fpSpread1.Sheets[0].Cells[0, 0].Value = 2;
fpSpread1.Sheets[0].Cells[1, 0].Value = -1;
fpSpread1.Sheets[0].Cells[3, 0].Value = 3;
FarPoint.Win.Spread.DatabarConditionalFormattingRule dataBarRule = new FarPoint.Win.Spread.DatabarConditionalFormattingRule();
dataBarRule.AxisPosition = FarPoint.Win.Spread.DataBarAxisPosition.Automatic;
dataBarRule.BorderColor = Color.Blue;
dataBarRule.NegativeFillColor = Color.Red;
dataBarRule.Gradient = true;
dataBarRule.Maximum = new FarPoint.Win.Spread.ConditionalFormattingValue(FarPoint.Win.Spread.ConditionalFormattingValueType.AutoMax);
dataBarRule.Minimum = new FarPoint.Win.Spread.ConditionalFormattingValue(FarPoint.Win.Spread.ConditionalFormattingValueType.AutoMin);
dataBarRule.UseNegativeFillColor = true;
dataBarRule.UseNegativeBorderColor = false;
FarPoint.Win.Spread.ConditionalFormatting cf = new FarPoint.Win.Spread.ConditionalFormatting(new FarPoint.Win.Spread.Model.CellRange(0, 0, 4, 1));
cf.Add(dataBarRule);
fpSpread1.ActiveSheet.Models.ConditionalFormatting.Add(cf);