VB Can't Convert String to Decimal

[JT8101997]

I'm trying to write some code for a program i'm working on, but i'm having a problem. I wrote the code i need help with in bold, but i included the rest of the sub so you could see what's going on.

 

Example:

If LVL1.Visible And My.Forms.LVL1.lblFinish.BackColor = Color.Black Then

            lbl1.Text = My.Forms.LVL1.lblScore.Text

        End If

        'Level 2

        If LVL2.Visible And My.Forms.LVL2.lblFinish.BackColor = Color.Black Then

            lbl2.Text = My.Forms.LVL2.lblScore.Text

        End If

        'Level 3

        If LVL3.Visible And My.Forms.LVL3.lblFinish.BackColor = Color.Black Then

            lbl3.Text = My.Forms.LVL3.lblScore.Text

        End If

        'Level 4

        If LVL4.Visible And My.Forms.LVL4.lblFinish.BackColor = Color.Black Then

            lbl4.Text = My.Forms.LVL4.lblScore.Text

        End If

        'Level 5

        If LVL5.Visible And My.Forms.LVL5.lblFinish.BackColor = Color.Black Then

            lbl5.Text = My.Forms.LVL5.lblScore.Text

        End If

        'Level 6

        If LVL6.Visible And My.Forms.LVL6.lblFinish.BackColor = Color.Black Then

            lbl6.Text = My.Forms.LVL6.lblScore.Text

        End If

lblTotalScore.Text = lbl1.Text + lbl2.Text + lbl3.Text + lbl4.Text + lbl5.Text + lbl6.Text

 

 

But my problem is that it adds them as strings so the value of each appears next to each other. I want to add the values of each, so i used CDec() for each one, but i got an error saying it was not formated properly. I've had this happen multiple times with different code in this program. Kinda urgent as this is the final piece i need to work and this is due on tuesday next week. Thanks everyone.

[Neil]

Try:

lblTotalScore.Text = CDbl(lbl1.Text) + CDbl(lbl2.Text) + CDbl(lbl3.Text) + CDbl(lbl4.Text) + CDbl(lbl5.Text) + CDbl(lbl6.Text)

(https://msdn.microsoft.com/en-us/library/s2dy91zy.aspx)

[JT8101997]

Try:

lblTotalScore.Text = CDbl(lbl1.Text) + CDbl(lbl2.Text) + CDbl(lbl3.Text) + CDbl(lbl4.Text) + CDbl(lbl5.Text) + CDbl(lbl6.Text)

(https://msdn.microsoft.com/en-us/library/s2dy91zy.aspx)

Just tried it. Gives me this every time. Just replace double with integer, decimal, etc.

 

Conversion from string "" to type 'Double' is not valid.

 

EDIT: this is under a timer tick sub if that matters.

[Reno2792]

Can you create variables for each of the labels. and then just add them and then convert the result to the totalscore label?

  Dim var01 As Decimal = Convert.ToDecimal(Label1.Text)

  Dim var02 As Decimal = Convert.ToDecimal(Label2.Text)

  Dim result As Decimal = var01 + var02

 

  Label3.Text = Convert.ToString(result)

[Neil]

@Reno2792's answer is good--that should work great

[madknight3]

 

Just tried it. Gives me this every time. Just replace double with integer, decimal, etc.

 

Conversion from string "" to type 'Double' is not valid.

 

EDIT: this is under a timer tick sub if that matters.

 

An empty string (ie: "") isn't a valid number so your conversion is throwing an exception.

// this worksDim s As String = "6.55"Dim d As Decimal = CDec(s)// this throws an exceptionDim s As String = ""Dim d As Decimal = CDec(s)// Also note that these don't throw an exception// but instead and just converts to 0Dim s As StringDim d As Decimal = CDec(s)Dim s As String = NothingDim d As Decimal = CDec(s)

You have some options depending on how you want to handle it. You can check that the string isn't empty before you call the conversion method on it, you can use a TryParse method (ex: Decimal.TryParse), or you can use try/catch statements to handle the exception.

[JT8101997]

 

Can you create variables for each of the labels. and then just add them and then convert the result to the totalscore label?

  Dim var01 As Decimal = Convert.ToDecimal(Label1.Text)

  Dim var02 As Decimal = Convert.ToDecimal(Label2.Text)

  Dim result As Decimal = var01 + var02

 

  Label3.Text = Convert.ToString(result)

 

Tried it. I got this.

 

"Input string was not in a correct format."

 

Idk what's wrong with this, because that's the code that should work.

OMFG I HATE VB. Can't wait to be done with this class so i can learn something more useful with my time -__-

I'm beginning to think it's just an error with visual studio and not actually my code at all.

[madknight3]

Tried it. I got this.

 

"Input string was not in a correct format."

 

See my above answer about converting empty strings. The same thing is happening here only because you're using a different method, Convert.ToDecimal instead of CDec, it's just throwing a different exception. 

[Neil]

Yeah... must've overlooked that sorry. Your real issue here is that your strings are empty, as @madknight3 said... Have you tried printing them out/showing them individually to make sure they show the content you're looking for?

[JT8101997]

See my above answer about converting empty strings. The same thing is happening here only because you're using a different method, Convert.ToDecimal instead of CDec, it's just throwing a different exception. 

How would i do that though? I'm just confused by that. I understand the code but the problem is that I'm not declaring it as a string. It just turns itself into that and wont let me convert it back. This is for a game and it pulls the score from each level and i wanted it to add them all together to give you a total score for the chapter which has these six levels in it, but i can't do that.

[JT8101997]

Yeah... must've overlooked that sorry. Your real issue here is that your strings are empty, as @madknight3 said... Have you tried printing them out/showing them individually to make sure they show the content you're looking for?

How would i fix that then? I don't see why they're empty they should contain the value of the labels text though right?

[madknight3]

How would i do that though? I'm just confused by that. I understand the code but the problem is that I'm not declaring it as a string. It just turns itself into that and wont let me convert it back. This is for a game and it pulls the score from each level and i wanted it to add them all together to give you a total score for the chapter which has these six levels in it, but i can't do that.

 

Many controls like Labels and TextBoxes have a Text property. These require what they display to be a String. So even if you put a Decimal into the Text field, VB automatically converts it to a String for you and you'll get a String when you get it out of the Text property.

// Given your decimalDim d As New Decimal(6.55)// doing this will turn it into a stringLabel1.Text = d// the result is the same as thisLabel1.Text = d.ToString()// So now when using the Label1.Text, you have to treat it as a stringDim s As String = Label1.Text

[JT8101997]

I think i fixed it actually. Instead of leaving the labels blank i just put 0 into the text for each, because it was trying to add them all before i completed every level, so there was no score yet and that's why it was empty. Thank you all for the help I should be fine now.

[Reno2792]

How about this to stop the error.

 

Dim var01 As Decimal = Nothing

        Dim var02 As Decimal = Nothing

 

 

        If (Label1.Text.Equals("")) Then

            Label1.Text = 0.0

        End If

 

        If (Label2.Text.Equals("")) Then

            Label2.Text = 0.0

        End If

 

        var01 = Convert.ToDecimal(Label1.Text)

        var02 = Convert.ToDecimal(Label2.Text)

 

        Dim result As Decimal = var01 + var02

 

        Label3.Text = Convert.ToString(result)

[madknight3]

I think i fixed it actually. Instead of leaving the labels blank i just put 0 into the text for each, because it was trying to add them all before i completed every level, so there was no score yet and that's why it was empty. Thank you all for the help I should be fine now.

 

Yes, that is another way to get it to work. If you don't allow something to be an empty string, then it can't throw that exception. The others I mentioned are good to learn though as you may need them in other situations.

Dim s As String = Label1.TextDim d As Decimal// Check for empty stringIf s.Equals("") Then    // Do something to prevent exception    // Before calling CDec(s)End If// Use TryParseIf (Decimal.TryParse(s, d)) Then    // Conversion successful    // d contains the converted valueElse    // Conversion failed    // d contains zeroEnd If// Use try/catchTry    CDec(s)Catch ex As Exception    // Do something in the case of an exception    // For example, set d to zeroEnd Try