我在绑定到ViewModel（VM）的WPF UserControl中有一个只读数据网格，并且有一个SelectedItem绑定到VM的属性。还有两个文本框，一个绑定到SelectedItem属性，另一个绑定到VM属性。

<UserControl
    x:Class="PhoneAssistant.WPF.Features.ServiceRequests.ServiceRequestsMainView"
    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:local="clr-namespace:PhoneAssistant.WPF.Features.ServiceRequests"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    d:DataContext="{d:DesignInstance Type=local:ServiceRequestsMainViewModel}"
    d:DesignHeight="450"
    d:DesignWidth="800"
    mc:Ignorable="d">
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto" />
            <RowDefinition Height="*" />
        </Grid.RowDefinitions>
        <Grid
            Grid.Row="0"
            Margin="16,20,0,15"
            d:Background="LightCoral">
            <Grid.ColumnDefinitions>
                <ColumnDefinition Width="auto" />
                <ColumnDefinition Width="auto" />
            </Grid.ColumnDefinitions>
            <TextBox
                Grid.Column="0" Margin="0,0,5,0"
                Text="{Binding SelectedSR.BoundToSelected}" />
            <TextBox
                Grid.Column="1" Margin="0,0,5,0"
                Text="{Binding VmProperty}" />
        </Grid>
        <DataGrid
            Grid.Row="1" AutoGenerateColumns="False"
            IsReadOnly="true"
            ItemsSource="{Binding ServiceRequests}"
            SelectedItem="{Binding SelectedSR}"
            SelectionMode="Single"SelectionUnit="FullRow">
            <DataGrid.Columns>
                <DataGridTextColumn
                    Width="auto"
                    Binding="{Binding BoundToSelected}"
                    Header="BoundToSelected" />
                <DataGridTextColumn
                    Width="auto"
                    Binding="{Binding BoundToVMProperty}"
                    Header="BoundToVMProperty" />
            </DataGrid.Columns>
        </DataGrid>
    </Grid>
</UserControl>

对绑定到SelectedItem属性的文本框所做的更改将反映回DataGrid，但对绑定到VM属性的文本框所做的更改不会反映回DataGrid。

using System.Collections.ObjectModel;

using CommunityToolkit.Mvvm.ComponentModel;

namespace PhoneAssistant.WPF.Features.ServiceRequests;

public sealed partial class ServiceRequestsMainViewModel : ObservableObject, IServiceRequestsMainViewModel
{
    public ObservableCollection<ServiceRequest> ServiceRequests { get; } = new();

    [ObservableProperty]
    private ServiceRequest _selectedSR;

    partial void OnSelectedSRChanged(ServiceRequest value)
    {
        VmProperty = value.BoundToVMProperty;
    }

    [ObservableProperty]
    // Neither of these notifies update the datagrid
    [NotifyPropertyChangedFor(nameof(ServiceRequests))]   
    [NotifyPropertyChangedFor(nameof(SelectedSR))]
    private string _vmProperty;
    
    partial void OnVmPropertyChanged(string value)
    {
        SelectedSR.BoundToVMProperty = value;
    }

    public Task LoadAsync()
    {
        ServiceRequests.Add(new ServiceRequest() { Id = 1, BoundToSelected = "SomeValue1", BoundToVMProperty = "AnotherValee1"});
        ServiceRequests.Add(new ServiceRequest() { Id = 2, BoundToSelected = "SomeValue2", BoundToVMProperty = "AnotherValee2" });
        ServiceRequests.Add(new ServiceRequest() { Id = 3, BoundToSelected = "SomeValue3", BoundToVMProperty = "AnotherValee3" });
        return Task.CompletedTask;
    }
}

public sealed class ServiceRequest
{
    public int Id { get; init; }
    public string BoundToSelected { get; set; }
    public string BoundToVMProperty { get; set; }
}

我如何获得这些更改以更新数据网格？