How to cast Null object.

How to cast Null object.

• Heidi

  I made one more change to my DbUtility class - maked the method as public. I also marked it as an answer, as I assume it is.

  cheers back at ya!

  
  
  

• Qwonfu

  Hi Blair,

  Thanks again.

  if I am using with second option of your above example, having following error:

  "The as operator must be used with a reference type ('int' is a value type) ".
  

  Regards

  
  

• Dmitry Titov MSFT

  I am thinking you can make a globally available static method:

  public static class DbUtility
  {
      static public object ValueToDefault(object value, object defaultValue) 
      { 
          return value == DBNull.Value defaultValue : value; 
      }
  }
   
  int iNotNullable = (int) DbUtility.ValueToDefault(dsTrims.Tables[0].Rows[ i ]["model_id"], int.MinValue);
  int iNullable = (int ) DbUtility.ValueToDefault(dsTrims.Tables[0].Rows[ i ]["model_id"], null);

  
  
  

• John7

  int iNotNullable = (int) dsTrims.Tables[0].Rows[ i ]["model_id"] == DBNull.Value
  int.MinValue : dsTrims.Tables[0].Rows[ i ]["model_id"];

  But see the post I just made above. .. I have made a couple of edits in it. . . make sure you get it now with my latest edits.

  
  
  

• Silvia Elena

  take a look at nullable types -

  int iNullable;
  int iNotNullable = 0;
  object obj = null;
  iNullable = obj as int ;
  if (obj is int)
  iNotNullable = (int)o;

  
  
  

• Hoot

  Thank you very much Blair,

  You are too good. I cant express my feeling.

  Have a great time.

  Cheers.....

  
  

• SameerM

  Ow Nullable types true. I forgot them sorry... :)

  Happy coding...

  
  

• Phillb

  Hi Blair,

  I am not getting about int .

  Actuallu I am getting error while using dataset as following:

  for(i=0...............{

  int intModelId = (int)dsTrims.Tables[0].Rows[ i ]["model_id"]; }

  where "dsTrims" is dataset.

  In this code if "model_id" is null then getting error that "casting is not valid".

  How can I solve this error without writing lots of code. I can do it by checking like:

  if(dsTrims.Tables[0].Rows[ i ]["model_id"] is DBNULL){ ....... }

  But I have to write/check this statement for each & every column.

  Any other possible way

  Thank you

  
  

• Coolnet1savvy

  int iNullable = (dsTrims.Tables[0].Rows[ i ]["model_id"] == DBNull.Value
  null : dsTrims.Tables[0].Rows[ i ]["model_id"]) as int ;

  int is a Nullable Integer

  or, if non-nullable int and want DBNull to be int.MinValue:

  int iNotNullable = (dsTrims.Tables[0].Rows[ i ]["model_id"] == DBNull.Value
  int.MinValue : dsTrims.Tables[0].Rows[ i ]["model_id"]) as int;

  
  
  

• Grahamrounce

  Hello, Null casting is invalid in .NET Because null objects doesn't has a memory area. No start point. No length. It is impossible. Happy coding...
  
• How to cast Null object.