【发布时间】：2019-03-01 03:27:07
【问题描述】：
我想在ListView 中添加一个页脚，并在其各自的列许可证和扫描中添加两列的总和，我发现了类似的内容 (Here)，但如果我添加，页脚没有显示在 GridView 中添加 4 列，然后显示页脚行，但没有任何值。GridViewColumnHeader 包含我也想应用于页脚的样式（我没有粘贴它以提供 Minimal , 功能示例）
xaml
<Window x:Class="WpfApp2.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:local="clr-namespace:WpfApp2"
xmlns:system="clr-namespace:System;assembly=mscorlib"
xmlns:utils="Helper"
mc:Ignorable="d"
Title="MainWindow"
Height="450"
Width="800">
<Window.DataContext>
<local:ViewModel />
</Window.DataContext>
<Window.Resources>
<CollectionViewSource x:Key="ViewSource"
Source="{Binding DataList}">
<CollectionViewSource.GroupDescriptions>
<PropertyGroupDescription PropertyName="ToOrder" />
</CollectionViewSource.GroupDescriptions>
</CollectionViewSource>
</Window.Resources>
<Grid>
<ListView ScrollViewer.HorizontalScrollBarVisibility="Disabled"
ItemsSource="{Binding Source={StaticResource ViewSource}}">
<ListView.GroupStyle>
<GroupStyle>
<GroupStyle.ContainerStyle>
<Style TargetType="{x:Type GroupItem}">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type GroupItem}">
<DockPanel>
<Grid DockPanel.Dock="Bottom">
<Grid.Resources>
<local:SumConverter x:Key="sumConverter" />
</Grid.Resources>
<Grid.RowDefinitions>
<RowDefinition/>
<RowDefinition/>
</Grid.RowDefinitions>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="{Binding ElementName=Col1, Path=ActualWidth}"/>
<ColumnDefinition Width="{Binding ElementName=Col2, Path=ActualWidth}"/>
<ColumnDefinition Width="{Binding ElementName=Col3, Path=ActualWidth}"/>
</Grid.ColumnDefinitions>
<TextBlock Grid.Row="1"
Text="Sum: "
FontWeight="Bold" />
<TextBlock Grid.Column="1"
Grid.Row="1"
Text="{Binding Path=Items, Converter={StaticResource sumConverter}, ConverterParameter=1}"/>
<TextBlock Grid.Column="2"
Grid.Row="1"
Text="{Binding Path=Items, Converter={StaticResource sumConverter}, ConverterParameter=2}"/>
<Line Grid.Column="0"
Grid.Row="0"
Grid.ColumnSpan="3"
Stroke="Black"
X2="500"
Fill="Black"
VerticalAlignment="Center" />
</Grid>
<ItemsPresenter />
</DockPanel>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</GroupStyle.ContainerStyle>
</GroupStyle>
</ListView.GroupStyle>
<ListView.View>
<GridView x:Name="OverviewGridView">
<GridViewColumn DisplayMemberBinding="{Binding Date, StringFormat=dd.MM.yyyy}"
Header="Date"
x:Name="Col1"/>
<GridViewColumn DisplayMemberBinding="{Binding LicenseCount}"
Header="Licenses"
x:Name="Col2"/>
<GridViewColumn DisplayMemberBinding="{Binding ScansCount}"
Header="Scans"
x:Name="Col3"/>
</GridView>
</ListView.View>
</ListView>
</Grid>
</Window>
视图模型
namespace WpfApp2
{
using System;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Linq;
using System.Runtime.CompilerServices;
using WpfApp2.Annotations;
public class OverView
{
public int ToGroup { get; set; } = 1;
public DateTime Date { get; set; }
public int LicenseCount { get; set; }
public int ScansCount { get; set; }
}
public class ViewModel : INotifyPropertyChanged
{
private int _totalLicenses;
private ObservableCollection<OverView> _dataList;
private int _totalScans;
public ViewModel()
{
OverView a = new OverView
{
Date = DateTime.Now.Subtract(new TimeSpan(1, 0, 0, 0)),
LicenseCount = 2,
ScansCount = 7
};
OverView b = new OverView
{
Date = DateTime.Now.Subtract(new TimeSpan(5, 0, 0, 0)),
LicenseCount = 3,
ScansCount = 2
};
OverView c = new OverView { Date = DateTime.Now, LicenseCount = 5, ScansCount = 4 };
OverView d = new OverView
{
Date = DateTime.Now.Subtract(new TimeSpan(7, 0, 0, 0)),
LicenseCount = 1,
ScansCount = 3
};
DataList = new ObservableCollection<OverView> { a, b, c, d };
TotalLicenses = DataList.Sum(overview => overview.LicenseCount);
TotalScans = DataList.Sum(overview => overview.ScansCount);
}
public event PropertyChangedEventHandler PropertyChanged;
public ObservableCollection<OverView> DataList
{
get => _dataList;
set
{
_dataList = value;
OnPropertyChanged();
}
}
public int TotalLicenses
{
get => _totalLicenses;
set
{
_totalLicenses = value;
OnPropertyChanged();
}
}
public int TotalScans
{
get => _totalScans;
set
{
_totalScans = value;
OnPropertyChanged();
}
}
[NotifyPropertyChangedInvocator]
protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null) =>
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
}
}
求和转换器
namespace WpfApp2
{
#region Using
using System;
using System.Collections.Generic;
using System.Globalization;
using System.Windows.Data;
#endregion
public class SumConverter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
{
int sum = 0;
if (value is IEnumerable<object> total)
{
foreach (object o in total)
{
if (o is OverView overview)
{
int col = int.Parse((string)parameter);
sum += col == 1 ? overview.LicenseCount : overview.ScansCount;
}
}
return sum;
}
return 0;
}
public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture) => 1;
}
}
提前致谢！
编辑，经过进一步测试，我成功地在 Overview 对象中创建了一个新属性以对其进行分组，然后使用转换器对我需要的列求和。 结果如下：代码随解决方案更新。
【问题讨论】：
-
我不确定您在 ui 中显示信息的位置。您的意思是将总和作为一行添加到 Datalist 中吗？因为那没有发生。还是您的意思是将 ui 元素放在网格下方的 xaml 中以显示视图模型的总数？因为我也没有在 xaml 中看到这种情况。我错过了什么吗？
-
正好是第二个，我需要在 GridView 下方显示另一行，其中包含 LicenseCount 和 ScanCount 列的总和
-
我已更新我的问题以添加预期视图
-
您是否考虑在您的
DataList集合中添加一个“sum”项来显示列的总和？ -
好的，我看到了更新。但是您的 Path 指向的 Columns 属性在哪里？