Inconsistent appearance between manual and coded versions of solid databar and databar minimum value

Question

I am trying to create solid databars in EPPlus 4.0.4, and am running into two problems.

• First, I haven't been able to figure out how to create a solid fill color.
• Second, at least for small values, the bars aren't showing up the way I expect them to.

The screenshot below illustrates both issues. In both cases, the desired outcome is that of the databar I've added manually in Excel:

This is the code I'm currently using:

var bars = doc.ConditionalFormatting.AddDatabar(range, Color.FromArgb(99,195,132));

bars.HighValue.Type = eExcelConditionalFormattingValueObjectType.Num;
bars.LowValue.Type = eExcelConditionalFormattingValueObjectType.Num;

bars.HighValue.Value = numResponses; //82
bars.LowValue.Value = 0;

For the solid color, I've been trying out variations of values for the different properties of bars.Style.Fill, to no avail. If this is implemented, it is a simple matter of me not finding the right property.

I'm having a harder time understanding the second issue. If I go into "Manage rule" in Excel, the high and low values are properly set, and I have found no value I can change them to that will make their appearance match that of the manually created bars.

Answer 1

This is an extension list problem. This comes up alot when getting into more complex exports. Conditional formatting is probably one of the tougher ones because there are so many nuances and it has changed so much over the years.

Extension list (extLst tags in xml) is kind of a catchall bucket that the OpenOfficeXml standard can use to added new features and formatting. In your case Excel populates the extension list section to allow for the extended min/max limit. Epplus does not support this which is why you see the difference.

Your simplest option would be just to inject it yourself via xml/string manipulation Not pretty but it gets the job done:

var bars = doc.ConditionalFormatting.AddDatabar(range, Color.FromArgb(99, 195, 132));

bars.HighValue.Type = eExcelConditionalFormattingValueObjectType.Num;
bars.LowValue.Type = eExcelConditionalFormattingValueObjectType.Num;

bars.HighValue.Value = numResponses; //82
bars.LowValue.Value = 0;

//Get reference to the worksheet xml for proper namespace
var xdoc = doc.WorksheetXml;
var nsm = new XmlNamespaceManager(xdoc.NameTable);
nsm.AddNamespace("default", xdoc.DocumentElement.NamespaceURI);

//Create the conditional format extension list entry
var extLstCf = xdoc.CreateNode(XmlNodeType.Element, "extLst", xdoc.DocumentElement.NamespaceURI);
extLstCf.InnerXml = @"<ext uri=""{B025F937-C7B1-47D3-B67F-A62EFF666E3E}"" xmlns:x14=""http://schemas.microsoft.com/office/spreadsheetml/2009/9/main""><x14:id>{3F3F0E19-800E-4C9F-9CAF-1E3CE014ED86}</x14:id></ext>";
var cfNode = xdoc.SelectSingleNode("/default:worksheet/default:conditionalFormatting/default:cfRule", nsm);
cfNode.AppendChild(extLstCf);

//Create the extension list content for the worksheet
var extLstWs = xdoc.CreateNode(XmlNodeType.Element, "extLst", xdoc.DocumentElement.NamespaceURI);
extLstWs.InnerXml = @"<ext uri=""{78C0D931-6437-407d-A8EE-F0AAD7539E65}"" xmlns:x14=""http://schemas.microsoft.com/office/spreadsheetml/2009/9/main""><x14:conditionalFormattings><x14:conditionalFormatting xmlns:xm=""http://schemas.microsoft.com/office/excel/2006/main""><x14:cfRule type=""dataBar"" id=""{3F3F0E19-800E-4C9F-9CAF-1E3CE014ED86}""><x14:dataBar minLength=""0"" maxLength=""100"" gradient=""0""><x14:cfvo type=""num""><xm:f>0</xm:f></x14:cfvo><x14:cfvo type=""num""><xm:f>82</xm:f></x14:cfvo><x14:negativeFillColor rgb=""FFFF0000""/><x14:axisColor rgb=""FF000000""/></x14:dataBar></x14:cfRule><xm:sqref>B2:B11</xm:sqref></x14:conditionalFormatting></x14:conditionalFormattings></ext>";
var wsNode = xdoc.SelectSingleNode("/default:worksheet", nsm);
wsNode.AppendChild(extLstWs);

pck.Save();

Note the gradient=""0"" which will set the color bars to solid instead of a gradient as well as the min/max settings to get the spread you are looking for.

A more "proper" way would be to would to recreate the xml objects node by node and attribute by attribute which will take a while but only have to do it once.