DataGridRowEditEndingEventArgs 的 row.item 返回 null

Question

我刚刚创建了一个新的 WPF MVVMLight 项目，很简单:

MainWindow.xaml

<Window x:Class="DG.MainWindow"
        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:i="http://schemas.microsoft.com/expression/2010/interactivity"
        xmlns:command="http://www.galasoft.ch/mvvmlight"            
        DataContext="{Binding Main, Source={StaticResource Locator}}">

    <i:Interaction.Triggers>
        <i:EventTrigger EventName="Loaded">
            <command:EventToCommand Command="{Binding Loaded}"/>
        </i:EventTrigger>
    </i:Interaction.Triggers>

    <Grid>    
        <DataGrid ItemsSource="{Binding Personnes, UpdateSourceTrigger=PropertyChanged}" AutoGenerateColumns="True"                      CanUserAddRows="True" CanUserDeleteRows="True">
            <i:Interaction.Triggers>
                <i:EventTrigger EventName="RowEditEnding">
                    <command:EventToCommand Command="{Binding RowEditEnding}" PassEventArgsToCommand="True"/>
                </i:EventTrigger>
            </i:Interaction.Triggers>    
        </DataGrid>    
    </Grid>
</Window>

主要（ViewModel）

public class MainViewModel : ViewModelBase
    {
        public RelayCommand Loaded
        {
            get
            {
                return new RelayCommand(() =>
                {
                    Personnes = new ObservableCollection<Personne>();
                    Personnes.Add(new Personne("Daoudi", "25"));
                    Personnes.Add(new Personne("Aymen", "26"));
                });
            }
        }

        public RelayCommand<DataGridRowEditEndingEventArgs> RowEditEnding
        {
            get
            {
                return new RelayCommand<DataGridRowEditEndingEventArgs>((e) =>
                {
                    int i = 5;
                });
            }
        }

        public ObservableCollection<Personne> Personnes
        {
            get { return _personnes; }
            set
            {
                _personnes = value;
                RaisePropertyChanged("Personnes");
            }
        }

        private ObservableCollection<Personne> _personnes; 
        public MainViewModel()
        {
           
        }            
    }

人class

public class Personne
    {
        public string Name { get; set; }
        public string Age { get; set; }

        public Personne ()
        {
            
        }

        public Personne(string name, string age)
        {
            Name = name;
            Age = age;
        }
    }

尝试添加新行时，在 RowEditEnding 中，e.Row.item 显示 null :

为什么会这样？

注意：我在 Peronnes 列表中尝试了 ObservableColletion 和 BindingList，在 DataGrid 的 ItemsSource 的绑定中尝试了 PropertyChanged 和 LostFocus 中的 UpdateSourceTrigger，总是结果相同！

Answer 1

看来您需要手动指定列并精确 UpdateSourceTrigger，这应该可以正常工作！

 <DataGrid HorizontalAlignment="Left" Margin="0,10,0,0" AutoGenerateColumns="False" ItemsSource="{Binding Personnes}" VerticalAlignment="Top" Height="148" Width="282"
                      CanUserAddRows="True" CanUserDeleteRows="True">
                <DataGrid.Columns>
                    <DataGridTextColumn Header="Name" Binding="{Binding Name, UpdateSourceTrigger=LostFocus}"/>
                    <DataGridTextColumn Header="Age" Binding="{Binding Age, UpdateSourceTrigger=LostFocus}"/>
                </DataGrid.Columns>
...

因此设置 AutoGenerateColumns="False" 无助于实现结果！

DataGridRowEditEndingEventArgs 的 row.item 返回 null

DataGridRowEditEndingEventArgs 's row.item returning null

c#

data-binding

wpf

xaml

wpfdatagrid