Getting this error
can any one please help me

Error : Cast from type 'DBNull' to type 'String' is not valid.

Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.InvalidCastException: Cast from type 'DBNull' to type 'String' is not valid.

Source Error:


Line 83: Dim tcellcoldata As New TableCell
Line 84: 'a = EmptyIf(New LiteralControl(dr(dc.ColumnName.ToString)))
Line 85: tcellcoldata.Controls.Add(New LiteralControl(dr(dc.ColumnName.ToString)))
Line 86: 'tcellcoldata.Controls.Add()
Line 87: trow.Cells.Add(tcellcoldata)

You cant convert a NULL to a string.

dc.ColumnName is likely Null.

If you step through you can check the value during the run.

Hal Levy
Web Developer, PDI Inc.

NOT a Wiley/Wrox Employee

can u help me how to rectify this error and make changes to the code

You rectify the error by making your data non-null.

Hal Levy
Web Developer, PDI Inc.

NOT a Wiley/Wrox Employee

Alternatively, you can check for a null value in your Code behind file:

If dr(dc.ColumnName) is DbNull.Value Then

Not sure if it will work like this because I don't know what dr and dc are, but generally comparing against DbNull.Value will do the trick.

Cheers,

Imar
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Imar Spaanjaars
Everyone is unique, except for me.