Conversion from type 'DBNull' to type 'String' is not valid

Question

i am receiving this problem

Conversion from type \'DBNull\' to type \'String\' is not valid.

Line 501: hfSupEmail.

Answer 1

To handle it from code, here is a small extension method

Imports Microsoft.VisualBasic
Imports System.Runtime.CompilerServices

Public Module HTMLExtensionMethods
     _
    Public Function DefaultIfDBNull(Of T)(ByVal obj As Object) As T
        Return If(Convert.IsDBNull(obj), CType(Nothing, T), CType(obj, T))
    End Function
End Module

Call it like this.

hfSupEmail.Value = dt.Rows(0)("SupEmail").DefaultIfDBNull(Of String)()