WPF中如何为DataGrid选中项添加面试日期列并优化显示

1. 修复类型错误并完善addInterviewDT方法 #

首先你代码里的ShClient是错误类型，应该用ShortlistedClient。另外需要先给TextBox命名并绑定按钮点击事件：

修改XAML元素 #

给TextBox添加名称，同时给按钮绑定Click事件：

<Button Content="Add Interview DT" Width="128" FontWeight="Bold" Height="28" Click="addInterviewDT"/>
<TextBox x:Name="txtInterviewDT" TextWrapping="Wrap" Width="120" Height="46"/>

完善后台方法 #

// 填充日期时间列的方法
private void addInterviewDT(object sender, RoutedEventArgs e)
{
    var selectedClient = dgr.SelectedItem as ShortlistedClient;
   
    // 验证选中项+日期格式合法性
    if (selectedClient != null && DateTime.TryParse(txtInterviewDT.Text, out DateTime interviewDT))
    {
        selectedClient.DT = interviewDT;
        // 如果后续实现了属性通知，这里可以省略刷新
        dgr.Items.Refresh();
    }
}

2. 让“Interview Date and time”列显示为空而非默认值 #

默认DateTime是值类型，初始值为DateTime.MinValue，改成可空类型就能让未设置的单元格显示为空：

修改ShortlistedClient类 #

把DT改成可空DateTime?，同时实现INotifyPropertyChanged接口确保UI自动更新：

public class ShortlistedClient : Client, INotifyPropertyChanged
{
    private DateTime? _dt;
    public DateTime? DT 
    { 
        get => _dt; 
        set 
        {
            _dt = value;
            OnPropertyChanged(nameof(DT));
        }
    }
    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 = null; // 初始化为null，对应空显示
        InterestedinVac = false;
    }

    // 属性变更通知，用于WPF UI自动更新
    public event PropertyChangedEventHandler PropertyChanged;
    protected void OnPropertyChanged(string propertyName)
    {
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
    }
}

修改XAML日期列绑定 #

设置日期显示格式，同时指定空值显示内容：

<DataGridTextColumn Header="Interview Date and time" 
                    Binding="{Binding DT, StringFormat='yyyy/MM/dd HH:mm', TargetNullValue=''}"/>

3. 优化数据源更新（可选） #

用ObservableCollection代替List，删除操作后UI会自动更新，无需手动重置数据源：

// 替换List为ObservableCollection
ObservableCollection<ShortlistedClient> shlclients = new ObservableCollection<ShortlistedClient>();

public Shortlist()
{
    InitializeComponent();
    DataContext = shlclients;
    shlclients.Add(new ShortlistedClient("Rich", "07515118265", "rich@gmail.com", "Glasgow", "Office", "MSc", "more than 3 years", "Yes", "No"));
    shlclients.Add(new ShortlistedClient("Steve", "07515118265", "steve@gmail.com", "Glasgow", "Construction", "High School", "more than 3 years", "Yes", "No"));
    shlclients.Add(new ShortlistedClient("Maria", "07485999005", "mb@gmail.com", "Edinburgh", "Office", "MSc", "more than 3 years", "No", "No"));
}

// 简化删除方法
private void RemoveShClient(object sender, RoutedEventArgs e)
{
    if (dgr.SelectedItem is ShortlistedClient selectedClient)
    {
        shlclients.Remove(selectedClient);
    }
    else
    {
        // 用WPF自带消息框替代WinForms的
        System.Windows.MessageBox.Show("No Clients Found");
    }
}

内容的提问来源于stack exchange，提问作者Bluetail