在一般的Page裏面，我們通過VisualStateManager，可以根據窗體的寬度，來調整一些控件大小。

        <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>

擋在UserControl裏面使用的時候，需要註意下VisualStateManager需要放在根控件的裏面，比如定義Grid

<Grid>
<VisualStateManager.VisualStateGroups>

<VisualStateManager.VisualStateGroups/>

其他控件。。。
<Grid/>

這樣自適應才會起作用。

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

UWP UserControl 不會自適應大小