Sorting a datagrid on a hidden column

  • Thread starter Thread starter Kirti
  • Start date Start date
K

Kirti

Hi,
I would like to sort a datagrid not on the column that is displayed,
but on another hidden column. I have AllowSorting = true.


This is what I am doing in load.
//tmpMembList is my DataSet that has the required results. The column
that is displayed is AccountNumber but I would like to sort on
'SortColumn' which is a hidden column in the datagrid. This seems to
work fine and when I get the form loaded, i can see the grid sorted.

Load()
{
// Get the DataTable associated with this datagrid.
dataTable = tmpMembList.Tables[0];

// Get the DataView associated with the DataTable.
dataView = dataTable.DefaultView;

dataView.ApplyDefaultSort = false;

dataView.Sort = "[SortColumn]";

dgMemberList.DataSource = dataTable;

if (dgMemberList.VisibleRowCount >0)
dgMemberList.Select(0);
}

Now I want to sort when the user clicks on the column header.
This is what I have been trying. I am capturing the mouse down event
and then getting the dataview and changing the sort again


private void dgMemberList_MouseDown(object o, MouseEventArgs mea)
{
string columnName;
DataGrid.HitTestInfo hitTest;

// Use only left mouse button clicks.
if (mea.Button == MouseButtons.Left)
{
// Perform a hit test to determine where the mousedown event
occured.
hitTest = dgMemberList.HitTest(mea.X, mea.Y);

// If the mousedown event occured on a column header,
// then perform the sorting operation.

if (hitTest.Type == DataGrid.HitTestType.ColumnHeader)
{
// Reset mouse button state.
buttonPress = true;

// Get the DataTable associated with this datagrid.
dataTable = (DataTable)dgMemberList.DataSource;

// Get the DataView associated with the DataTable.
dataView = dataTable.DefaultView;
dataView.ApplyDefaultSort = false;

// Get the name of the column that was clicked.
columnName = dataTable.Columns[hitTest.Column].ColumnName;

// If the sort property of the DataView is already the current
// column name, sort that column in descending order.
// Otherwise, sort on the column name.
if (columnName == "AccountNumber")
{
if (dataView.Sort == "[SortColumn]")
dataView.Sort = "[SortColumn] DESC";
else
dataView.Sort = "[SortColumn]";
}
}
}
}

I can see that it is sorting in the right way when I do the mouse
down. But when I leave the mouse (mouse up) it again sorts it on the
accountnumber.

if i put this code in Mouse up, it does not work at all.

Please HELP.

Thanks,
Kirti
 
Kirti said:
Hi,
I would like to sort a datagrid not on the column that is displayed,
but on another hidden column. I have AllowSorting = true.
Click to expand...
I can see that it is sorting in the right way when I do the mouse
down. But when I leave the mouse (mouse up) it again sorts it on the
accountnumber.
Click to expand...

I'm just guessing here, but I think what's happening is that your
sorting routine is working on MouseDown, but then the DataGrid's built-in
sorting is kicking in on MouseUp. Since you're handling sorting manually,
try changing AllowSorting to false and see if that solves the problem.

Jeremy
 
if you do the sorting inside the eventhandler of mousedown it is likely the
sorting is disposed when the eventhandler procedure ends.
 
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