Totals - SUM problem

danni

Hi

the expression for a total I convert a String to a Decimal.

When the databand I SUM over is empty, I get a conversion exception.

Note: I print the first row if the databand is empty.

AlexTZ

Hello,

FastReport cannot handle this. It's up to you to convert a string to decimal correctly. You may create own function in the report code that performs the conversion and checks for empty values.

danni

It's too about wether the values in the reportobjects are empty. It's if the datasource for a band is emty, not NULL but just en empty list.

The ToDecimal(object obj) function should and do convert object values to a decimal, BUT it shouldnt be called if the datasource is empty. I have no way to correct this when using the Totals-SUM function as I see it.

AlexTZ

Since you are using the PrintIfDataSourceEmpty option of a databand, everything is called as expected.
Could you make a simple demo for me and send it to tz@fast-report.com? Maybe I misunderstood something...

danni

Hi again.
I have to take it back - I think.

My colleague made a copy of a report that has a Total(sum).

On the copy, the reportobject [Total] was reomved without removing it from the list in the Data window.

This means that the expression in the list of Totals is validated no matter if it is draged on to the report?

We fixed it by deleting the Total.

AlexTZ

That's true, every total is calculated, no matter if it is actually used in a report object.

danni

How do I avoid getting a parsing error when the dataource is empty (for the validated reportobject)?

in my sum function I try to convert a string to a decimal.

Somehow I need to check if the databand is empty within my expression?

AlexTZ

You may write own script function and use it instead of ToDouble standard function. Something like this:

private double TryToDouble(string value)
{
  try
  {
    return ToDouble(value);
  }
  catch
  {
    return 0;
  }
}

danni

Ok, Will do that.

I would think your standard functions had a default return value and used a try/catch?