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

Apparently your dt.Rows(0)("SupEmail") is coming as NULL from DB and you cannot assign NULL to string property. Try replacing that line with:

hfSupEmail.Value = If(IsDbNull(dt.Rows(0)("SupEmail")), String.Empty, dt.Rows(0)("SupEmail").ToString)

The code checks if value is NULL and if it is - replaces it with empty string, otherwise uses original value.