CODEWITHSUNDEEP
vb.net.net
webworm
webworm

Reputation: 11019

Invalid Cast Exception. Not sure why

Can anyone see from the following function why I would be getting an "Invalid Cast Exception"? More specifically this is the error "Conversion from string "yyyyMMdd" to type 'Integer' is not valid."

I am trying to convert a DateTime value from the database to a String with the format "yyyyMMdd" so for example October 22, 1985 would be "19851022".

dbReader(fieldName).ToString("yyyyMMdd")

Here is the entire function ...

Private Function GetDBReaderDateValue(ByVal dbReader As IDataReader, ByVal fieldName As String) As String

    If dbReader(fieldName) Is DBNull.Value Then
        Return ""
    Else
        Return dbReader(fieldName).ToString("yyyyMMdd")
    End If

End Function

Upvotes: 1

Views: 2157

Answers (2)

Tim Schmelter
Tim Schmelter

Reputation: 460288

If fieldName is not a DateTime, conversion will fail. Try to cast it to a Datetime first:

Dim dt As Date
If Date.TryParse(dbReader(fieldName).tostring, dt) Then
     Return dt.ToString("yyyyMMdd")
Else
     Throw New ArgumentException("GetDBReaderDateValue needs a Date-Column as parameter!")
End If

Upvotes: 1

user541686
user541686

Reputation: 210755

It seems like you're calling ToString on an Object... and there's no overload that takes a String parameter. You probably need to cast to a DateTime first.

Upvotes: 1

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