Datagrid 单元格内容在 WPF 中不可见

Datagrid Cell content is not visible in WPF

我有一个包含 8 列的数据网格,连接前 2 列值并将其绑定到每一行的第 7 列。[绑定过程在第 6 列的日历关闭事件中完成]在绑定第 7 列之后列值 绑定值在特定行的第 7 个单元格中不可见,但如果我双击特定单元格,则数据可见...我不知道出了什么问题...

public class pojo
{
    public string Prefix { get; set; }
    public int Year { get; set; }
    public int QuarterNo { get; set; }
    public int SerialNo { get; set; }
    public string From { get; set; }
    public string To { get; set; }
    public string PeriodName { get; set; }
}

ObservableCollection<pojo> models = new ObservableCollection<pojo>();

private void Period_Name(object sender, RoutedEventArgs e)
{
    var rowdata = calendarmstrDG.SelectedItem as pojo;
    var prefix = rowdata.Prefix;
    int year = rowdata.Year;
    int year_twodigits = year % 100;
    string sth = prefix + '-' + year_twodigits.ToString();
    pojo obj = (pojo)calendarmstrDG.SelectedItem;
    obj.PeriodName = sth;
}

Xaml 第 8 列的代码

 <DataGridTextColumn Binding="{Binding Path=PeriodName}"  Width="85" IsReadOnly="True" Header="Period Name"/>

Class 应该是这样的(其他字段省略):

public class pojo : INotifyPropertyChanged
{

    private string _prefix;
    private int _year;

    public string Prefix
    {
        get => _prefix;
        set
        {
            if (_prefix == value) return;
            _prefix = value;
            OnPropertyChanged(nameof(PeriodName));
        }
    }
    public int Year
    {
        get => _year;
        set
        {
            if (_year == value) return;
            _year = value;
            OnPropertyChanged(nameof(PeriodName));
        }
    }
    public string PeriodName => _prefix + '-' + (_year % 100).ToString(); 

    public event PropertyChangedEventHandler PropertyChanged;
    void OnPropertyChanged(string prop)
    {
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(prop));
    }
}