How do I do use the custom code and format for a percentage with 2 decimals in Report Builder 3.0?

Question

In Report Builder 3.0, I have the following custom code entered:
  Public Function SafeDivide(Numerator as String, Denominator as String) as String
Try
If Numerator = “” or Denominator = “” then
Return “-“
End if
If Numerator = “-“ or Denominator = “-“ then
Return “-“
End If
If CDbl(Numerator) =0 or CDbl(Denominator) = 0 then
Return “-“
End if
If IsNothing(Numerator) or IsNothing(Denominator) then
Return "-"
End if
Return Val( ( (CDbl(Numerator) / CDbl(Denominator) )*100 ) )
Catch
Return "-"
End Try
End Function
I call the custom code in the cell with the following equation:
  =Code.SafeDivide(sum(Fields!TY_UNITS.Value)-sum(Fields!LY_UNITS.Value),sum(Fields!LY_UNITS.Value))
I have the format for the cell set to 0.00%, but it’s not being followed.
I want the result to be formatted as a Percentage, but instead I get values like: 
-78.9473684210
80
300
-100
I have the format for the cell set to 0.00%, but it’s not being followed.
How do I do use the custom code and format for a percentage with 2 decimals?

Answer 1

Hi AngP,
After testing the issue in my local environment, I can reproduce it. Based on my research, I find this issue is caused by the type of Units_VAR_Percentage cell is string, while the type of CDbl(Parameters!Var_Threshold.Value) is double, so they cannot be
compared.
To fix this issue, we can add a hidden column (Textbox91) next to the Units_VAR_Percentage column, and type =(sum(Fields!TY_UNITS.Value)-sum(Fields!LY_UNITS.Value)) /sum(Fields!LY_UNITS.Value) as the expression. Then use the expression below to control the
BackgroundColor:
=iif(iif(reportitems!Units_VAR_Percentage.Value=CStr(format(reportitems!Textbox91.Value,"0.00%")),reportitems!Textbox91.Value,0)>CDbl(Parameters!Var_Threshold.Value),"Yellow","PaleTurquoise")
If there are any other questions, please feel free to ask.
Thanks,
Katherine Xiong
Katherine Xiong
TechNet Community Support