-4
private void button1_Click(object sender, EventArgs e)    
{          
     richTextBox1.Clear();

     foreach (string line in richTextBox2.Lines)      
     {  

           string searchValue = line;
           searchValue = searchValue.Trim();
           dataGridView1.SelectionMode =DataGridViewSelectionMode.FullRowSelect;
            try
             {
              foreach (DataGridViewRow row in dataGridView1.Rows)
               {
                if(row.Cells[0].Value.ToString().Trim().Equals(searchValue))//error containing line
                 {
                   richTextBox1.Text += (row.Cells[1].Value.ToString().Trim()) + "\n";
                 }
               }
             }
             catch (Exception exc)
             {
                    MessageBox.Show(exc.Message);
             }
     }
}
GAMITG
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dilhan
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    Possible duplicate of [What is a NullReferenceException and how do I fix it?](http://stackoverflow.com/questions/4660142/what-is-a-nullreferenceexception-and-how-do-i-fix-it) – dotnetom Oct 19 '15 at 04:49
  • It's a common error due to `null`, Could you please tell which line is throwing the error? – sujith karivelil Oct 19 '15 at 04:50
  • if(row.Cells[0].Value.ToString().Trim().Equals(searchValue))//error containing line – dilhan Oct 19 '15 at 04:57
  • D.d.S Read the link @dotnetom gave you. – Rob Oct 19 '15 at 05:01
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    Use Convert.ToString() when you are not sure if source string will have valid value. So that even if you pass null it will not throw exception. – Nikhil Vartak Oct 19 '15 at 05:03
  • thank "dotnetkid". i done it. but error is still having.. – dilhan Oct 19 '15 at 05:11
  • thank you all of u. i solved my error. foreach (DataGridViewRow row in dataGridView1.Rows) { if(row.Cells[0].Value==null) { break; } else { if (row.Cells[0].Value.ToString().TrimStart().TrimEnd().Equals(searchValue.TrimStart().TrimEnd())) { richTextBox1.Text += (row.Cells[1].Value.ToString().TrimStart().TrimEnd()) + "\n"; – dilhan Oct 19 '15 at 11:00

1 Answers1

0

foreach (DataGridViewRow row in dataGridView1.Rows)

{

if(row.Cells[0].Value==null) {

break;

} else {

if (row.Cells[0].Value.ToString().TrimStart().TrimEnd().Equals(searchValue.TrimStar‌​t().TrimEnd()))

{ richTextBox1.Text += (row.Cells[1].Value.ToString().TrimStart().TrimEnd()) + "\n";}

dilhan
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