Code for Add and/or Append a row in GridView C#

Hii members,

 

In my application's form there is a DropDownList and a DataGridView. I select items from the DDL and the same adds into DGV and I save it to the DB. Later, if I want to edit the DVG list, I need to delete some items and add some items or just add to existing items. When I try to do this, the system show error, 'Object reference not set to an instance of an object.'

 

Here is my code...

 

if (dgvAdvice.Rows.Count > 0)
{
DataTable dt = dgvAdvice.DataSource as DataTable;
dt.Rows.Add(cmbAdvice.SelectedText);

dgvAdvice.Columns[0].Width = 300;
}
else
{
dgvAdvice.ColumnCount = 1;
dgvAdvice.Rows.Add(cmbAdvice.Text);

dgvAdvice.Columns[0].Width = 300;
} 

 

I want to add code in DDL's Key_Up event like this...

 

Please note that if there is already rows exist in DGV, I can append rows and save IN EDIT MODE but, If I add new row in edit mode only one row adds and when try to add second row, it shows the error mentioned above.

 

Also note that I work in C# Windows Application with MS Access as db.

 

Thanks

 

Mayank Jani.