Is there anything wrong with this line of code?

Question

I have this line of code in a method I'm writing:

 Dictionary<string, object> fieldsVal = file.ListItemAllFields.FieldValues;
 if (fieldsVal.ContainsKey(System.Xml.XmlConvert.EncodeName("State0")) && fieldsVal[System.Xml.XmlConvert.EncodeName("State0")].ToString() == "12 final approvement" && (extension == 
".csv" || extension == ".jpg" || extension == ".png" || extension == "xlsx"))

I get a System.NullReferenceException in the line where the if statement starts and I don't understand why.

Answer 1

Perhaps the fieldsVal[System.Xml.XmlConvert.EncodeName("State0")] contains an empty (null) value and then it can not convert it to a string.

Try to always have a valid string without checking for null:

Dictionary<string, object> fieldsVal = file.ListItemAllFields.FieldValues;
 if (fieldsVal.ContainsKey(System.Xml.XmlConvert.EncodeName("State0")) && (fieldsVal[System.Xml.XmlConvert.EncodeName("State0")] + "") == "12 final approvement" && (extension == 
".csv" || extension == ".jpg" || extension == ".png" || extension == "xlsx"))