首先LinearGradientBrush 画刷竟然包含Trsanslate 属性也就有x，y 属性
<Path HorizontalAlignment="Center"
VerticalAlignment="Center"
StrokeThickness="25"
Data="M 100 0
C 45 0, 0 45, 0 100
S 45 200, 100 200
S 200 150, 250 100
S 345 0, 400 0
S 500 45, 500 100
S 455 200, 400 200
S 300 150, 250 100
S 155 0, 100 0">
<Path.Stroke>
<LinearGradientBrush SpreadMethod="Repeat">
<LinearGradientBrush.Transform>
<TranslateTransform x:Name="translate" />
</LinearGradientBrush.Transform>
<LinearGradientBrush.GradientStops>
<GradientStop Offset="0.00" Color="Red" />
<GradientStop Offset="0.14" Color="Orange" />
<GradientStop Offset="0.28" Color="Yellow" />
<GradientStop Offset="0.42" Color="Green" />
<GradientStop Offset="0.56" Color="Blue" />
<GradientStop Offset="0.70" Color="Indigo" />
<GradientStop Offset="0.85" Color="Violet" />
<GradientStop Offset="1.00" Color="Red" />
</LinearGradientBrush.GradientStops>
</LinearGradientBrush>
</Path.Stroke>
<Path.Triggers>
<EventTrigger>
<BeginStoryboard>
<Storyboard>
<DoubleAnimation Storyboard.TargetName="translate"
Storyboard.TargetProperty="X"
From="0" To="625" Duration="0:0:2"
RepeatBehavior="5x" />
</Storyboard>
</BeginStoryboard>
</EventTrigger>
</Path.Triggers>
</Path>
