Expand group(s) from ListChanged event

[Jason Southgate]

Hello,

I''ve been struggling with creating an algorithm for the following problem for a few hours now, I hope you can help.

It appears to be simple. I am listening to the ListChanged event of the DataView providing the data for my GridGrouping control linkMonitorGrid, and if the [Status] field has a certain condition (values 0 or 1), I want to expand the group in which that child resides.

At first I thought about using the NewIndex property and passing this to my own method, CheckForPossibleGridExpands:

private void OnLinkViewChanged ( object sender, ListChangedEventArgs e )
{
// if it''s an addition or an update
if ( e.ListChangedType == ListChangedType.ItemAdded
|| e.ListChangedType == ListChangedType.ItemChanged )
{
CheckForPossibleGridExpands( e.NewIndex );
}
else if ( e.ListChangedType == ListChangedType.Reset )
{
CheckForPossibleGridExpands();
}
}

private void CheckForPossibleGridExpands(int rowIndex)
{
int status = Convert.ToInt16(this.linkMonitorGridView.Table.Rows[rowIndex]["Status"]);
// compare the new status with the one currently stored in the grid
if ( status == 0 || status == 1 )
{
// fetch the primary key MarketID
string marketId = this.linkMonitorGridView.Table.Rows[rowIndex]["MarketID"];

Syncfusion.Grouping.Table table = this.linkMonitorGrid.TableModel.Table;
Syncfusion.Grouping.ElementsInTableCollection elements = table.Elements;
//table.FilteredRecords

RecordFilterDescriptor rfd = new RecordFilterDescriptor("MarketID", new Syncfusion.Grouping.FilterCondition(FilterCompareOperator.Equals, marketId) );
RecordFilterDescriptorCollection rfdc = new RecordFilterDescriptorCollection();
rfdc.Add(rfd);

// expand the grid group
table.ExpandAllGroups();
}
}

and overloading this method with one which iterates through the linkMonitorGridView.Table.Rows when I recieve a ListChangedType.Reset, but i am not thinking that I should perhaps apply a filter to the this.linkMonitorGrid.TableModel.Table? Is that the right approach??

Also am I correct that linkMonitorGrid.TableModel.Table.ExpandAllGroups() will expand the group one I have located the record in the table, or do I need to be traversing some actual grid properties to correctly use ExpandAllGroups()???

Thanks in advance for your assistance.

Jason Southgate.

[Administrator]

Hi Jason,

applying a filter is not a good approach. It will modify the collection of available records for the table (Table.FilteredRecords).

But you can use the UnsortedRecords collection and look up a record based on its source index. See below.

private void OnLinkViewChanged ( object sender, ListChangedEventArgs e )
{
// if it''''s an addition or an update
if ( e.ListChangedType == ListChangedType.ItemAdded
|| e.ListChangedType == ListChangedType.ItemChanged )
{
Record r = this.linkMonitorGrid.Table.UnsortedRecords[e.NewIndex];
// and then either
r.ParentTable.ShowRecord(r, true);
// or
r.ParentGroup.IsExpanded = true;
}
else if ( e.ListChangedType == ListChangedType.Reset )
{
this.linkMonitorGrid.Table.ExpandAllGroups();
}
}

FYI - In the next version there will also be a PrimaryKeySortedRecords collection that you can then also use to quickly look up a record based on a primary key,
e.g.
Record r = this.linkMonitorGrid.Table.PrimaryKeySortedRecords[primaryKeyValue];

Stefan

[Jason Southgate]

Perfect Stefan, I did this, in the end and overloaded the method too to cover ListChangedType.Reset: private void OnLinkViewChanged ( object sender, ListChangedEventArgs e ) { // refresh the grid summaries this.linkMonitorGrid.Table.SummariesDirty = true; this.linkMonitorGrid.Refresh(); // if it''s an addition or an update if ( e.ListChangedType == ListChangedType.ItemAdded || e.ListChangedType == ListChangedType.ItemChanged ) { CheckForPossibleGridExpands( e.NewIndex ); } else if ( e.ListChangedType == ListChangedType.Reset ) { CheckForPossibleGridExpands(); } } private void CheckForPossibleGridExpands( int rowIndex ) { int status = Convert.ToInt16( this.linkMonitorGridView.Table.Rows[rowIndex]["Status"] ); // compare the new status with the one currently stored in the grid if ( status == 0 || status == 1 ) { Record r = this.linkMonitorGrid.Table.UnsortedRecords[rowIndex]; // expand the grid group r.ParentGroup.IsExpanded = true; } } private void CheckForPossibleGridExpands() { for ( int i=0; i

[Jason Southgate]

Sorry this was the overloaded method in the end: private void CheckForPossibleGridExpands() { for ( int i=0; i