c# - WPF:ListView 中列表属性的总和

Question

我有一个对象列表，列表中的每个对象都包含第二个对象列表作为属性。我想在我的 ListView 的第二个列表中显示一个属性的总和。这是我目前拥有的。

<ListView ItemsSource="{Binding AllLineItems}" SelectedItem="{Binding CurrentLineItem}">
    <ListView.View>
        <GridView>
            <GridViewColumn DisplayMemberBinding="{Binding LineItem}" Header="Line Item" />
            <GridViewColumn DisplayMemberBinding="{Binding Description}" Header="Description" />
            <GridViewColumn Header="Quantity">
                <GridViewColumn.CellTemplate>
                    <DataTemplate>
                        <!-- I do not want to display a ComboBox I would like -->
                        <!-- to display the total of the Quantity property.   -->
                        <ComboBox ItemsSource="{Binding ShippingHistories}" DisplayMemberPath="Quantity" />
                    </DataTemplate>
                </GridViewColumn.CellTemplate>
            </GridViewColumn>
        </GridView>
    </ListView.View>
</ListView>

Answer 1

您可以使用值转换器:

using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using System.Windows;
using System.Windows.Data;

namespace WpfApplication1
{
    public class SumConverter : IValueConverter
    {
        public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
        {
            IEnumerable enumerable = value as IEnumerable;

            if (enumerable == null)
            {
                return DependencyProperty.UnsetValue;
            }

            IEnumerable<object> collection = enumerable.Cast<object>();

            PropertyInfo property = null;
            string propertyName = parameter as string;
            if (propertyName != null && collection.Any())
            {
                property = collection.First().GetType().GetProperty(propertyName);
            }

            return collection.Select(x => System.Convert.ToInt32(property != null ? property.GetValue(x) : x)).Sum();
        }

        public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
        {
            throw new NotImplementedException();
        }
    }
}

然后在您的 XAML 中:

xmlns:local="clr-namespace:WpfApplication1"
...
<Window.Resources>
    <local:SumConverter x:Key="sumConverter"></local:SumConverter>
</Window.Resources>
...
<GridViewColumn Header="Quantity">
    <GridViewColumn.CellTemplate>
        <DataTemplate>
            <TextBlock Text="{Binding ShippingHistories,Converter={StaticResource sumConverter},ConverterParameter=Quantity}" />
        </DataTemplate>
    </GridViewColumn.CellTemplate>
</GridViewColumn>

未经测试，但您明白了。