如何将 ObservableCollection 绑定到 ListView？

Question

我创建了一个 ObservableCollection 来使用 entity framework 从数据库中填充 ListViev。当我调用 fill 方法时，我最终会无休止地尝试填充集合。我有一个模型 Device_compiexity 和 Device_category，它们由 device_complexity_id 关联。我为他们创建了 VievModel，并在此基础上创建了一个已填充的集合。

我的视图模型：

class DeviceCategoryViewModel
{
    TechDContext dc = new TechDContext();
    public int Device_category_id { get; set; }
    public string Сategory_name { get; set; }
    public int Device_complexity_id { get; set; }
    public string Device_complexity_name { get; set; }

    public static DeviceCategoryViewModel DeviceCaterogyVM(DeviceCategory deviceCategory, DeviceComplexity deviceComplexity)
    {
        return new DeviceCategoryViewModel
        {
            Device_category_id = deviceCategory.Device_category_id,
            Сategory_name = deviceCategory.Category_name,
            Device_complexity_id = deviceCategory.Device_complexity_id,
            Device_complexity_name = deviceComplexity.Device_complexity_name,
        };
    }

    public DeviceCategoryViewModel()
    {
        FillDeviceCategories();
    }

    public void FillDeviceCategories()
    {
        using (TechDContext dc = new TechDContext())
        {
            var q = from cat in dc.DeviceCategories
                    join com in dc.DeviceComplexities on cat.Device_complexity_id equals com.Device_complexity_id
                    select new DeviceCategoryViewModel
                    {
                        Device_category_id = cat.Device_category_id,
                        Сategory_name = cat.Category_name,
                        Device_complexity_id = com.Device_complexity_id,
                        Device_complexity_name = com.Device_complexity_name
                    };
            deviceCategories = new ObservableCollection<DeviceCategoryViewModel>(q);
        }

    }

    private ObservableCollection<DeviceCategoryViewModel> deviceCategories;
    public ObservableCollection<DeviceCategoryViewModel> DeviceCategories
    {
        get
        {
            return deviceCategories;
        }
    }

    private static DeviceCategoryViewModel selectedDeviceCategory;
    public DeviceCategoryViewModel SelectedDeviceCategory
    {
        get
        {
            return selectedDeviceCategory;
        }
        set
        {
            selectedDeviceCategory = value;
        }
    }
}

在 window 的初始化中，我这样做：

DeviceCategoriesPanel.DataContext = new DeviceCategoryViewModel();

在 XAML 我这样做：

<Grid HorizontalAlignment="Left" Height="447" x:Name="DeviceCategoriesPanel" Margin="392,2,0,0" VerticalAlignment="Top" Width="392">
                <Label x:Name="label1_Copy2" Content="Категории устройств" HorizontalAlignment="Left" Margin="10,0,0,410" VerticalAlignment="Bottom" FontWeight="Bold" Width="188" FontSize="14"/>
                <ListView x:Name="categoriesComponentsLV" HorizontalAlignment="Right" MaxHeight="200" MinHeight="150"  Margin="0,44,10,0" Grid.Column="0" ItemsSource="{Binding DeviceCategories}" SelectedItem="{Binding SelectedDeviceCategory}" VerticalAlignment="Top" Width="372" Height="197">
                    <ListView.ItemTemplate>
                        <DataTemplate>
                            <StackPanel Margin="5">
                                <TextBlock FontSize="18" Text="{Binding Path=Category_name}" />
                                <TextBlock Text="{Binding Path=Device_complexity_name}" />
                            </StackPanel>
                        </DataTemplate>
                    </ListView.ItemTemplate>
                </ListView>
 </Grid>

Answer 1

当您新建每个设备类别视图模型时：

                select new DeviceCategoryViewModel
                {

它的构造函数将运行。它的构造函数是做什么的？

public DeviceCategoryViewModel()
{
    FillDeviceCategories();
}

那是你的问题。

因为 FillDeviceCategories 中有 linq，它会依次为它找到的每个调用 FillDeviceCategories...。这又会调用 FillDevicategories...可能不会无休止，因为您最终会堆栈溢出或一些令人讨厌的事情。

如何将 ObservableCollection 绑定到 ListView？

How to bind ObservableCollection to ListView?

c#

data-binding

wpf

entity-framework

observablecollection