.NET MAUI调试正常发布模式绑定数据不显示问题求助

调试模式下数据显示正常，但发布模式中ClassNameView自定义视图和CollectionView内的数据无法显示，仅能看到空白。已确认数据已正确加载（CollectionView行数符合预期），将自定义视图的XML直接嵌入页面时数据显示正常。

ObservationHistoryPage.xaml #

<ContentPage
    x:Class="SchoolApp.Views.ObservationHistoryPage"
    xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
    xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
    xmlns:custom="clr-namespace:SchoolApp.Custom"
    xmlns:resx="clr-namespace:SchoolApp.Resources.Strings"
    xmlns:skia="clr-namespace:SkiaSharp.Extended.UI.Controls;assembly=SkiaSharp.Extended.UI"
    xmlns:toolkit="http://schemas.microsoft.com/dotnet/2022/maui/toolkit"
    xmlns:vm="clr-namespace:SchoolApp.ViewModels"
    Title="{x:Static resx:AppResources.ObservationsHistory}"
    x:DataType="vm:ObservationHistoryPageViewModel">
    <ContentPage.Behaviors>
        <toolkit:EventToCommandBehavior Command="{Binding NavigatedToCommand}" EventName="NavigatedTo" />
    </ContentPage.Behaviors>
    <Grid>
        <custom:LoadingAndErrorView
            Display="{Binding Display}"
            ErrorDescription="{Binding ErrorMessage}"
            ErrorTitle="{Binding ErrorTitle}"
            RetryCommand="{Binding LoadInfoCommand}" />
        <ScrollView>
            <VerticalStackLayout
                Padding="10"
                IsVisible="{Binding DisplayData}"
                Spacing="10">
                <!--  Class Name  -->
                
                <custom:ClassNameView ClassName="{Binding ClassName}" />
                <Label
                    HorizontalOptions="Center"
                    Style="{StaticResource LargeLabelBold}"
                    Text="{x:Static resx:AppResources.ObservationHistory}" />
               
                <!--  Count  -->
                <HorizontalStackLayout Padding="0,0,5,0" HorizontalOptions="End">
                    <Label Style="{StaticResource MediumLabelItalic}" Text="Total:" />
                    <Label Style="{StaticResource MediumLabelItalic}" Text="{Binding ObservationCount}" />
                </HorizontalStackLayout>
                <!--  Dates  -->
                <CollectionView ItemsSource="{Binding Dates}" SelectionMode="None">
                    <CollectionView.ItemTemplate>
                        <DataTemplate>
                            <Grid Padding="10" ColumnDefinitions="80,*">
                                <Image
                                    HorizontalOptions="Center"
                                    Source="calendar"
                                    WidthRequest="68" />
                                <Label
                                    Grid.Column="1"
                                    HorizontalOptions="Center"
                                    Style="{StaticResource LargeLabelBold}"
                                    Text="{Binding ., StringFormat='{0:dd / MMMM / yyyy }'}"
                                    VerticalOptions="Center" />
                            </Grid>
                        </DataTemplate>
                    </CollectionView.ItemTemplate>
                </CollectionView>
                <!--  close button  -->
                <Button
                    Command="{Binding CloseCommand}"
                    IsVisible="{Binding IsNotBusy}"
                    Style="{x:StaticResource ButtonOutline}"
                    Text="{x:Static resx:AppResources.Close}" />
            </VerticalStackLayout>
        </ScrollView>
    </Grid>
</ContentPage>

ObservationHistoryPageViewModel.cs #

using SchoolApp.Models.Observations;

namespace SchoolApp.ViewModels
{
    [QueryProperty(nameof(Observation), nameof(Observation))]
    [QueryProperty(nameof(ClassName), nameof(ClassName))]
    public partial class ObservationHistoryPageViewModel : BaseViewModel
    {
        private readonly ObservationsService _observationsService;
        [ObservableProperty]
        ObservationStudentComplete _observation;
        
        [ObservableProperty]
        string _className;

        [ObservableProperty]
        [NotifyPropertyChangedFor(nameof(ObservationCount))]
        List<DateTime> _dates=new List<DateTime>();


        public int ObservationCount => Dates.Count;

        public ObservationHistoryPageViewModel(ObservationsService observationsService)
        {
            _observationsService = observationsService;
        }

        [RelayCommand]
        public async Task NavigatedTo()
        {
            await LoadInfo();
        }

        [RelayCommand]
        public async Task LoadInfo()
        {
            SetPageInLoadingState();
            var result = await _observationsService.GetObservationHistory(Selected.Student.IdAlumno, Selected.Organization.IsParent, Observation);
            SetDisplayAndErrorsFromResult(result);
            Dates = result.Item ?? new List<DateTime>();
            SetPageInFinishLoadingState();
        }

        [RelayCommand]
        public async Task Close()
        {
            await Shell.Current.GoToAsync("..");
        }
    }
}

ClassNameView.xaml #

<Grid
    x:Class="SchoolApp.Custom.ClassNameView"
    xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
    xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
    xmlns:custom="clr-namespace:SchoolApp.Custom"
    x:DataType="custom:ClassNameView"
    ColumnDefinitions="80,*">
    <Image Source="books" WidthRequest="60" />
    <Label
        Grid.Column="1"
        Style="{x:StaticResource LargeLabelBold}"
        Text="{Binding ClassName}"
        VerticalOptions="Center" />
</Grid>

ClassNameView.xaml.cs #

namespace SchoolApp.Custom;

public partial class ClassNameView : Grid
{
    public static readonly BindableProperty ClassNameProperty = BindableProperty.Create(nameof(ClassName)
        , typeof(string)
        , typeof(ClassNameView)
        , default(string)
        , propertyChanged: (bindable, value, newValue) => ((ClassNameView)bindable).ClassName = (string)newValue);
    public string ClassName
    {
        get => (string)GetValue(ClassNameProperty);
        set => SetValue(ClassNameProperty, value);
    }
    public ClassNameView()
    {
        InitializeComponent();
    }
}

问题原因及解决方法 #

1. 自定义视图ClassNameView绑定错误 #

发布模式下XAML编译优化会严格解析绑定规则，你的自定义视图存在两个问题：

• BindableProperty的propertyChanged回调手动给CLR属性赋值，会触发无限循环并破坏绑定同步机制。
• XAML中绑定ClassName未明确指定源为视图自身，发布模式下无法正确解析绑定上下文。

修复ClassNameView.xaml.cs：
移除propertyChanged回调，BindableProperty会自动同步CLR属性：

public static readonly BindableProperty ClassNameProperty = BindableProperty.Create(
    nameof(ClassName),
    typeof(string),
    typeof(ClassNameView),
    default(string));

public string ClassName
{
    get => (string)GetValue(ClassNameProperty);
    set => SetValue(ClassNameProperty, value);
}

修复ClassNameView.xaml：
明确绑定源为自身：

<Label
    Grid.Column="1"
    Style="{x:StaticResource LargeLabelBold}"
    Text="{Binding ClassName, Source={RelativeSource Self}}"
    VerticalOptions="Center" />

2. CollectionView的DataTemplate未指定类型 #

发布模式下未指定DataTemplate的x:DataType会导致绑定失效，需明确绑定的DateTime类型：

修复ObservationHistoryPage.xaml中的CollectionView：

<CollectionView ItemsSource="{Binding Dates}" SelectionMode="None">
    <CollectionView.ItemTemplate>
        <DataTemplate x:DataType="x:DateTime">
            <Grid Padding="10" ColumnDefinitions="80,*">
                <Image
                    HorizontalOptions="Center"
                    Source="calendar"
                    WidthRequest="68" />
                <Label
                    Grid.Column="1"
                    HorizontalOptions="Center"
                    Style="{StaticResource LargeLabelBold}"
                    Text="{Binding ., StringFormat='{0:dd / MMMM / yyyy }'}"
                    VerticalOptions="Center" />
            </Grid>
        </DataTemplate>
    </CollectionView.ItemTemplate>
</CollectionView>

3. 发布模式代码收缩优化问题 #

默认发布配置的代码收缩可能移除绑定所需元数据，需修改项目文件（.csproj）：

<PropertyGroup Condition="'$(Configuration)' == 'Release'">
    <AndroidLinkMode>SdkOnly</AndroidLinkMode>
    <MauiLinkMode>SdkOnly</MauiLinkMode>
    <EnableTrimAnalyzer>false</EnableTrimAnalyzer>
</PropertyGroup>

内容的提问来源于stack exchange，提问作者Salvador Cruz