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我有一个方法，用来解析和获取用户在WPF中的textBox中键入的时间，然后它应该将一个字符串（如“12：05”）作为值添加到我选择的项目中。

private void addInterviewTime(object sender, RoutedEventArgs e)
       {
           ShortlistedClient sc = dgr.SelectedItem as ShortlistedClient;

           if (sc != null && DateTime.TryParseExact(textBox.Text, "HH: mm", out TimeOnly result))
           {
               sc.DT = result;
           }

       }

它给出以下错误：

// and for   sc.DT = result;

Error   CS0029  Cannot implicitly convert type 'System.TimeOnly' to 'System.DateTime?'

我也试过

if (sc != null && TimeOnly.TryParseExact(textBox.Text, "HH: mm", out TimeOnly result))
            {
                sc.DT = result;
            }

# with

    public class ShortlistedClient : Client, INotifyPropertyChanged
    {
        private TimeOnly? _dt;

        public TimeOnly?  DT
        {
            get { return _dt; }
            set { _dt = value; NotifyPropertyChanged(); }
        }

        public bool InterestedinVac { get; private set; }
      

        public List<ShortlistedClient> clients { get; set; } = new List<ShortlistedClient>();
        public ShortlistedClient(string n, string p, string e, string l, string wt, string q, string we, string dl, string cc) : base(n, p, e, l, wt, q, we, dl, cc)
        {
            DT = new TimeOnly(); 
            InterestedinVac = true; 
        }

而且它仍然

Error   CS0029  Cannot implicitly convert type 'System.TimeOnly' to 'System.DateTime?'

之前，我在ShortlistedClient类中设置了如下DT属性：

public class ShortlistedClient : Client, INotifyPropertyChanged
    {
        private DateTime? _dt;

        public DateTime?  DT
        {
            get { return _dt; }
            set { _dt = value; NotifyPropertyChanged(); }
        }

        public bool InterestedinVac { get; private set; }
      

        public List<ShortlistedClient> clients { get; set; } = new List<ShortlistedClient>();
        public ShortlistedClient(string n, string p, string e, string l, string wt, string q, string we, string dl, string cc) : base(n, p, e, l, wt, q, we, dl, cc)
        {
            DT = new DateTime(); 
            InterestedinVac = true; 
        }

我的标记代码：

<Window x:Class="WpfApp_Employment_Help.Shortlist"
        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:WpfApp_Employment_Help"
        mc:Ignorable="d"
        Title="Shortlist" Height="450" Width="800">
    <StackPanel Margin="0,0,0,73">
        <DataGrid x:Name="dgr" AutoGenerateColumns="False" ItemsSource="{Binding}" IsSynchronizedWithCurrentItem="True" CanUserAddRows="False" Height="154" Width="793">
            <DataGrid.Columns>
                <DataGridTextColumn Header="Name" Binding="{Binding Name}" />
                <DataGridTextColumn Header="Email" Binding="{Binding Email}" />
                <DataGridTextColumn Header="Phone" Binding="{Binding Phone}"/>
                <DataGridTextColumn Header="Location" Binding="{Binding Location}"/>
                <DataGridTextColumn Header="Worktype" Binding="{Binding Worktype}"/>
                <DataGridTextColumn Header="Qualification" Binding="{Binding Qualification}"/>
                <DataGridTextColumn Header="Workexp" Binding="{Binding Worktype}"/>
                <DataGridTextColumn Header="Driving licence" Binding="{Binding Drlicence}"/>
                <DataGridTextColumn Header="Criminal conviction" Binding="{Binding Crconviction}"/>
                <DataGridTextColumn Header="Interested in vacancy" Binding="{Binding InterestedinVac}"/>
                <DataGridTextColumn Header="Interview Date" Binding="{Binding DT}"/>
            </DataGrid.Columns>
        </DataGrid>
        <Button Content="Add Interview DT" Width="128" FontWeight="Bold" Height="28" Click="addInterviewDT"/>
        <DatePicker x:Name="DatePick" Height="52" Width="200"/>
        <TextBox x:Name="textBox" TextWrapping="Wrap" Width="197" Height="45" Text="Enter time&#xD;&#xA;"/>
        <Button x:Name="BtnRemoveShlClient" Content="Remove Shortlisted Client" FontWeight="Bold" Height="33" Width="220" Click="RemoveShClient"/>
    </StackPanel>
</Window>

我怎么能只有时间来修复这个错误呢？