Problem in null conversion?

Question

Hello Friends I m new in C# programming. when i access data from a file. i don't know each field has data or not. but in my c# coding file wirte code double value=Convert.ToDouble(dataRow[fieldValue]); if fieldValue is null or empty this code show exception. Please suggest. Thanks.

Jitendra Tiwari · Answer

excelUserRecord = (from abc in dataRow where (listSchemeCode.Contains(abc.Field (ProductCode))) || (listTrnxNo.Contains(Convert.ToString((abc.Field ( TransactionNo ))))) || (listFolioNo.Contains((abc.Field (FolioNo)))) select abc); there is no prob field value is double or string. problem is that if the value of TransactionNO(Bold in code block) is null linq query throw exception. when I access each row from data row collection

Sam Hobbs · Answer

In your original question you said the field is a double but in your last post you show a string field so which is it?

Jitendra Tiwari · Answer

hello Amit thanks but my problem like this excelUserRecord = (from abc in dataRow where (listSchemeCode.Contains(abc.Field (ProductCode))) || (listTrnxNo.Contains(Convert.ToString((abc.Field (TransactionNo))))) || (listFolioNo.Contains((abc.Field (FolioNo)))) select abc); if transaction is null form show errorrrr

Amit Choudhary · Answer

hi friend put a condition before using the value: if(dataRow[fieldValur]!=DBnull) { double value=Convert.ToDouble(dataRow[fieldValue]); } please mark as answer if it helps.

Hirendra Sisodiya · Answer

you can use this code : if (dataRow[ fieldValue ] != null ) { double value = Convert .ToDouble(dataRow[ fieldValue ]); } else { } thanks Please Check answere if you like my answere