Array Problem With Datatable?

[VonEhle]

I have a datatable that keeps a running cost total of all items in the table. I'm trying to make it so I can also keep track of each individual line for future purposes. When I run it as shown below, I get an error that says "Object reference not set to an instance of an object." The error points to the line of code with the array.

For intCounter = 0 To objDT.Rows.Count - 1
objDR = objDT.Rows(intCounter)
decLineCost = (objDR("Cost") * objDR("Quantity"))
decRunningTotal += decLineCost
[COLOR=red]strLineCost(intCounter) = decLineCost.ToString[/COLOR]
Next

 

[lingsn]

I think the error is from

[COLOR=#ff0000]strLineCost(intCounter)[/COLOR]

Had you initialise the strLineCost. For example

Dim strLineCost() as String
Redim strLineCost(50)

 

[jmcilhinney]

I would suggest adding another column to your DataTable and setting its Expression property to "Cost * Quantity". It will than automatically calculate the value for you. If you want the total amount for the table you would then use the Compute method, e.g. myDataTable.Compute("SUM(Amount)"), which will return a single value that sums your entire calculated column.