Infragistics(R) NetAdvantage(R) Windows Forms
ICustomSummaryCalculator Interface
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Infragistics.Win.UltraWinGrid Namespace : ICustomSummaryCalculator Interface

Interface user would implement to calculate custom summaries. SummarySettings.CustomSummaryCalculator for more information.

Syntax

Visual Basic (Declaration) 
Public Interface ICustomSummaryCalculator 
C# 
public interface ICustomSummaryCalculator 

Example

Following code adds a custom summary for calculating totals for customer orders. OrderTotalsSummary class defined above implements ICustomSummaryCalculator interface necessary to calculate custom summaries in UltraGrid.

Visual BasicCopy Code
Imports Infragistics.Shared
Imports Infragistics.Win
Imports Infragistics.Win.UltraWinGrid

  ' A class that calculates the totals for orders.
  Private Class OrderTotalsSummary
      Implements ICustomSummaryCalculator

      Private totals As Decimal = 0

      Public Sub New()
      End Sub

      Private Sub BeginCustomSummary(ByVal summarySettings As SummarySettings, ByVal rows As RowsCollection) Implements ICustomSummaryCalculator.BeginCustomSummary

          ' Begins the summary for the SummarySettings object passed in. Implementation of 
          ' this method should reset any state variables used for calculating the summary.
          Me.totals = 0

      End Sub

      Private Sub AggregateCustomSummary(ByVal summarySettings As SummarySettings, ByVal row As UltraGridRow) Implements ICustomSummaryCalculator.AggregateCustomSummary

          ' Here is where we process each row that gets passed in.

          Dim unitPrice As Object = row.GetCellValue(summarySettings.SourceColumn.Band.Columns("Unit Price"))
          Dim quantity As Object = row.GetCellValue(summarySettings.SourceColumn.Band.Columns("Quantity"))

          ' Handle null values
          If unitPrice Is DBNull.Value Or quantity Is DBNull.Value Then
              Return
          End If

          ' Convert to decimal.
          Try
              Dim nUnitPrice As Decimal = Convert.ToDecimal(unitPrice)
              Dim nQuantity As Decimal = Convert.ToDecimal(quantity)

              Me.totals += nQuantity * nUnitPrice
          Catch e As Exception
              ' This should not happen if the columns are numeric.
              Debug.Assert(False, "Exception thrown while trying to convert cell's value to decimal !")
          End Try

      End Sub

      Private Function EndCustomSummary(ByVal summarySettings As SummarySettings, ByVal rows As RowsCollection) Implements ICustomSummaryCalculator.EndCustomSummary

          ' This gets called when the every row has been processed so here is where we
          ' would return the calculated summary value.
          Return Me.totals

      End Function
  End Class

  Private Sub Button12_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles button12.Click

      Dim band As UltraGridBand = Me.ultraGrid1.DisplayLayout.Bands(2)

      ' Add the OrderTotals custom summary.
      Dim summary As SummarySettings = band.Summaries.Add("OrderTotals", SummaryType.Custom, _
          New OrderTotalsSummary(), band.Columns("Unit Price"), SummaryPosition.Left, Nothing)

      ' Set the format with which to format the calculated summary when displaying
      ' in the summary footer.
      summary.DisplayFormat = "Sales Total = {0:######.00}"

      ' Set the horizontal text align to right so that the text summary text is aligned
      ' right in the summary element.
      summary.Appearance.TextHAlign = HAlign.Right

      ' Set the summary position to Left so that it shows up on the left of the
      ' summary footer area.
      summary.SummaryPosition = SummaryPosition.Right

      ' Set the appearance of the summary.
      summary.Appearance.FontData.Bold = DefaultableBoolean.True
      summary.Appearance.ForeColor = Color.Maroon
      summary.Appearance.BackColor = Color.LightGray

      ' Set the text that shows up in the caption of the summary footer.
      band.SummaryFooterCaption = "Total Sales for Order (OrderID)"

      ' Set the appearance of the summary footer area.
      Me.ultraGrid1.DisplayLayout.Override.SummaryFooterAppearance.FontData.Bold = DefaultableBoolean.True
      Me.ultraGrid1.DisplayLayout.Override.SummaryFooterAppearance.BackColor = Color.White
      Me.ultraGrid1.DisplayLayout.Override.SummaryFooterAppearance.ForeColor = Color.Black

      ' Set the appearance for the caption on top of the summary area.
      Me.ultraGrid1.DisplayLayout.Override.SummaryFooterCaptionVisible = DefaultableBoolean.True
      Me.ultraGrid1.DisplayLayout.Override.SummaryFooterCaptionAppearance.BackColor = Color.DarkBlue
      Me.ultraGrid1.DisplayLayout.Override.SummaryFooterCaptionAppearance.ForeColor = Color.LightYellow

  End Sub
C#Copy Code
using Infragistics.Shared;
using Infragistics.Win;
using Infragistics.Win.UltraWinGrid;
using System.Diagnostics;

// A class that calculates the totals for orders.
private class OrderTotalsSummary : ICustomSummaryCalculator 
{
	private decimal totals = 0;

	internal OrderTotalsSummary( )
	{
	}

	public void BeginCustomSummary( SummarySettings summarySettings, RowsCollection rows )
	{

		// Begins the summary for the SummarySettings object passed in. Implementation of 
		// this method should reset any state variables used for calculating the summary.
		this.totals = 0;

	}

	public void AggregateCustomSummary( SummarySettings summarySettings, UltraGridRow row )
	{

		// Here is where we process each row that gets passed in.

		object unitPrice = row.GetCellValue( summarySettings.SourceColumn.Band.Columns["Unit Price"] );
		object quantity = row.GetCellValue( summarySettings.SourceColumn.Band.Columns["Quantity"] );

		// Handle null values
		if ( unitPrice is DBNull || quantity is DBNull )
		{
			return;
		}

		// Convert to decimal.
		try
		{
			decimal nUnitPrice = Convert.ToDecimal( unitPrice );
			decimal nQuantity = Convert.ToDecimal( quantity );

			this.totals += nQuantity * nUnitPrice;
		}
		catch ( Exception )
		{
			// This should not happen if the columns are numeric.
			Debug.Assert( false, "Exception thrown while trying to convert cell's value to decimal !" );
		}

	}

	
	public object EndCustomSummary( SummarySettings summarySettings, RowsCollection rows )		
	{

		// This gets called when the every row has been processed so here is where we
		// would return the calculated summary value.
		return this.totals;

	}
}

private void button12_Click(object sender, System.EventArgs e)
{

	UltraGridBand band = this.ultraGrid1.DisplayLayout.Bands[2];

	// Add the OrderTotals custom summary.
	SummarySettings summary = band.Summaries.Add( 
		"OrderTotals",					// Give an identifier (key) for this summary
		SummaryType.Custom,				// Summary type is custom
		new OrderTotalsSummary( ),		// Our custom summary calculator
		band.Columns["Unit Price"],		// Column being summarized. Just use Unit Price column.
		SummaryPosition.Left,			// Position the summary on the left of summary footer
		null							// Since SummaryPosition is Left, pass in null
		);
	
	// Set the format with which to format the calculated summary when displaying
	// in the summary footer.
	summary.DisplayFormat = "Sales Total = {0:######.00}";

	// Set the horizontal text align to right so that the text summary text is aligned
	// right in the summary element.
	summary.Appearance.TextHAlign = HAlign.Right;

	// Set the summary position to Left so that it shows up on the left of the
	// summary footer area.
	summary.SummaryPosition = SummaryPosition.Right;

	// Set the appearance of the summary.
	summary.Appearance.FontData.Bold = DefaultableBoolean.True;
	summary.Appearance.ForeColor = Color.Maroon;
	summary.Appearance.BackColor = Color.LightGray;

	// Set the text that shows up in the caption of the summary footer.
	band.SummaryFooterCaption = "Total Sales for Order [OrderID]";

	// Set the appearance of the summary footer area.
	this.ultraGrid1.DisplayLayout.Override.SummaryFooterAppearance.FontData.Bold = DefaultableBoolean.True;
	this.ultraGrid1.DisplayLayout.Override.SummaryFooterAppearance.BackColor = Color.White;
	this.ultraGrid1.DisplayLayout.Override.SummaryFooterAppearance.ForeColor = Color.Black;
	
	// Set the appearance for the caption on top of the summary area.
	this.ultraGrid1.DisplayLayout.Override.SummaryFooterCaptionVisible = DefaultableBoolean.True;
	this.ultraGrid1.DisplayLayout.Override.SummaryFooterCaptionAppearance.BackColor = Color.DarkBlue;
	this.ultraGrid1.DisplayLayout.Override.SummaryFooterCaptionAppearance.ForeColor = Color.LightYellow;

}

See Also