Error NullReferenceException was unhandled in C# Windows Application

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I am beginner in C# Windows Application.
I am saving data in sql server 2005.
I have a decimal column namely origrate in table.
I am picking data from datagridview cell.
To save data in table I convert type of datagridview cell value to decimal.
as like :

C#

decimal iorigrate=0M;
if(!string.IsNullOrEmpty(dataGridView1.Rows[i].Cells["origrate"].Value.ToString()))
   iorigrate =Convert.ToDecimal(dataGridView1.Rows[i].Cells["origrate"].Value);

but I have following errors

C#

NullReferenceException was unhandled

Kindly tell me where I am wrong.

Please help me.

Posted 6-Dec-11 15:30pm

Manoj Dua

Updated 6-Dec-11 15:36pm

D K N T H

v2

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D K N T H 6-Dec-11 21:37pm

added pre tag

3 solutions

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Abhinav S · Answer 1 · 2011-12-06T16:09:00

You are converting dataGridView1.Rows[i].Cells["origrate"].Value to string by using ToString().
If the value is null, this will fail with the error you are getting.

Try checking for null before you apply ToString().
Debugging and stepping through code will give you an idea when you are getting this error.

Eduard Lu · Answer 2 · 2011-12-06T17:26:00

Change your code from

C#

decimal iorigrate=0M;
if(!string.IsNullOrEmpty(dataGridView1.Rows[i].Cells["origrate"].Value.ToString()))
   iorigrate =Convert.ToDecimal(dataGridView1.Rows[i].Cells["origrate"].Value);

to:

C#

decimal iorigrate=0M;
if(!string.IsNullOrEmpty(dataGridView1.Rows[i].Cells["origrate"].Value))
   iorigrate =Convert.ToDecimal(dataGridView1.Rows[i].Cells["origrate"].Value);

FYI, use Decimal.TryParse method instead, to prevent getting these kind of errors.

Here for your reference:
http://msdn.microsoft.com/en-us/library/system.decimal.tryparse.aspx[^]

Regards,
Eduard

D K N T H · Answer 3 · 2011-12-06T16:18:00

see this codes:

C#

 foreach (GridViewRow gridviewrow in grvAuction.Rows)
{
                       
  decimal iorigrate=0M;
//Cells[1] - index of desired cell
 if(!string.IsNullOrEmpty(dataGridView1.Cells[1].Text))
  {
   iorigrate =Decimal.Parse(dataGridView1.Rows[i].Cells[1].Value);

   }
}

hope it helps!

thnks

don't forget to vote:)

Error NullReferenceException was unhandled in C# Windows Application

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