Question

When an exception is thrown (while debugging in the IDE), i have the opportunity to view details of the exception:

But in code if i call exception.ToString() i do not get to see those useful details:

System.Data.SqlClient.SqlException (0x80131904): Could not find stored procedure 'FetchActiveUsers'.
  [...snip stack trace...]

But Visual Studio has some magic where it can copy the exception to the clipboard:

Which gives the useful details:

System.Data.SqlClient.SqlException was unhandled by user code
  Message=Could not find stored procedure 'FetchActiveUsers'.
  Source=.Net SqlClient Data Provider
  ErrorCode=-2146232060
  Class=16
  LineNumber=1
  Number=2812
  Procedure=""
  Server=vader
  State=62
  StackTrace:
       [...snip stack trace...]
  InnerException:

Well i want that!

What would be the contents of:

String ExceptionToString(Exception ex)
{ 
    //todo: Write useful routine
    return ex.ToString();
}

that can accomplish the same magic. Is there a .NET function built in somewhere? Does Exception have a secret method somewhere to convert it to a string?

Answer 1

ErrorCode is specific to ExternalException, not Exception and LineNumber and Number are specific to SqlException, not Exception. Therefore, the only way to get these properties from a general extension method on Exception is to use reflection to iterate over all of the public properties.

So you’ll have to say something like:

public static string GetExceptionDetails(this Exception exception) {
    var properties = exception.GetType()
                            .GetProperties();
    var fields = properties
                     .Select(property => new { 
                         Name = property.Name,
                         Value = property.GetValue(exception, null)
                     })
                     .Select(x => String.Format(
                         "{0} = {1}",
                         x.Name,
                         x.Value != null ? x.Value.ToString() : String.Empty
                     ));
    return String.Join("\n", fields);
}

(Not tested for compliation issues.)

.NET 2.0 compatible answer:

public static string GetExceptionDetails(this Exception exception) 
{
    PropertyInfo[] properties = exception.GetType()
                            .GetProperties();
    List<string> fields = new List<string>();
    foreach(PropertyInfo property in properties) {
        object value = property.GetValue(exception, null);
        fields.Add(String.Format(
                         "{0} = {1}",
                         property.Name,
                         value != null ? value.ToString() : String.Empty
        ));    
    }         
    return String.Join("\n", fields.ToArray());
}