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DataGridView bound to BindingList does not refresh when value changed

开发者 https://www.devze.com 2023-01-09 04:15 出处:网络
I have a DataGridView bound to a BindingList (C# Windows Forms). If I change one of the values in an item in the list 开发者_开发百科it does not immediately show up in the grid. If I click on the chan

I have a DataGridView bound to a BindingList (C# Windows Forms). If I change one of the values in an item in the list 开发者_开发百科it does not immediately show up in the grid. If I click on the changed cell, or minimize then maximize the window it updates properly, but I need it to happen automatically.

I had the same problem earlier, but in that situation I had to change the cell's background colour at the same time that the value changed. This caused the cell to refresh correctly.

The only way I can get it to work is...

dataGridView.DataSource = null;  
dataGridView.DataSource = myBindingList

...but I'd really like to avoid this as it makes the scrollbar pop back to the top, and means that I'd have to set my cell background colours again. Surely there's a better way. I've tried Refresh (as well as refreshing the parent), Update, and Invalidate, but they're not doing what I need.

I've seen this problem mentioned on a few message boards, but haven't seen a working answer to it yet.


ListChanged notifications for item value changes are only raised if the list item type implements the INotifyPropertyChanged interface.

Taken from: http://msdn.microsoft.com/en-us/library/ms132742.aspx

So my first question would be: Implements your item the INotifyPropertyChanged properly?


Just call myBindingList.ResetBindings() whenever your data changes!


Your datasource should implement INotifyPropertyChanged for any change in the BindingList to be reflected in the datagridview.

class Books : INotifyPropertyChanged
{
   private int m_id;
   private string m_author;
   private string m_title;

   public int ID { get { return m_id; } set { m_id = value; NotifyPropertyChanged("ID"); } }
   public string Author { get { return m_author; } set { m_author = value; NotifyPropertyChanged("Author"); } }
   public string Title { get { return m_title; } set { m_title = value; NotifyPropertyChanged("Title"); } }


   public event PropertyChangedEventHandler PropertyChanged;

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

BindingList<Books> books= new BindingList<Books>();

datagridView.DataSource = books;


It sounds as your Change Object notification is not triggered / handled correctly. I personally always use the BindingSource object when binding to a dataGridView.

I would check out the DataGridView FAQ and the DataBinding FAQ and search for object change notification.

If you are using ADO.Net, don't forget the call the .Validate() and .EndEdit() methods.


    private void refreshDataGrid()
    {
        dataGridView1.DataSource = typeof(List<>);
        dataGridView1.DataSource = myBindingList;
        dataGridView1.AutoResizeColumns();
        dataGridView1.Refresh();
    }

Then, just call for the refreshDataGrid Method anytime a change occurs to your list.

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