c# - MVVM 中的 Datagrid 绑定(bind)和编辑

Question

在使用了多年的代码后，我刚刚尝试从 MVVM 开始。我试图让 ThisClaimValue 在 PercentageComplete 更改时更新。 ThisClaimValue 旨在显示 ContractAmt 的百分比，基于 PercentageComplete。无论是在人们投入值(value)的时候，还是在他们离开牢房的时候。我正在尝试使用零代码来执行此操作，因此没有内置事件。

我将 EF Database First 用于描述、ContractAmt 和 BillCurrentAmt。 PercentageComplete 和 ThisClaimValue 作为 EF 创建的类的部分类位于单独的解决方案中。

看法:

   <DataGrid Margin="10,10,10,0" RowDetailsVisibilityMode="VisibleWhenSelected" EnableRowVirtualization="True" AutoGenerateColumns="False" ItemsSource="{Binding JCCISelectedList, UpdateSourceTrigger=PropertyChanged}" SelectedValue="{Binding JCCI}" Grid.Row="3">
        <DataGrid.Columns>
            <DataGridTextColumn   Binding="{Binding Description}" Header="Description" Width="Auto" IsReadOnly="True"/>
            <DataGridTextColumn  Binding="{Binding ContractAmt}" Header="Value" Width="Auto" IsReadOnly="True"/>
            <DataGridTextColumn  Binding="{Binding PercentageComplete, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" Header="% Complete" Width="Auto"/>
            <DataGridTextColumn  Binding="{Binding BillCurrentAmt, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" Header="$ Complete" Width="Auto"/>
            <DataGridTextColumn  Binding="{Binding ThisClaimValue}" Header="This Claim Value" Width="Auto" IsReadOnly="True"/>
        </DataGrid.Columns>
    </DataGrid>

View 模型:

  public class JBProgressBillItemsViewModel : INotifyPropertyChanged, IPageViewModel
    {
        public AcceptCommand AcceptEvent { get; set; }
        public BackCommand BackEvent { get; set; }
        public string Name => "JBProgressBillItems";

        public JBProgressBillItemsViewModel()
        {
            HQCOList = Facade.GetVistaHQCO();
            AcceptEvent = new AcceptCommand(this);
            BackEvent = new BackCommand(this);
        }
        private bHQCO _hqco;
        private bJCCM _jccm;
        private bJCCI _jcciSection;
        private bJCCI _jcci;

        public ObservableCollection<bHQCO> HQCOList { get; }
        public ObservableCollection<bJCCM> JCCMList { get; private set; }
        public ObservableCollection<bJCCI> JCCISectionList { get; private set; }
        public ObservableCollection<bJCCI> JCCIList { get; private set; }
        public ObservableCollection<bJCCI> JCCISelectedList { get; private set; }

        public bHQCO HQCO
        {
            get { return _hqco; }
            set
            {
                _hqco = value;
                JCCMList = Facade.GetVistaActiveProjects(_hqco.HQCo);
                RaisePropertyChanged(nameof(HQCO));
                RaisePropertyChanged(nameof(JCCMList));
            }
        }

        public bJCCM JCCM
        {
            get { return _jccm; }
            set
            {
                _jccm = value;
                JCCIList = Facade.GetVistaContractItems(_hqco.HQCo, _jccm.Contract);
                JCCISectionList =
                    new ObservableCollection<bJCCI>(JCCIList.Where(x => x.SICode == "H" || x.SICode == "SH"));
                RaisePropertyChanged(nameof(JCCM));
                RaisePropertyChanged(nameof(JCCISectionList));
            }
        }

        public bJCCI JCCISection
        {
            get { return _jcciSection; }
            set
            {
                _jcciSection = value;
                try
                {
                    JCCISelectedList = new ObservableCollection<bJCCI>(JCCIList.Where(x => _jcciSection.BillGroup == x.BillGroup && string.IsNullOrWhiteSpace(x.SICode)));
                }
                catch (ArgumentNullException)
                {
                }
                RaisePropertyChanged(nameof(JCCISection));
                RaisePropertyChanged(nameof(JCCISelectedList));
            }
        }

        public bJCCI JCCI
        {
            get { return _jcci; }
            set
            {
                _jcci = value;
                _jcci.ThisClaimValue = value.PercentageComplete * value.ContractAmt / 100;
                RaisePropertyChanged(nameof(JCCI));
                RaisePropertyChanged(nameof(JCCISelectedList));
            }
        }

        public event PropertyChangedEventHandler PropertyChanged;
        private void RaisePropertyChanged(string propertyName)
        {
            PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
        }

        public string Error => null;

    }

编辑:在上面添加了全 View 模型代码。

Answer 1

要使其正常工作，请确保 JCCISelectedList指定为 ObservableCollection这将解决您的问题。
否则，您需要为每个引发 Property changed 事件Description ContractAmt .... 每个元素单独作为 raiseproperty changed 事件不会为元素更改生成任何事件作为 JCCISelectedList 的属性当元素更改其正在更改的数据上下文时保持不变。