c# - 带有 MVVM 模式的 WPF 中的组合框列绑定(bind) (Galasoft)

Question

看在上帝的份上，我无法解决这个问题。我确实看到了这个答案:How to Bind data to DataGridComboBoxColumn in DataGrid using MVVM还有更多，但我不确定我做错了什么。这是我的想法。我有一个 DataGrid绑定(bind)到 Views收藏。每一行都由一个类 ViewWrapper 的对象表示ViewWrapper 有一个名为 ViewTemplate 的属性。类型为 ViewWrapper .所以基本上 View 包装器可以在其中存储另一个 View 包装器。现在，我想连接一个 ComboBox到 ViewWrapper 的列表中对象存储在名为 ViewTemplates 的变量中.这在 ViewModel 上可用。它包含所有可能的 View 包装器，可以将 View 模板属性设置为。现在，我想绑定(bind) SelectedItem的组合框到 ViewWrapper.ViewTemplate从 DataGrid 行。我无法让这件事发挥作用。

这是我的设置:

XAML:

<UserControl x:Class="GrimshawRibbon.Revit.Views.ViewManager.ViewManagerView"
             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:i="http://schemas.microsoft.com/expression/2010/interactivity"
             xmlns:local="clr-namespace:GrimshawRibbon.Revit.Views.ViewManager"
             xmlns:ex="clr-namespace:GrimshawRibbon.Revit.Wpf.Extensions"
             xmlns:controls="clr-namespace:MahApps.Metro.Controls;assembly=MahApps.Metro"
             xmlns:cmd="clr-namespace:GalaSoft.MvvmLight.Command;assembly=GalaSoft.MvvmLight.Platform"
             mc:Ignorable="d" 
             d:DesignHeight="300" d:DesignWidth="500">
    <UserControl.Resources>
        <ResourceDictionary>
            <ResourceDictionary.MergedDictionaries>
                <ResourceDictionary Source="pack://application:,,,/MahApps.Metro;component/Styles/Controls.xaml" />
                <ResourceDictionary Source="pack://application:,,,/MahApps.Metro;component/Styles/Fonts.xaml" />
                <ResourceDictionary Source="pack://application:,,,/MahApps.Metro;component/Styles/Colors.xaml" />
                <ResourceDictionary Source="pack://application:,,,/MahApps.Metro;component/Styles/Accents/Blue.xaml" />
                <ResourceDictionary Source="pack://application:,,,/MahApps.Metro;component/Styles/Accents/BaseLight.xaml" />
                <ResourceDictionary Source="pack://application:,,,/GrimshawRibbon;component/Revit/Wpf/Style/GrimshawTheme.xaml"/>
            </ResourceDictionary.MergedDictionaries>
        </ResourceDictionary>
    </UserControl.Resources>
    <Grid>
        <ex:DataGridEx x:Name="dgViews" 
                               Style="{StaticResource AzureDataGrid}" 
                               Margin="10" 
                               AutoGenerateColumns="False" 
                               ItemsSource="{Binding Views, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" 
                               CanUserAddRows="False" 
                               IsReadOnly="False" 
                               SelectionMode="Extended" 
                               SelectionUnit="FullRow" 
                               SelectedItemsList="{Binding SelectedViews, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}">
            <i:Interaction.Triggers>
                <i:EventTrigger EventName="CellEditEnding">
                    <cmd:EventToCommand PassEventArgsToCommand="True" Command="{Binding CellEditEndingCommand}"/>
                </i:EventTrigger>
            </i:Interaction.Triggers>
            <DataGrid.Columns>
                <DataGridTextColumn Header="Name" Binding="{Binding Name, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" Width="*"/>
                <DataGridTextColumn Header="ViewType" Binding="{Binding ViewType}" Width="100" IsReadOnly="True"/>
                <DataGridTextColumn Header="ViewGroup" Binding="{Binding ViewGroup, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" Width="120" IsReadOnly="False"/>
                <DataGridTextColumn Header="ViewSubGroup" Binding="{Binding ViewSubGroup, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" Width="120" IsReadOnly="False"/>
                <DataGridCheckBoxColumn ElementStyle="{DynamicResource MetroDataGridCheckBox}" 
                                        EditingElementStyle="{DynamicResource MetroDataGridCheckBox}" 
                                        Header="OnSheet" 
                                        Binding="{Binding OnSheet, Mode=TwoWay}" 
                                        IsReadOnly="True" 
                                        Width="80">
                </DataGridCheckBoxColumn>
                <DataGridComboBoxColumn Header="ViewTemplate" Width="150" SelectedItemBinding="{Binding WhatDoISetThisTo?}">
                    <DataGridComboBoxColumn.ElementStyle>
                        <Style TargetType="ComboBox">
                            <Setter Property="ItemsSource" Value="{Binding ViewTemplates}"/>
                            <Setter Property="IsReadOnly" Value="True"/>
                        </Style>
                    </DataGridComboBoxColumn.ElementStyle>
                    <DataGridComboBoxColumn.EditingElementStyle>
                        <Style TargetType="ComboBox">
                            <Setter Property="ItemsSource" Value="{Binding ViewTemplates}"/>
                        </Style>
                    </DataGridComboBoxColumn.EditingElementStyle>
                </DataGridComboBoxColumn>
            </DataGrid.Columns>
        </ex:DataGridEx>
    </Grid>
</UserControl>

View 模型:

public class ViewManagerViewModel : ViewModelBaseEx
    {
        public ViewManagerModel Model;
        public ObservableCollection<ViewWrapper> Views { get; private set; }
        public ObservableCollection<ViewWrapper> ViewTemplates { get; private set; }
        public IList SelectedViews { get; set; }
        public RelayCommand<DataGridCellEditEndingEventArgs> CellEditEndingCommand { get; set; }

        public ViewManagerViewModel(Document doc)
        {
            Model = new ViewManagerModel(doc);
            Views = Model.CollectViews();
            ViewTemplates = Model.CollectViewTemplates();
            CellEditEndingCommand = new RelayCommand<DataGridCellEditEndingEventArgs>(args => OnCellEditEnding(args));
        }

        /// <summary>
        /// Logic for handling cell editing events.
        /// </summary>
        /// <param name="e">DataGrid Row object.</param>
        private void OnCellEditEnding(DataGridCellEditEndingEventArgs e)
        {
            var wrapper = e.Row.Item as ViewWrapper;
            switch (e.Column.SortMemberPath)
            {
                case "Name":
                    Model.ChangeName(wrapper);
                    break;
                case "ViewGroup":
                    Model.SetParameter(wrapper, "View Group", wrapper.ViewGroup);
                    break;
                case "ViewSubGroup":
                    Model.SetParameter(wrapper, "View Sub Group", wrapper.ViewSubGroup);
                    break;
                default:
                    break;
            }
        }

        public override void Apply()
        {
            var vw = new List<ViewWrapper>();
            foreach (ViewWrapper v in SelectedViews)
            {
                vw.Add(v);
            }

            Model.Delete(vw);

            // update collection so that rows get deleted in datagrid
            foreach (ViewWrapper i in vw)
            {
                Views.Remove(i);
            }
        }
    }

ViewWrapper 类:

    public abstract class ElementWrapper : ObservableObject
    {
        public virtual object Self { get; set; }
        public virtual ElementId ID { get; set; }
        public virtual string Name { get; set; }
    }



    public class ViewWrapper : ElementWrapper
    {
        public string ViewType { get; set; }
        public bool IsSelected { get; set; }
        public bool OnSheet { get; set; }
        public string ViewGroup { get; set; }
        public string ViewSubGroup { get; set; }
        public ViewWrapper ViewTemplate { get; set; }

    }

Answer 1

SelectedItemBinding属性应该绑定(bind)到 ViewTemplate ViewWrapper 的属性(property)表示当前行的对象。

自从ViewTemplates集合在 View 模型中定义，您应该使用 RelativeSource binding 能够绑定(bind)到它。

试试这个:

<DataGridComboBoxColumn Header="ViewTemplate" Width="150" SelectedItemBinding="{Binding ViewTemplate}">
    <DataGridComboBoxColumn.ElementStyle>
        <Style TargetType="ComboBox">
            <Setter Property="ItemsSource" Value="{Binding DataContext.ViewTemplates, RelativeSource={RelativeSource AncestorType=DataGrid}}"/>
            <Setter Property="IsReadOnly" Value="True"/>
        </Style>
    </DataGridComboBoxColumn.ElementStyle>
    <DataGridComboBoxColumn.EditingElementStyle>
        <Style TargetType="ComboBox">
            <Setter Property="ItemsSource" Value="{Binding DataContext.ViewTemplates, RelativeSource={RelativeSource AncestorType=DataGrid}}"/>
        </Style>
    </DataGridComboBoxColumn.EditingElementStyle>
</DataGridComboBoxColumn>