DataGridView for loop error -

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considering following code:

public class crewdatabaseform

public shared crewlist list(of string)  private sub crewdatabaseform_formclosed(sender object, e formclosedeventargs) handles me.formclosed     dim cl new list(of string)     if datagridview1.rows.count = 2 cl.add(datagridview1.rows(0).cells(0).value)     if datagridview1.rows.count > 2         integer = 0 (datagridview1.rows.count - 2)             cl.add(datagridview1.rows(i).cells(0).value.tostring)         next     end if     messagebox.show(datagridview1.rows.count.tostring)   end sub   private sub crewdatabaseform_load(sender object, e eventargs) handles mybase.load  end sub

end class

--this form datagridview. whenever exit form, , if , statements commence, if have entered value in first column , not pressed enter error occurs:

"an exception of type 'system.nullreferenceexception' occurred in stage tally.exe not handled in user code

additional information: object reference not set instance of object.

if there handler exception, program may safely continued."


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