EPPlus two color conditional date format - epplus

Question

I have a column with dates and I want to conditionally color any cell that is older that 2 week yellow, and any that is older than 90 days red. I can't figure out how to do that.

Answer 1

Should be able to just add the conditions like any other. You can use the TODAY() function in excel and subtract:
[TestMethod]
public void Conditional_Formatting_Date()
{
//https://stackoverflow.com/questions/56741642/epplus-two-color-conditional-date-format
var file = new FileInfo(#"c:\temp\Conditional_Formatting_Date.xlsx");
if (file.Exists)
file.Delete();
//Throw in some data
var dataTable = new DataTable("tblData");
dataTable.Columns.AddRange(new[] {
new DataColumn("Col1", typeof(DateTime)),
new DataColumn("Col3", typeof(string))
});
var rnd = new Random();
for (var i = 0; i < 100; i++)
{
var row = dataTable.NewRow();
row[0] = DateTime.Now.AddDays(-rnd.Next(1, 100));
row[1] = $"=TODAY() - A{i +1}";
dataTable.Rows.Add(row);
}
//Create a test file
using (var package = new ExcelPackage(file))
{
//Make the stylesheet
var ws = package.Workbook.Worksheets.Add("table");
var range = ws.Cells[1, 1].LoadFromDataTable(dataTable, false);
ws.Column(1).Style.Numberformat.Format = "mm-dd-yy";
ws.Column(1).AutoFit();
//Add the calc check
var count = 0;
foreach (DataRow row in dataTable.Rows)
ws.Cells[++count, 2].Formula = row[1].ToString();
//Add the conditions - order matters
var rangeA = range.Offset(0, 0, count, 1);
var condition90 = ws.ConditionalFormatting.AddExpression(rangeA);
condition90.Style.Font.Color.Color = Color.White;
condition90.Style.Fill.PatternType = ExcelFillStyle.Solid;
condition90.Style.Fill.BackgroundColor.Color = Color.Red;
condition90.Formula = "TODAY() - A1> 90";
condition90.StopIfTrue = true;
var condition14 = ws.ConditionalFormatting.AddExpression(rangeA);
condition14.Style.Font.Color.Color = Color.Black;
condition14.Style.Fill.PatternType = ExcelFillStyle.Solid;
condition14.Style.Fill.BackgroundColor.Color = Color.Yellow;
condition14.Formula = "TODAY() - A1> 14";
package.Save();
}
}
Which gives this in the output:

Answer 2

I am assuming that you have the column number of the date column and number of rows in your records. Also, the following loop is under assumption that the first row is your column header and records begin from second row. Change the loop counter's initialization and assignment accordingly.
int rowsCount; //get your no of rows
int dateColNumber; //Assign column number in excel file of your date column
string cellValue;
DateTime dateValue;
DateTime today = DateTime.Now;
double daysCount;
for(int i=1;i<rowsCount;i++)
{
cellValue = ws.Cells[i + 1, dateColNumber].Text.ToString(); //First row is header start from second
if(DateTime.TryParse(cellValue,out dateValue))
{
daysCount = (today - dateValue).Days;
if(daysCount>90)
{
ws.Cells[i + 1,dateColNumber].Style.Fill.PatternType = OfficeOpenXml.Style.ExcelFillStyle.Solid;
ws.Cells[i + 1,dateColNumber].Style.Fill.BackgroundColor.SetColor(System.Drawing.Color.Red);
}
else if(daysCount>14)
{
ws.Cells[i + 1, dateColNumber].Style.Fill.PatternType = OfficeOpenXml.Style.ExcelFillStyle.Solid;
ws.Cells[i + 1, dateColNumber].Style.Fill.BackgroundColor.SetColor(System.Drawing.Color.Yellow);
}
}
}