments>
            <x:String>/Assets/pause.png</x:String>
          </x:Arguments>
        </Bitmap>
      </StackPanel.Resources>
      <Button Width="160">My Button</Button>
      <Button Width="200" Foreground="White" Background="Red">White text, red background</Button>

      <Button Name="PlayButton" HorizontalAlignment="Center" Width="36" Command="{Binding PlayCommand}">
        <Panel>
          <Image Source="{StaticResource Play}" IsVisible="{Binding !IsPlaying}" Width="20"
                 Height="20" VerticalAlignment="Center" HorizontalAlignment="Center" />
          <Image Source="/Assets/pause.png" IsVisible="{Binding IsPlaying}" Width="20"
                 Height="20" VerticalAlignment="Center" HorizontalAlignment="Center" />
        </Panel>
      </Button>
    </StackPanel>
  </Grid>
</Window>

error:

  MainWindow.axaml(13, 10): [XAMLIL] Unable to find suitable setter or adder for property Resources of type Avalonia.Styling:Avalonia.StyledElement for argument Avalonia.Visuals:Avalonia.Media.Imaging.Bitmap, available setter parameter lists are:
Avalonia.Controls.IResourceDictionary
System.Collections.Generic.KeyValuePair`2<System.Object,System.Object>
System.Collections.Generic.KeyValuePair`2<TKey,TValue> 第 13 行，位置 10。