更新數據源時刷新Datagrid

Question

我有一個數據網格，顯示一個綁定到DataSource的表，該DataSource不斷更改時間約束。 如何在更新DataSource值時刷新數據網格的內容。

PS：我的DataSource表中的值由監控系統更新。 其表值定期更新。

我應該在EF中添加我的Observable Collection？

    private IQueryable<MyTable> GetMyTablesQuery(TestDBEntities1 testDBEntities1 )
    {
         // definition of a Query to retrieve the info from my DB
        System.Data.Objects.ObjectQuery<EF_demo1.MyTable> myTablesQuery = testDBEntities1.MyTables;
         // Returns an ObjectQuery.
        return myTablesQuery ;
    }

    private void Window_Loaded(object sender, RoutedEventArgs e)
    {
         // A New entity container is created that uses the object context
        var testDBEntities1 = new EF_demo1.HMDBEntities1();
         // Load data into MyTables. 
        var myTablesViewSource= ((System.Windows.Data.CollectionViewSource)(this.FindResource("myTablesViewSource")));
         // the query which is defined above is executed here. It grabs all the information from the entity container
        IQueryable<EF_demo1.MyTable> myTablesQuery = this.GetMyTablesQuery(testDBEntities1 );
         //The query result is binded to the source of the myTablesViewSource, which inturn binds back to the list.
        myTablesViewSource.Source = myTablesQuery .ToList();
    }

Answer 1

一種可能的方法是使用ObservableCollection：

BoundCollection = new ObservableCollection<MyEntityType>(entities);

BoundCollection中使用BoundCollection位置。 然后，每當更新值時，您將清除集合並重新添加它們：

BoundCollection.Clear();
foreach(var e in entities)
{
    BoundCollection.Add(e);
}

這是另一個使用INotifyPropertyChanged並每次重新綁定集合的選項。 但是，使用ObservableCollection是首選方法，因為它旨在添加和刪除將自動更新UI的項目。

public class MyModel : INotifyPropertyChanged
{
  public IList<MyEntity> BoundCollection {get; private set;}

  public MyModel()
  {
    UpdateBinding();
  }

  private void UpdateBinding()
  {
    // get entities
    BoundCollection = new List<MyEntity>(entities);
    // this notifies the bound grid that the binding has changed
    // and should refresh the data
    NotifyPropertyChanged("UpdateBinding");
  }

  public event PropertyChangedEventHandler PropertyChanged;

  private void NotifyPropertyChanged( string propertyName = "")
  {
    if (PropertyChanged != null)
    {
      PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
    }
  }
}