Input Output Function Error
 

I am receiving an error. Conversion from string "" to type 'Double' is not valid.

I will show you the code. It seems to be coming from the variable that I was trying to create so that I could store the information from the sundaypm.txt file. And I wanted to compare it to that number that was stored in the file which is "15" and then to place the difference of that number and a number entered into the textbox in this particular form into another form called sundayResultsForm. Here is the code. Please help with this.


Public Class userForm

Friend cparecommendation
Friend cpaadminsundaycount


Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click


Dim messageString
Dim usersundayString As String = usersundaycpaTextBox.Text
Dim cpaMaxDecimal As Decimal = usersundayString - cpaadminsundaycount



If usersundaycpaTextBox.Text > cpaadminsundaycount Then
messageString = "You have " & cpaMaxDecimal & " player(s) available for hire."
cparecommendation = messageString
End If

' Open the file for output.

Dim fileReader As String
FileOpen(1, "Sundaypm.txt", OpenMode.Input)

fileReader = My.Computer.FileSystem.ReadAllText("Sundaypm.txt")
MsgBox(fileReader)
cpaadminsundaycount = MsgBox(fileReader)
sundayResultsForm.ShowDialog()


FileClose(1)




End Sub
End Class

Re: Input Output Function Error
 

Try CType.. that should help you out.

Re: Input Output Function Error
 

Also, next time, maybe a line number on where the error is...

Re: Input Output Function Error
 

Thank you for your reply. I am not sure how to use the ctype, I visited the link but I don't know how or where or what to put in the example that I saw. But here is the error line


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


The error is highlighting this line in the code
Dim cpaMaxDecimal As Decimal = usersundayString - cpaadminsundaycount

and pointing to "cpaadminsundaycount"

Re: Input Output Function Error
 

Dim cpaMaxDecimal As Decimal = CType(usersundayString, Decimal) - CType(cpaadminsundaycount, Decimal)

Is what you need. I'm a little drunk, but it looks good to me.

Re: Input Output Function Error
 

This is the error I am getting.

InvalidCastException was unhandled.
Conversion from string "" to type Decimal' is not valid

on the same line pointing to the same area "Ctype(cpaadminsundaycount, Decimal)

I'm stumped

Re: Input Output Function Error
 

Sorry, I think that it is line 15 from the original code above with the Ctype added instead.

Re: Input Output Function Error
 

What is teh value of "cpaadminsundaycount" ?

Re: Input Output Function Error
 

Dim fileReader As String
FileOpen(1, "Sundaypm.txt", OpenMode.Input)

fileReader = My.Computer.FileSystem.ReadAllText("Sundaypm.txt")
MsgBox(fileReader)
cpaadminsundaycount = MsgBox(fileReader)
sundayResultsForm.ShowDialog()


The value is the number that I have in my Sundaypm.txt file which is 15
it actually shows in the file 15,

That number can change if the admin changes the number in a seperate form though.


I created the cpaadminsundaycount variable to store the MsgBox(fileReader) number that I think is 15 so that I can use it to do the math.

Re: Input Output Function Error
 

I figured it out. It took me a really long time but here is the solution to my problem.

' Open the Sunday file for output and declare variables.
Dim filereader As System.IO.StreamReader
filereader = My.Computer.FileSystem.OpenTextFileReader("Sundaypm.txt")
Dim stringReader As String
stringReader = filereader.ReadLine()
Dim asuncount As Decimal = stringReader

Dim cpaMaxDecimal As Decimal
Dim countaDecimal As Decimal
countaDecimal = asuncount - cpaTextBox.Text
cpaMaxDecimal = cpaTextBox.Text - asuncount


' Calculate Team A situation.
If cpaTextBox.Text < asuncount Then
messageString = "Team A is understaffed by " & countaDecimal & " player(s)."
.cparesponse = messageString
Else : .cparesponse = ""
End If
If cpaTextBox.Text > asuncount Then
messageString2 = ""
.cparesponse = messageString2
messageString3 = "You have " & cpaMaxDecimal & " player(s) available from Team A."
.cparecommendation = messageString3
Else : .cparecommendation = ""

End If