How to sort DataGridView when bound to a binding source that is linked to an EF4 Entity
c# datagridview entity-framework sorting winforms
Question
I have a DataGridView that is linked to a BindingSource.
My BindingSource is linked to an IQueryable list of entities:
public void BindTo(IQueryable elements)
{
BindingSource source = new BindingSource();
source.DataSource = elements;
bindingNavigator1.BindingSource = source;
dataGridView1.DataSource = source;
}
I am wanting my users to be able to click on the grid headers to sort the data - struggling to get this to work. Is it possible? If so, how do I do it?
Accepted Answer
I recently struggled with this same issue; it seems that the IQueryable interface doesn't provide enough information for the DataViewGrid to know how to sort the data automatically; so you have to either repackage your collection from the Entity source using something it can use or do what I did and handle the sorting functionality manually:
private void myDataGridView_ColumnHeaderMouseClick(object sender, DataGridViewCellMouseEventArgs e)
{
DataGridViewColumn column = myDataGridView.Columns[e.ColumnIndex];
_isSortAscending = (_sortColumn == null || _isSortAscending == false);
string direction = _isSortAscending ? "ASC" : "DESC";
myBindingSource.DataSource = _context.MyEntities.OrderBy(
string.Format("it.{0} {1}", column.DataPropertyName, direction)).ToList();
if (_sortColumn != null) _sortColumn.HeaderCell.SortGlyphDirection = SortOrder.None;
column.HeaderCell.SortGlyphDirection = _isSortAscending ? SortOrder.Ascending : SortOrder.Descending;
_sortColumn = column;
}
I hope that helps.
Popular Answer
This code snippet works very well, and fast enough for most purposes...
int iColNumber = 3; //e.g., sorting on the 3rd column of the DGV
MyBindingSource.DataSource = MyBindingList.OrderByDescending(o => o.GetType().GetProperty(MyDataGridView.Columns[iColNumber].Name).GetValue(o));
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