无法解析CellTemplate绑定中的符号

我有一个列表视图控件项源绑定到 Producers 财产和它的运作良好。但是当我试图添加一些数据触发器时 Cannot resolve symbol 'Up' VS警告。
代码可以工作,但我想通过显式指定绑定源来消除警告。

我试图使用relative source,但发现CellTemplate不能使用RelativeSource,因为它不是VisualTree的一部分。

<ListView ItemsSource="{Binding Producers, ElementName=This}">
    <ListView.View>
        <GridView>
            <GridViewColumn Header="Id" DisplayMemberBinding="{Binding Id}"></GridViewColumn>
            <GridViewColumn Header="Description" DisplayMemberBinding="{Binding Description}"></GridViewColumn>
            <GridViewColumn Header="Up">
                <GridViewColumn.CellTemplate>
                    <DataTemplate>
                        <TextBlock Text="{Binding Up}">
                            <TextBlock.Style>
                                <Style TargetType="TextBlock">
                                    <Style.Triggers>
                                        <DataTrigger Binding="{Binding Up}" Value="True">
                                            <Setter Property="Foreground" Value="Green"></Setter>
                                        </DataTrigger>
                                        <DataTrigger Binding="{Binding Up}" Value="False">
                                            <Setter Property="Foreground" Value="Red"></Setter>
                                        </DataTrigger>
                                    </Style.Triggers>
                                </Style>
                            </TextBlock.Style>
                        </TextBlock>
                    </DataTemplate>
                </GridViewColumn.CellTemplate>
            </GridViewColumn>
        </GridView>
    </ListView.View>
</ListView>  

This 元素定义为:

<Window x:Class="Helper.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:Helper"
        mc:Ignorable="d"
        Title="MainWindow" Height="900.731" Width="889.344"
        x:Name="This">
    <Grid>
        ...
    </Grid>
</Window>

有人能帮忙吗?