在Windows Mobile上的VB.NET中键入convertion

Question

I am maintaining an application for a Barcode-scanner running Windows Mobile with .NET 2.0 SP 1 and VB.NET. The application integrates with an Oracle database using PL/SQL.

I have a SQL-query that returns a DataTable with list of items to be picked with the scanner, and sometimes the quantity is a decimal number.

The problem is that I can't convert a decimal number such as 0,8 from string to double. I have tried all of the following:

Dim quantity As String = "0,8"
Dim result As Double = Convert.ToDouble(quantity)
Dim result As Double = Double.Parse(quantity)
Dim result As Double = CDbl(quantity)

In all cases the result is 8 and not 0,8.

Answer 1

The CF is limited in it's ability to parse. I assume the device culture is set to en-US, in which case you could do something like this:

Dim quantity As String = "0,8"
Dim result As Double = Double.Parse(quantity.Replace(',', '.'))

If you wanted it to be more locale-aware as far as the device's current setting, you could be more safe with something like this:

Dim quantity As String = "0,8"
Dim result As Double

If CultureInfo.CurrentCulture.NumberFormat.NumberDecimalSeparator == "."
    result = Double.Parse(quantity.Replace(',', '.'))
Else
    result = Double.Parse(quantity)
End If

Answer 2

Looks like your CurrentCulture has . as decimal separator and you're trying to parse value with , instead.

Try that:

System.Threading.Thread.Current.CurrentCulture.NumberFormat.NumberDecimalSeparator = ","
Dim result As Double = Double.Parse(quantity)