ListDetailsView navigation data loss #3546
Description
Describe the bug
MasterDetailsView, navigation events are processed in incorrect order resulting in data loss for controls that use {x:Bind UpdateSourceTrigger=LostFocus} type binding.
Steps to Reproduce
public class MyItem
{
public string MyName { get; set; }
public string MyValue { get; set; }
}
public class ViewModel
{
public ObservableCollection<MyItem> Items { get; set; } = new ObservableCollection<MyItem>()
{
new MyItem(){ MyName = "Alice" },
new MyItem(){ MyName = "Bob" },
};
}
<Page.Resources>
<DataTemplate x:Key="ListTemplate" x:DataType="local:MyItem">
<TextBlock Text="{x:Bind MyName}" />
</DataTemplate>
<DataTemplate x:Key="DetailsTemplate" x:DataType="local:MyItem">
<StackPanel Margin="16">
<TextBlock Text="{x:Bind MyName}" FontSize="32" />
<TextBox Header="Value" Text="{x:Bind MyValue, Mode=TwoWay}" />
<TextBox Header="Dummy" />
</StackPanel>
</DataTemplate>
</Page.Resources>
<Grid>
<controls:MasterDetailsView
ItemsSource="{x:Bind ViewModel.Items}"
ItemTemplate="{StaticResource ListTemplate}"
DetailsTemplate="{StaticResource DetailsTemplate}"
NoSelectionContent="Select an item" />
</Grid>
Expected behavior
MasterDetailsView
1 ItemSelected
2 LostFocus => {x:Bind} saves data
3 Navigate
Actual Behavior
1 ItemSelected
2 Navigate => unsaved data overwritten
3 LostFocus
Screenshots
Environment
NuGet Package(s):
Microsoft.NETCore.UniversalWindowsPlatform
Microsoft.Toolkit.Uwp.UI.Controls
Package Version(s):
6.2.10
6.1.1
Windows 10 Build Number:
- [ ] Fall Creators Update (16299)
- [ ] April 2018 Update (17134)
- [ ] October 2018 Update (17763)
- [ ] May 2019 Update (18362)
- [x] May 2020 Update (19041)
- [ ] Insider Build (build number: )
App min and target version:
- [ ] Fall Creators Update (16299)
- [ ] April 2018 Update (17134)
- [x] October 2018 Update (17763)
- [ ] May 2019 Update (18362)
- [x] May 2020 Update (19041)
- [ ] Insider Build (xxxxx)
Device form factor:
- [x] Desktop
- [ ] Xbox
- [ ] Surface Hub
- [ ] IoT
Visual Studio
- [ ] 2017 (version: )
- [x] 2019 (version: 16.7.5)
- [ ] 2019 Preview (version: )