UWP UserControl 不会自适应大小

在一般的Page里面，我们通过VisualStateManager，可以根据窗体的宽度，来调整一些控件大小。

        <VisualStateManager.VisualStateGroups>
                <VisualStateGroup x:Name="WindowStates">
                    <VisualState x:Name="PanoramicState">
                        <VisualState.StateTriggers>
                            <AdaptiveTrigger MinWindowWidth="1024"/>
                        </VisualState.StateTriggers>
                        <VisualState.Setters>
                            <Setter Target="row1.Height" Value="0"/>
                            <Setter Target="gridX.Visibility" Value="Collapsed"/>
                        </VisualState.Setters>
                    </VisualState>
                    <VisualState x:Name="WideState">
                        <VisualState.StateTriggers>
                            <AdaptiveTrigger MinWindowWidth="640"/>
                        </VisualState.StateTriggers>
                        <VisualState.Setters>
                            <Setter Target="column1.Width" Value="0"/>
                            <Setter Target="gridY.Visibility" Value="Collapsed"/>
                        </VisualState.Setters>
                    </VisualState>
                    <VisualState x:Name="NarrowState">
                        <VisualState.StateTriggers>
                            <AdaptiveTrigger MinWindowWidth="0"/>
                        </VisualState.StateTriggers>
                        <VisualState.Setters>
                            <Setter Target="column1.Width" Value="0"/>
                            <Setter Target="gridY.Visibility" Value="Collapsed"/>
                        </VisualState.Setters>
                    </VisualState>
                </VisualStateGroup>
            </VisualStateManager.VisualStateGroups>

挡在UserControl里面使用的时候，需要注意下VisualStateManager需要放在根控件的里面，比如定义Grid

<Grid>
<VisualStateManager.VisualStateGroups>

<VisualStateManager.VisualStateGroups/>

其他控件。。。
<Grid/>

这样自适应才会起作用。

查了Stackoverflow才知道的。https://stackoverflow.com/questions/38175647/uwp-visualstates-in-usercontrol