为什么引用ListCollectionView的ComboBox.ItemsSource更改ComboBox.SelectedItem行为?

问题描述

说我有3个 ComboBox 控件.每个 ItemsSource 都引用相同的产品主列表.每个 SelectedItem 都引用另一个选定产品列表的单独数组索引.这一切都很好，程序可以按预期工作.

Say I have 3 ComboBox controls. Each ItemsSource references the same master list of products. Each SelectedItem references a separate array index of another list of selected products. This all works great, the program works as expected.

现在说我想过滤产品的主列表(例如，仅包含特定字符串"berry"的产品).将ItemsSource从Products更改为ProductsView会导致两件事:

Now say I want to filter the master list of products (for example, only those containing a specific string "berry"). Changing the ItemsSource from Products to ProductsView results in 2 things:

1. 组合框确实已正确过滤
2. 每当做出选择时，所有组合框都将设置为最后一个选择

这是代码.尝试在 ItemsSource ="{Binding Path = ProductsView}" 和 ItemsSource ="{Binding Path = Products}"

MainWindow.xaml:

MainWindow.xaml:

<Window x:Class="WpfApplication2.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow" Height="350" Width="525">
    <StackPanel>
        <ComboBox ItemsSource="{Binding Path=ProductsView}" SelectedItem="{Binding Path=SelectedProducts[0]}" />
        <ComboBox ItemsSource="{Binding Path=ProductsView}" SelectedItem="{Binding Path=SelectedProducts[1]}" />
        <ComboBox ItemsSource="{Binding Path=ProductsView}" SelectedItem="{Binding Path=SelectedProducts[2]}" />
    </StackPanel>
</Window>

MainWindow.xaml.cs:

MainWindow.xaml.cs:

using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Windows;
using System.Windows.Data;

namespace WpfApplication2
{
    public partial class MainWindow : Window
    {
        public List<Product> Products { get; set; }
        public ListCollectionView ProductsView { get; set; }
        public ObservableCollection<Product> SelectedProducts { get; set; }

        public MainWindow()
        {
            Products = new List<Product>();
            Products.Add(new Product { Name = "Apple" });
            Products.Add(new Product { Name = "Orange" });
            Products.Add(new Product { Name = "Banana" });
            Products.Add(new Product { Name = "Pear" });
            Products.Add(new Product { Name = "Strawberry" });
            Products.Add(new Product { Name = "Raspberry" });

            ProductsView = new ListCollectionView(Products);
            ProductsView.Filter = (x) => (x as Product).Name.Contains("berry");

            SelectedProducts = new ObservableCollection<Product>();
            SelectedProducts.Add(null);
            SelectedProducts.Add(null);
            SelectedProducts.Add(null);

            InitializeComponent();
            DataContext = this;
        }
    }

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

        public override string ToString()
        {
            return Name;
        }
    }
}

推荐答案

使用视图时，SelectedItem与CurrentItem同步.要取消同步集属性:

When using a view the SelectedItem is synchronized with the CurrentItem. To suppress the synchronization set property:

IsSynchronizedWithCurrentItem="False"

在组合框上.

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