Sum DataTable columns of type string

问题

how do i calculate Sum of two rows in datatable which is of type string ?
in my case i cannot change column type.
i tried these :

1) object objSum;
objSum = dt.Compute("Sum(WeightRate)", "");

2) decimal total = (decimal)dt.Compute("SUM( [WeightRate] )", "");

but no luck...

My table :
Weightrate No.Ofvehicles
350.50 50
205.00 40

I need result as

Weightrate No.Ofvehicle
555.50 90

回答1:

The Compute method allows for some rudimentary type conversion:

var sum = dt.Compute("Sum(Convert(WeightRate, 'System.Int32'))");

See the MSDN help on DataColumn Expressions for more information about what you can do with a Compute method call.

Edit Having re-read your question, you'll probably want to convert to System.Decimal rather than System.Int32, but hopefully you got that. ;-)

来源：https://stackoverflow.com/questions/708299/sum-datatable-columns-of-type-string