datagridview checkbox column value

Chinthaka Bandara

I have this problem.i tried many ways.but i couldn't find a solutin for my problem

I have a datagridview with a checkbox column.i want to check whether checkbox is checked or not.

 private void btn_Generate_Click(object sender, EventArgs e)
        {
            for (int i = 0; i < dataGridView1.Rows.Count-1; i++)
            {
                string values = dataGridView1.Rows[i].Cells[4].Value.ToString();
                MessageBox.Show(values);
            }
        }

if the checkbox is selected it will output as "True" in messagebox.but if checkbox is not selected it is giving me an error

"Object reference not set to an instance of an object."

i want to get output when checkbox is not checked also

please help me....
Thank you..................

4 Replies

Know the answer? Post it — somebody with the same question will find it here.

DRISHTY16y ago
Accepted answer
HEllo,
Try this..
for (int i = 0; i < dataGridView1.Rows.Count - 1; i++)
{
if (Convert.ToBoolean(dataGridView1.Rows[i].Cells[0].Value) == true)
{
string values = dataGridView1.Rows[i].Cells[1].Value.ToString();
MessageBox.Show("checked");
}
else
{
string values = dataGridView1.Rows[i].Cells[1].Value.ToString();
MessageBox.Show("unchecked");
}

}
Chinthaka Bandara16y ago
THANK YOU VERY MUCH.
IT WORKED!!!!
Chinthaka Bandara16y ago
Thank you DRISHTY
but your code didn't solve my error.it is giving me the same error :(
DRISHTY16y ago
Hi,
try this,
private void btn_Generate_Click(object sender, EventArgs e)
{
for (int i = 0; i < dataGridView1.Rows.Count-1; i++)
{
  if(dataGridView1.Rows[i].Cells[4].Value==True)
  {
   Messtring values = dataGridView1.Rows[i].Cells[4].Value.ToString();
   MessageBox.Show(values);
   sageBox.Show(values);
  }
  else
  {

  }
}
}