WPF 数据绑定到 XAML 中的对象实例

Question

以数据绑定为例，我使用两种方式填充列表框：一种在代码隐藏中，另一种在 Xaml 中。

在代码隐藏中，将列表框绑定到对象实例（在本例中为可观察集合“basicUsers”）相当容易。 在 Xaml 中，我没有成功绑定到实例。似乎只能绑定到一个对象（基于可观察集合的自定义类）。此对象实例中的数据可以用作 XAML 中的数据源吗？

XAML：

<Window x:Class="WpfApplication1.Window1"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:src="clr-namespace:WpfApplication1"
        Title="Window1" Height="300" Width="300">
<Window.Resources>
    <src:CustomTypeUsers  x:Key="myDataSource"/>
</Window.Resources>
<Grid>
    <ListBox Name="lbUsers" DisplayMemberPath="Name" Margin="10,10,70,141" Width="212"></ListBox>
    <ListBox Name="lbUsers2" ItemsSource="{StaticResource myDataSource}" DisplayMemberPath="Name" Margin="10,149,70,0" />
</Grid>

代码隐藏：

using System.Windows;
using System.Collections.ObjectModel;

namespace WpfApplication1
{
    /// <summary>
    /// Interaction logic for Window1.xaml
    /// </summary>
    public partial class Window1 : Window
    {
       private ObservableCollection<User> basicUsers = new ObservableCollection<User>(); 
       private CustomTypeUsers customUsers = new CustomTypeUsers(); 
       public Window1()
       {
          InitializeComponent();

          basicUsers.Add(new User() { Name = "John Doe" });
          basicUsers.Add(new User() { Name = "Jane Doe" });

          customUsers.Add(new User() { Name = "Natasha Doe" });
          customUsers.Add(new User() { Name = "Angelina Doe" });

          lbUsers.ItemsSource = basicUsers;
       }

       private void btnAddUser_Click(object sender, RoutedEventArgs e)
       {
         basicUsers.Add(new User() { Name = "New user" });
       }
    }

    public class User
    {
       public string Name { get; set; }
    }

    public class CustomTypeUsers : ObservableCollection<User>
    {
        public CustomTypeUsers()
        {
            Add(new User() { Name = "Emma Doe" });
            Add(new User() { Name = "Betty Doe" });
        }
    }
}

Answer 1

您实际上并没有使用绑定。请改用ItemsSource="{Binding Source={StaticResource myDataSource}}"。

Answer 2

经过几个小时的搜索，我找到了解决问题的方法（将其留给其他有类似启动问题的人）： -首先：将绑定 source 设置为周围的 object（在此示例中：对象是 MainWindow => DataContext = this;） -Second ：要使绑定到您的变量成为可能，请对它们进行properties。 -第三：如果你想访问更深层次的变量，也可以创建它们的属性并在 XAML 中访问它们，就像你在 c# 中所做的那样：例如：User.[1].Name.

在代码中：

using System.Windows;
using System.Collections.ObjectModel;

namespace WpfApplication2
{
/// <summary>
/// Interaction logic for Window1.xaml
/// </summary>
public partial class Window1 : Window
{
    public ObservableCollection<User>  basicUsers { get; private set; }
    public CustomTypeUsers customUsers { get; private set; } 
    public Window1()
   {
      InitializeComponent();

      basicUsers = new ObservableCollection<User>();
      basicUsers.Add(new User() { Name = "John Doe" });
      basicUsers.Add(new User() { Name = "Jane Doe" });

      customUsers = new CustomTypeUsers();
      customUsers.Add(new User() { Name = "Natasha Doe" });
      customUsers.Add(new User() { Name = "Angelina Doe" });

       DataContext = this;
   }
}

public class User
{
   public string Name { get; set; }
}

public class CustomTypeUsers : ObservableCollection<User>
{
    public CustomTypeUsers()
    {

        Add(new User() { Name = "John Doe" });
        Add(new User() { Name = "Betty Doe" });
    }
}
}

在 XAML 中：

    <Window x:Class="WpfApplication2.Window1"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:src="clr-namespace:WpfApplication2"
    Title="Window1" Height="300" Width="300">

<Window.Resources>
    <!-- source=DataContext is already set in code behind to object where collections are defined = MainWindow = this -->
    <!--    if defined in other classes use for example :   <csrc:CustomTypeUsers  x:Key="refSource"/> -->

</Window.Resources>
<Grid>
    <ListBox Name="lbUsers" ItemsSource="{Binding basicUsers}" DisplayMemberPath="Name" Margin="10,10,70,141" Width="212"></ListBox>
    <ListBox Name="lbUsers2" ItemsSource="{Binding customUsers}" DisplayMemberPath="Name" Margin="10,149,70,0" />
    <TextBlock Text="{Binding Path=customUsers.[2].Name, Mode=OneWay}" Margin="196,128,0,116"/>
</Grid>