将ObservableCollection <object>传递给UserControl

如何解决将ObservableCollection <object>传递给UserControl

我一直在试图概括将ObservableCollection传递给此处提供的UserControl的解决方案：

How to bind collection dependency property in UserControl

我将UserControl背后的代码更改为：

/// <summary>
/// Interaction logic for myUserControl1.xaml
/// </summary>
public partial class myUserControl1 : UserControl
{
    #region Public Section
    public ObservableCollection<object> UCItems
    {
        get;
        set;
    }

    #endregion
    public myUserControl1()
    {
        InitializeComponent();

        UCItems = new ObservableCollection<object>();
    }

    #region UCItemsSource Property

    public static readonly DependencyProperty UCItemsSourceProperty = 
        DependencyProperty.Register("UCItemsSource",typeof(IEnumerable),typeof(myUserControl1));

    public IEnumerable UCItemsSource
    {
        get { return (IEnumerable)GetValue(UCItemsSourceProperty); }
        set { SetValue(UCItemsSourceProperty,value); }
    }

    #endregion
}

并将TexBox更改为xaml中的DataGrid：

<UserControl x:Class="OCasDPdemo.myUserControl1"
         xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
         xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
         xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
         xmlns:local="clr-namespace:OCasDPdemo"
         mc:Ignorable="d" 
         d:DesignHeight="450" d:DesignWidth="800">
<Grid>
    <ItemsControl ItemsSource="{Binding Path=UCItemsSource,RelativeSource={RelativeSource Mode=FindAncestor,AncestorType={x:Type UserControl}}}">
        <ItemsControl.ItemTemplate>
            <DataTemplate>
                <DataGrid x:Name="myDataGrid" ItemsSource="{Binding Path=UCItemsSource.Person}"/>
            </DataTemplate>
        </ItemsControl.ItemTemplate>
    </ItemsControl>
</Grid>

我以与原始示例类似的方式填充集合：

/// <summary>
/// Interaction logic for MainWindow.xaml
/// </summary>
public partial class MainWindow : Window
{
    public ObservableCollection<Person> WindowCollection
    {
        get;
        set;
    }
    public MainWindow()
    {
        InitializeComponent();

        DataContext = this;


        var bob = new Person { FirstName = "Bob",LastName = "Brown",Age = 32.1,ID = 101 };
        var jim = new Person { FirstName = "Jim",LastName = "Green",Age = 21.0,ID = 201 };
        var mel = new Person { FirstName = "Mel",LastName = "Black",Age = 20,ID = 111 };

        WindowCollection = new ObservableCollection<Person>() {bob,jim,mel };
    }

    private void Button_Click(object sender,RoutedEventArgs e)
    {
        var sue = new Person { FirstName = "Sue",LastName = "White",Age = 64.7,ID = 101 };
        var ted = new Person { FirstName = "Ted",LastName = "Grey",Age = 18.3,ID = 191 };

        WindowCollection.Add(sue);
        WindowCollection.Add(ted);
    }
}

MainWindow xaml是：

<Grid>
    <StackPanel>
        <local:myUserControl1 UCItemsSource="{Binding Path=WindowCollection}" />
        <Button Content="Refresh" Click="Button_Click" />
    </StackPanel>
</Grid>

我得到的是空行（与人数相同），而不是带有列的网格。此设置适用于本机类型，例如长型和字符串类型（使用TextBox）。有人可以让我知道我做错了吗。

解决方法

我自己还没有尝试过，但是问题似乎出在您的Future<void> main() async { final d = await callApi(); final listTiles = <ListTile>[ ...d.as.convertToListTiles(),...d.bs.convertToListTiles(),...d.cs.convertToListTiles(),]; //TODO: do something with `listTiles` } XAML中。

在根myUserControl1内是Grid，其中ItemsControl绑定到ItemsSource。这意味着UCItemsSource将为该集合中的每个元素生成一个ItemsControl-在您的情况下，将是您的ContentPresenter s列表。

现在，将在每个Person中创建一个ContentPresenter的实例。您的DataTemplate包含一个DataTemplate。这意味着您将每DataGrid获得一个完整的DataGrid。

相反，如果您尝试使用一个Person且每个DataGrid行，那么您可能想要这样的东西：

Person