GridView Items Width - xaml

Question

Got a GridView that its items width are set by the first one width(Screenshot)
How could I set some auto width for each item?
<GridView ItemsSource="{x:Bind PopularItems}" Style="{StaticResource GVStyle}" Height="230">
<GridView.ItemTemplate>
<DataTemplate x:Name="GVTemp" x:DataType="models:LessDetails">
<StackPanel>
<Image Height="180" Width="132" Source="{x:Bind Img}" />
<TextBlock Margin="4,4,0,4" HorizontalAlignment="Stretch" TextAlignment="Center"
Text="{x:Bind Name}" Style="{ThemeResource BodyTextBlockStyle}" />
</StackPanel>
</DataTemplate>
</GridView.ItemTemplate>

Answer 1

You can not auto-width each item in a GridView control, it is by designed to use the first item's size as the uniform size (ListViewItemPresenter for each items has the same size).
For the auto-size scenario, I suggest you using the StackPanel or creating a custom ItemsControl.

Answer 2

Use an ItemsStackPanel:
<GridView.ItemsPanel>
<ItemsPanelTemplate>
<ItemsStackPanel Orientation="Horizontal" VerticalAlignment="Top" HorizontalAlignment="Left" />
</ItemsPanelTemplate>
</GridView.ItemsPanel>
The only downside is that it doesn't wrap items.. For that you can use the ItemsWrapGrid but then you lose the auto-width functionality (first item determines the width of all items).
There's also the VariableSizedWrapGrid that can be used by giving items a certain ColumnSpan/RowSpan, but it's not quite the same as automatically calculating the width.
If you want the best of both world, probably you'll need to write your own custom panel.
UPDATE: For a solution that allows for both automatic width and item wrapping, you can use the WrapPanel control from the UWP Community Toolkit.