这是正常的相关性属性值优先级。在图像上将其设置为＃3，在样式触发器中将其设置为较低优先级＃6。

This is the normal Dependency Property Value Precedence. Setting it on Image is at #3, while in the Style trigger is at a lower precedence of #6.

您可以改为：

<Image Name="image1" Stretch="Uniform" Source="/Affinity;component/Images/affinity_logo.png">
    <Image.Style>
        <Style TargetType="Image">
            <Setter Property="Visibility" Value="Hidden" />
            <Style.Triggers>
                <DataTrigger Binding="{Binding Items.Count, ElementName=tabcontrolworkspaces}"
                    Value="0">
                    <Setter Property="Visibility" Value="Visible" />
                </DataTrigger>
            </Style.Triggers>
        </Style>
    </Image.Style>
</Image>