在 .net Maui 应用程序中，我遇到了以下问题：我的集合视图在调试模式下运行良好，但在发布模式下，集合视图只显示一个白色矩形，而不是一张图片和两个标签。onClick 函数正常工作：
这是 xaml 代码：
<ContentPage xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
xmlns:vm="clr-namespace:VegaMaui"
xmlns:model="clr-namespace:VegaMaui.Model"
x:Class="VegaMaui.MenuDetails" x:DataType="vm:MenuDetailsViewModel"
Title="Ապրանքներ"
BackgroundColor="#f9f9f9">
<CollectionView
RemainingItemsThreshold="5"
RemainingItemsThresholdReachedCommand="{Binding LoadMoreS}"
SelectionMode="Single"
SelectionChanged="OnProdSelectionChanged"
ItemsSource="{Binding ProdListS}"
x:Name="prodcollect">
<CollectionView.ItemsLayout>
<GridItemsLayout Orientation="Vertical"
Span="2" />
</CollectionView.ItemsLayout>
<CollectionView.ItemTemplate>
<DataTemplate x:DataType="model:ProductImg">
<Grid Margin="5,5,5,5" Padding="1" >
<Grid.RowDefinitions>
<RowDefinition Height="Auto" />
<RowDefinition Height="Auto" />
<RowDefinition Height="Auto" />
<RowDefinition Height="Auto" />
</Grid.RowDefinitions>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*" />
</Grid.ColumnDefinitions>
<Image
Grid.Row="0"
Grid.Column="0"
Source= "{Binding firstPicture}"
Aspect="AspectFill"/>
<Label Grid.Row="1"
Grid.Column="0"
FontAttributes="Bold"
BackgroundColor="White"
LineBreakMode="WordWrap"
Text="{Binding product_Name}"
VerticalOptions="Start" />
<Label Grid.Row="2"
Grid.Column="0"
FontAttributes="Bold"
LineBreakMode="WordWrap"
BackgroundColor="White"
Text="{Binding product_DisPrice, StringFormat='{0:F0} դր.'}"
TextColor ="Red" FontSize="Default"
VerticalOptions="Start" />
<Label Grid.Row="3"
Grid.Column="0"
LineBreakMode="WordWrap"
BackgroundColor="White"
IsVisible="{Binding IsShowMode}"
Text="{Binding product_Price, StringFormat='{0:F0} դր.'}"
TextColor="#40414a" FontSize="Default"
TextDecorations="Strikethrough"
VerticalOptions="Start" />
</Grid>
</DataTemplate>
</CollectionView.ItemTemplate>
</CollectionView>
</ContentPage>
这是 ViewModel：
namespace VegaMaui
{
public class MenuDetailsViewModel : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
private int startindex = 1;
private int endindex = 10;
private string SubGrInd = "";
private readonly VegaApi ApiControl;
private void OnPropertyChanged(string propertyName) =>
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
public MenuDetailsViewModel(string SubGroup)
{
SubGrInd = SubGroup;
ApiControl = new();
// Task.Run(() => this.LoadData(SubGroup)).Wait();
ProdListS = new ObservableCollection<Model.Product>();
new Thread(() =>
{
LoadDataS();
}).Start();
}
public async Task LoadDataS()
{
var data = await ApiControl.GetMenuDetAsync(SubGrInd, startindex,endindex);
ProdListS = new ObservableCollection<Model.Product>(data);
PropertyChanged.Invoke(this,new PropertyChangedEventArgs(nameof(ProdListS)));
}
public ICommand LoadMoreS => new Command(async () =>
{
startindex += 16;
endindex += 16;
ObservableCollection<Model.Product> data = null;
new Thread(() =>
{
data= ApiControl.GetMenuDetAsync(SubGrInd, startindex, endindex).Result;
foreach (var item in data)
{
ProdListS.Add(item);
PropertyChanged.Invoke(this, new PropertyChangedEventArgs(nameof(ProdListS)));
}
}).Start();
});
public ObservableCollection<Model.Product> ProdListS { get; set; }
}
}
}
public async Task LoadDataS()
{
var data = await ApiControl.GetMenuDetAsync(SubGrInd, startindex,endindex);
ProdListS = new ObservableCollection<Model.Product>(data);
PropertyChanged.Invoke(this,new PropertyChangedEventArgs(nameof(ProdListS)));
}
public ICommand LoadMoreS => new Command(async () =>
{
startindex += 16;
endindex += 16;
ObservableCollection<Model.Product> data = null;
new Thread(() =>
{
data= ApiControl.GetMenuDetAsync(SubGrInd, startindex, endindex).Result;
foreach (var item in data)
{
ProdListS.Add(item);
PropertyChanged.Invoke(this, new PropertyChangedEventArgs(nameof(ProdListS)));
}
}).Start();
});
public ObservableCollection<Model.Product> ProdListS { get; set; }
}
}
公共部分类 MenuDetails：ContentPage { public string[] ImgList;
private MenuDetailsViewModel _mdvm;
public MenuDetails(string subGID)
{
BindingContext = _mdvm = new MenuDetailsViewModel(subGID);
InitializeComponent();
}
async void OnProdSelectionChanged(object sender, SelectionChangedEventArgs e)
{
Model.Product prodItem = this.prodcollect.SelectedItem as Model.Product;
int id_Param = prodItem.product_Id;
VegaApi ApiControl = new();
List<Model.ProdParams> ParamList = await ApiControl.GetParamDetAsync(id_Param.ToString());
ProdInformation ProfilePage = new ProdInformation();
ProfilePage.Title = this.Title;
ProfilePage.BindingContext = prodItem;
VerticalStackLayout PropsStack = ProfilePage.FindByName<VerticalStackLayout>("InfoLayout");
//Label NmLabel = ProfilePage.FindByName<Label>("prodname");
//NmLabel.Text = prodItem.product_Name;
//Label PrLabel = ProfilePage.FindByName<Label>("prodprice");
//PrLabel.Text = prodItem․+ " դր.";
// Adding Images carousel view
string[] picarray = prodItem.product_PicturePath.Split('@');
System.Collections.ObjectModel.ObservableCollection<Promo> Data = new System.Collections.ObjectModel.ObservableCollection<Promo>();
Data.Add(new Promo() { ImgSource =prodItem.firstPicture});
if (picarray.Count() > 1)
{
for (int k = 1; k < picarray.Count(); k++)
{
if (picarray[k] != null && picarray[k].Length > 3)
{
Data.Add(new Promo() { ImgSource = "https://vega.am/image/"+ picarray[k] });
}
}
}
CarouselView CurCarousel= ProfilePage.FindByName<CarouselView>("pcarousel");
CurCarousel.ItemsSource = Data;
// StackLayout slayout = new StackLayout();
// PropsStack.Add(primage);
List<int> TitleIds = (from el in ParamList select el.Title_Id).Distinct().ToList();
if (TitleIds != null && TitleIds.Count > 0)
{
for (int j = 0; j<TitleIds.Count; j++)
{
List<Model.ProdParams> subLst= ParamList.Where(p => p.Title_Id == TitleIds[j]).ToList();
if(subLst != null && subLst.Count > 0)
{
Label ltitle= new Label();
ltitle.Text = subLst[0].Title_Name;
ltitle.FontSize = 18;
ltitle.TextColor = Color.FromRgb(16, 26, 175);
ltitle.Padding = new Thickness(3, 5, 3, 5);
ltitle.HorizontalOptions = LayoutOptions.Start;
PropsStack.Add(ltitle);
Grid CurGrid = new Grid
{
ColumnDefinitions =
{
new ColumnDefinition{Width = new GridLength(5, GridUnitType.Star)},
new ColumnDefinition{Width = new GridLength(3, GridUnitType.Star)}
}
};
for (int q=0;q< subLst.Count;q++)
{
CurGrid.AddRowDefinition(new RowDefinition());
CurGrid.Add(new Label
{
Text = subLst[q].Param_Name+" ",
LineBreakMode = LineBreakMode.WordWrap,
MaxLines =2,
HorizontalOptions = LayoutOptions.Start,
VerticalOptions = LayoutOptions.Center
},0,q);
CurGrid.Add(new Label
{
Text = subLst[q].Param_Value,
LineBreakMode = LineBreakMode.WordWrap,
MaxLines = 2,
HorizontalOptions = LayoutOptions.Start,
VerticalOptions = LayoutOptions.Center
},1,q);
}
PropsStack.Add(CurGrid);
}
}
}
await Navigation.PushAsync(ProfilePage);
}
}