Want to win a PS4? Go Premium and enter to win our High-Tech Treats giveaway. Enter to Win

x
?
Solved

Trying to SUM listbox items, but getting "Conversion from type 'ListItem' to type 'String' is not valid". Need someone to check code.

Posted on 2013-05-20
3
Medium Priority
?
538 Views
Last Modified: 2013-05-21
Hello,
can someone please advise what I'm doing wrong. I have try many solutions, but just cannot get out from error like:
"Conversion from type 'ListItem' to type 'String' is not valid", or
Conversion from type 'ListItem' to type 'Double' is not valid, or
Conversion from type 'ListItem' to type 'Integer' is not valid, etc

Dim result As Double = Math.Round((TextBoxA.Text + TextBoxB.Text, 1)
        MsgBox(result)
        Dim Pcs As String = result * TextBoxC.Text
        MsgBox(Pcs)
        ListBox1.Items.Add(Pcs)
        Dim sum As Double
        For Each item As String In ListBox1.Items
            sum += Double.Parse(item)
        Next

Open in new window


Thanks in advance for hlep!
0
Comment
Question by:dejandejanovic
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 2
3 Comments
 
LVL 42

Expert Comment

by:Meir Rivkin
ID: 39182638
Dim result As Double = Math.Round((TextBoxA.Text + TextBoxB.Text, 1)
        MsgBox(result)
        Dim Pcs As String = result * TextBoxC.Text
        MsgBox(Pcs)
        ListBox1.Items.Add(Pcs)
        Dim sum As Double
        For Each item As Object In ListBox1.Items
            sum += Double.TryParse(item.ToString())
        Next

Open in new window

0
 
LVL 42

Accepted Solution

by:
Meir Rivkin earned 2000 total points
ID: 39182646
better yet with TryParse to avoid exception:
Dim result As Double = Math.Round((TextBoxA.Text + TextBoxB.Text, 1)
        MsgBox(result)
        Dim Pcs As String = result * TextBoxC.Text
        MsgBox(Pcs)
        ListBox1.Items.Add(Pcs)
        Dim sum As Double
        Dim number As Double
        For Each item As Object In ListBox1.Items
            if (Double.TryParse(item.ToString(), number)) then
                sum += number
        else
                'parsing failed
        end if
        Next

Open in new window

0
 

Author Closing Comment

by:dejandejanovic
ID: 39183887
Works perfect! Thanks.
0

Featured Post

Tech or Treat!

Submit an article about your scariest tech experience—and the solution—and you’ll be automatically entered to win one of 4 fantastic tech gadgets.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

I recently went through the process of creating a Calendar Control of events with the basis of using a database to keep track of the dates that are selectable, one requirement was to have the selected date pop-up in a simple lightbox.  At first this…
IntroductionWhile developing web applications, a single page might contain many regions and each region might contain many number of controls with the capability to perform  postback. Many times you might need to perform some action on an ASP.NET po…
Sometimes it takes a new vantage point, apart from our everyday security practices, to truly see our Active Directory (AD) vulnerabilities. We get used to implementing the same techniques and checking the same areas for a breach. This pattern can re…
In a question here at Experts Exchange (https://www.experts-exchange.com/questions/29062564/Adobe-acrobat-reader-DC.html), a member asked how to create a signature in Adobe Acrobat Reader DC (the free Reader product, not the paid, full Acrobat produ…
Suggested Courses

636 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question