WPF 设置平均布局 如果隐藏的话，能够自动扩展

<UniformGrid Grid.Row="2" Columns="1">
	<Grid HorizontalAlignment="Stretch" VerticalAlignment="Stretch"/>
	<Grid HorizontalAlignment="Stretch" VerticalAlignment="Stretch"/>
	<Grid HorizontalAlignment="Stretch" VerticalAlignment="Stretch"/>
</UniformGrid >

<UniformGrid Grid.Row="2" Rows="1">
	<Grid HorizontalAlignment="Stretch" VerticalAlignment="Stretch"/>
	<Grid HorizontalAlignment="Stretch" VerticalAlignment="Stretch"/>
	<Grid HorizontalAlignment="Stretch" VerticalAlignment="Stretch"/>
</UniformGrid >