在C＃WPF中將嵌套對象綁定到DataGrid

Question

我正在嘗試將DataGrid中顯示的數據綁定到另一個對象（WhisperReader）內部的對象（WhisperModel）的動態列表。 DataGrid僅顯示標題，但不顯示任何值。 當列表“耳語”更改時，如何使DataGrid動態更新自身？

主窗口XAML：

<DataGrid x:Name="whisperDataGrid" Margin="10,69,10,10" IsReadOnly="True" ItemsSource="{Binding}"/>

主窗口C＃

public partial class MainWindow : Window
{
    private WhisperReader wr;
    public MainWindow()
    {
        InitializeComponent();
        wr = new WhisperReader();
        whisperDataGrid.DataContext = wr.whispers;
    }

WhisperReader：

class WhisperReader
{
    public ObservableCollection<WhisperModel> whispers { get; private set; }

    public WhisperReader()
    {
        whispers = new ObservableCollection<WhisperModel>();
    }

WhisperModel：

class WhisperModel
{
    public DateTime sentTime { get; set; }
    public string sender { get; set; }
    public string message { get; set; }
}

Answer 1

我認為您的問題是它不知道何時更新自身，因為：

1. 您已將耳語列出了數據上下文。
2. 您要綁定的屬性不使用INotifyPropertyChanged。
3. WhisperReader和WhisperModel不公開

所有綁定必須是公共的，必須是屬性，並且必須調用PropertyChanged方法。 PropertyChanged函數觸發綁定更新。

嘗試這個...

public partial class MainWindow : Window
{
    private WhisperReader wr;
    public MainWindow()
    {
        InitializeComponent();
        wr = new WhisperReader();
        whisperDataGrid.DataContext = wr;
    }

public class WhisperReader : INotifyPropertyChanged
{
    ObservableCollection<WhisperModel> _whispers;
    public ObservableCollection<WhisperModel> whispers 
    { 
      get { return _whispers; } 
      private set 
      {
         _whispers = value;
         NotifyPropertyChanged(); 
      }
    }

    public WhisperReader()
    {
        whispers = new ObservableCollection<WhisperModel>();
    }

    public event PropertyChangedEventHandler PropertyChanged;
    private void NotifyPropertyChanged([CallerMemberName] String propertyName = "")
    {
        if (PropertyChanged != null)
        {
            PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
        }
    }


public class WhisperModel : INotifyPropertyChanged
{
    public DateTime sentTime { get; set; }

    private string _sender;
    public string sender 
    { 
        get { return _sender; } 
        set { _sender = value; NotifyPropertyChanged();
    }

    private string _message;
    public string message 
    { 
        get { return _message; } 
        set { _message = value; NotifyPropertyChanged();
    }

    public event PropertyChangedEventHandler PropertyChanged;
    private void NotifyPropertyChanged([CallerMemberName] String propertyName = "")
    {
        if (PropertyChanged != null)
        {
            PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
        }
    }
}

<DataGrid x:Name="whisperDataGrid" Margin="10,69,10,10" IsReadOnly="True" AutoGenerateColumns="True" ItemsSource="{Binding whispers}"/>