How to display nested tables in the same level as the parent without being indented in WinForms GridGroupingControl?

Display nested table in same level

The child table can be displayed in the same level as the parent by hiding the default RecordPlusMinus buttons. To hide the +/- buttons, the TableOptions.ShowIndentTable property of the ChildTableDescriptor should be set to false. Then, the QueryCellStyleInfo and TableControlCellButtonClicked events have to be handled in a proper way to get this working. The following codes show how to achieve this.

Step 1: Setting the TableOptions.ShowIndent property.

//Sets ShowTableIndent to false for the ChildTable.
this.gridGroupingControl1.GetTableDescriptor("ChildTable").TableOptions.ShowTableIndent = false;

'Sets ShowTableIndent to false for the ChildTable.
Me.gridGroupingControl1.GetTableDescriptor("ChildTable").TableOptions.ShowTableIndent = False

Step 2: Handling the QueryCellStyleInfo event to format the PlusMinus buttons.

this.gridGroupingControl1.QueryCellStyleInfo += gridGroupingControl1_QueryCellStyleInfo;   
 
void gridGroupingControl1_QueryCellStyleInfo(object sender, Syncfusion.Windows.Forms.Grid.Grouping.GridTableCellStyleInfoEventArgs e)
{
   if(e.TableCellIdentity.TableCellType == GridTableCellType.NestedTableIndentCell)
   {
      if(e.TableCellIdentity.DisplayElement.Kind == DisplayElementKind.NestedTable)
      {
         // NestedTable.
         GridNestedTable nt = (GridNestedTable)e.TableCellIdentity.DisplayElement;
         foreach (Element el in nt.ChildTable.Elements)
         {
            if(el.Kind == DisplayElementKind.Record)
            {
                if(e.TableCellIdentity.RowIndex == this.gridGroupingControl1.Table.NestedDisplayElements.IndexOf(el))
                {
                   Record r = Record.GetParentRecord(el);
                   e.TableCellIdentity.TableCellType = GridTableCellType.RecordPlusMinusCell;
                   e.Style.Description = r.IsExpanded ? "-" : "+";      
                   e.Style.BorderMargins = new Syncfusion.Windows.Forms.Grid.GridMarginsInfo(3, 3, 3, 3);
                   e.Style.Themed = false;
                   e.Style.Enabled = true;
                }
            }
         }
      }
   }
}

AddHandler Me.gridGroupingControl1.QueryCellStyleInfo, AddressOf gridGroupingControl1_QueryCellStyleInfo

Private Sub gridGroupingControl1_QueryCellStyleInfo(ByVal sender As Object, ByVal e As Syncfusion.Windows.Forms.Grid.Grouping.GridTableCellStyleInfoEventArgs)
    If e.TableCellIdentity.TableCellType = GridTableCellType.NestedTableIndentCell Then
        If e.TableCellIdentity.DisplayElement.Kind = DisplayElementKind.NestedTable Then
            Dim nt As GridNestedTable = CType(e.TableCellIdentity.DisplayElement, GridNestedTable)
            For Each el As Element In nt.ChildTable.Elements
                If el.Kind = DisplayElementKind.Record Then
                    If e.TableCellIdentity.RowIndex = Me.gridGroupingControl1.Table.NestedDisplayElements.IndexOf(el) Then
                        Dim r As Record = Record.GetParentRecord(el)
                        e.TableCellIdentity.TableCellType = GridTableCellType.RecordPlusMinusCell
                        e.Style.Description = If(r.IsExpanded, "-", "+")
                        e.Style.BorderMargins = New Syncfusion.Windows.Forms.Grid.GridMarginsInfo(3, 3, 3, 3)
                        e.Style.Themed = False
                        e.Style.Enabled = True
                    End If
                End If
            Next
        End If
    End If
End Sub

Step 3: The TableControlCellButtonClicked event is responsible for expanding/collapsing the record when its RecordPlusMinus button is pressed.

this.gridGroupingControl1.TableControlCellButtonClicked += gridGroupingControl1_TableControlCellButtonClicked.
         
//Expands the Records on the plus/Minus button Click.
void gridGroupingControl1_TableControlCellButtonClicked(object sender, GridTableControlCellButtonClickedEventArgs e)
{
   GridTableCellStyleInfo style = this.gridGroupingControl1.Table.GetTableCellStyle(e.Inner.RowIndex, e.Inner.ColIndex);
   if(style.TableCellIdentity == null)
      return;
   if(style.TableCellIdentity.TableCellType == GridTableCellType.RecordPlusMinusCell)
   {
      if(style.TableCellIdentity.DisplayElement.Kind == DisplayElementKind.NestedTable)
      {
         //NestedTable.
         GridNestedTable nt = (GridNestedTable)style.TableCellIdentity.DisplayElement;
         foreach (Element el in nt.ChildTable.Elements)
         {
            if(el.Kind == DisplayElementKind.Record)
            {
               if(style.TableCellIdentity.RowIndex == this.gridGroupingControl1.Table.NestedDisplayElements.IndexOf(el))
               {
                  Record r = Record.GetParentRecord(el);
                  bool shouldExpand = !r.IsExpanded;
                  this.gridGroupingControl1.Table.CurrentRecord = r;
                  r.IsExpanded = shouldExpand;
                  e.Inner.Cancel = true;
               }
            }
         }
      }
   }
}

AddHandler Me.gridGroupingControl1.TableControlCellButtonClicked, AddressOf gridGroupingControl1_TableControlCellButtonClicked

Private Sub gridGroupingControl1_TableControlCellButtonClicked(ByVal sender As Object, ByVal e As GridTableControlCellButtonClickedEventArgs)
    Dim style As GridTableCellStyleInfo = Me.gridGroupingControl1.Table.GetTableCellStyle(e.Inner.RowIndex, e.Inner.ColIndex)
    If style.TableCellIdentity Is Nothing Then
        Return
    End If

    If style.TableCellIdentity.TableCellType = GridTableCellType.RecordPlusMinusCell Then
        If style.TableCellIdentity.DisplayElement.Kind = DisplayElementKind.NestedTable Then
            Dim nt As GridNestedTable = CType(style.TableCellIdentity.DisplayElement, GridNestedTable)
            For Each el As Element In nt.ChildTable.Elements
                If el.Kind = DisplayElementKind.Record Then
                    If style.TableCellIdentity.RowIndex = Me.gridGroupingControl1.Table.NestedDisplayElements.IndexOf(el) Then
                        Dim r As Record = Record.GetParentRecord(el)
                        Dim shouldExpand As Boolean = Not r.IsExpanded
                        Me.gridGroupingControl1.Table.CurrentRecord = r
                        r.IsExpanded = shouldExpand
                        e.Inner.Cancel = True
                    End If
                End If
            Next
        End If
    End If
End Sub