Question

hey guys, i’m getting an exception on the following

inner exception: {‘Value cannot be null.\r\nParameter name: String’}

Which reads like a simple error message, but none of the values (image, fileName) are null. How can i find out where this null String is?

RipHelper.UploadImage(image, fileName); 

which calls

public static void UploadImage(System.Drawing.Image image, string fileName)         { // this line is never reached          } 

Here is the full error log

#

System.ArgumentNullException: Value cannot be null. Parameter name: String at System.Number.StringToNumber(String str, NumberStyles options, NumberBuffer& number, NumberFormatInfo info, Boolean parseDecimal) at System.Number.ParseInt32(String s, NumberStyles style, NumberFormatInfo info) at System.Int32.Parse(String s) at Helpers.RipHelper..cctor() in C:\Helpers\RipHelper.cs:line 23 — End of inner exception stack trace — at Helpers.RipHelper.UploadImage(HttpPostedFile uploadFile, String fileName) at Helpers.UploadHelper.UploadImage(HttpContext context) in C:\Helpers\UploadHelper.cs:line 79

Answer 1

The exception is in the static constructor of the class Helpers.RipHelper, at line 23 of RipHelper.cs. This line is calling Int32.Parse, passing a null value.

Perhaps the static constructor is referencing a static field that has not yet been initialized. If you are having trouble debugging this, post the code of the class including the static constructor and any field initializers.