Question String to double

[Fury]

I have deployed an application for stock administration.
The user can make products with price and length...
Both have to be decimal so I converted the strings to doubles.
Everything works on the development computer also on another computer and a portable. The problem is only on the client's computer where there seems to be a problem with the conversion. Allways getting "Can not convert to double" error. How can that be when it's working on 3 other computers??

 

[Robert_Zenz]

Hello.

The question would be: What is he trying to convert or what is the client trying to enter?
Are you using a textbox for the input? If so you should switch to a NumericUpDown which is directly delivering a Double (or was it decimal?) as Value. Also you should really check what the client is entering (using if isnumeric()). Within a string a fullstop and a comma can make a huge difference depending on the local settings of the computer.

Bobby

 

[Fury]

Thank you for your reply.
They can only enter values like 7,5.
I programmed it so that a full stop is allways entered as a comma.

So it can be that they need a full stop depending on there local settings?
That was something I was thinking about.

How can I program to look for local settings so that the application knows if a full stop or a comma is needed?

 

[Robert_Zenz]

Yes, this can be. F.e. Within Europe the numbers are like 1.255.725,33 , in America and other countries it's turned around like 1,255,725.33 . You can check this by using the My.Computer Namespace:

My.Computer.Info.InstalledUICulture.NumberFormat

Is the spacebar also blocked? If not, that's a potential error source. .NET can convert numbers like " 5,5 ", but not "5, 5".

Bobby

 

[Fury]

Yes, the spacebar is also blocked.
I will use this code:

My.Computer.Info.InstalledUICulture.NumberFormat.NumberDecimalSeparator

Thanks , I think that will be the problem.

 

[Fury]

So there regional settings are correct.
Still they have this error that the string couldn't be converted.
Now I really don't know what the problem could be.

 

[Robert_Zenz]

Can you show us the part of the code where this conversion takes place?

 

[Fury]

The first part is validation code.

If Char.IsDigit(e.KeyChar) Then
            e.Handled = False
        ElseIf e.KeyChar = vbBack Then
            e.Handled = False
        ElseIf e.KeyChar = "." Then
            If TextBoxLength.Text.IndexOf(",") > -1 Then
                e.Handled = True
            Else
                e.KeyChar = CChar(",")
            End If
        ElseIf e.KeyChar = "," Then
            If TextBoxLength.Text.IndexOf(",") > -1 Then
                e.Handled = True
            Else
                e.Handled = False
            End If
            Else
                e.Handled = True
        End If

        If TextBoxLength.Text.Length = 0 Then
            If e.KeyChar = "," Or e.KeyChar = "." Then
                e.Handled = True
            End If
        End If

The second part is where I cast string length into double.

Dim profile As New BusinessEntity.Profile

                    With profile

                        .ProductName = TextBoxDescription.Text
                        .Min = CType(TextBoxMin.Text, Integer)
                        .Max = CType(TextBoxMax.Text, Integer)
                        .VitraluxCode = TextBoxVitraluxcode.Text
                        .Length = CType(TextBoxLength.Text, Double)
                        If CheckBoxThermal.Checked Then
                            .Thermal = True
                        Else
                            .Thermal = False
                        End If
                        .Activity = True
                        .Type = "Profiel"
                        If ComboBoxColor.Enabled Then
                            .ColorID = CType(ComboBoxColor.SelectedValue, Integer)
                        Else
                            .ColorID = Nothing
                        End If

                    End With

I hope you can help me with this.

 

[Robert_Zenz]

That's pretty odd...but hard to say without access to a computer where it's not working.

What's the exact error Message? (A little guessing is within this, since I'm using a German Visual Studio)

String  couldn't be converted to Double

or

String 7,5 couldn't be converted to Double

Normally he tries to print the string, which he couldn't convert, within the error message (as shown above). If there's no string but a double space then there's something really wrong, like he couldn't read the Text property.

Normally it could only be a faulty character, but I can't imagine that your client is entering Alt-Codes or something similar. You could also try to use CDbl instead, since this is an explicit conversion to Double, but I don't think that this would make any difference...but maybe.

Sorry, but this is a really weird problem...I'm just guessing at the moment...

 

[Fury]

The error is: String 7,5 couldn't be converted to Double.