参考：stackoverflow

问题背景

有如下代码，发现在 ImageSource="{Binding SomeImage}" 中没有绑定的当前的 DataContext

<Grid>
    <Border>
        <Border.Style>
            <Style TargetType="Border">
                <Style.Triggers>
                    <DataTrigger Binding="{Binding SomeValue, ElementName=myControl, Mode=OneWay}" Value="0">
                        <Setter Property="Background">
                            <Setter.Value>
                                <!-- 此处 Binding 没有生效 -->
                                <ImageBrush ImageSource="{Binding SomeImage}" />
                            </Setter.Value>
                        </Setter>
                    </DataTrigger>
                </Style.Triggers>
            </Style>
        </Border.Style>
    </Border>
</Grid>

解决办法

改成如下即可

<Grid>
    <Grid.Resource>
        <ImageBrush x:key="myImage" ImageSource="{Binding SomeImage}" />
        <Style x:key="myStyle" TargetType="Border">
            <Style.Triggers>
                <DataTrigger Binding="{Binding SomeValue, ElementName=myControl, Mode=OneWay}" Value="0">
                    <Setter Property="Background" Value="{StaticResource myImage}"/>
                </DataTrigger>
            </Style.Triggers>
        </Style>
    </Grid.Resource>
    <Border Style="{StaticResource myStyle}"/>
</Grid>