title: Delete multiple rows in datagridview
body: <p>I have a function to delete single rows on right click delete in a datagridview..</p>
  
  <p>code:</p>
  
  <pre><code>  private void dataGridView1_MouseDown(object sender, MouseEventArgs e)
      {
  
              if (e.Button == MouseButtons.Right)
              {
                  var hti = dataGridView1.HitTest(e.X, e.Y);
                  if (hti.RowIndex != -1)
                  {
                      dataGridView1.ClearSelection();
                      dataGridView1.Rows[hti.RowIndex].Selected = true;
                  }
              }          
      }
  
      private void DeleteRow_Click(object sender, EventArgs e)
      {
              Int32 rowToDelete = dataGridView1.Rows.GetFirstRow(DataGridViewElementStates.Selected);
              if (rowToDelete != -1)
              {
                  dataGridView1.Rows.RemoveAt(rowToDelete);
                  dataGridView1.ClearSelection();
              }          
      }
  </code></pre>
  
  <p>but now I want to delete multiple rows on selection.<br>
  First I don't know why I cannot select multiple rows.<br>
  Second I want to delete multiple delete using the delete button and right click mouse delete.</p>
  
  <p>Can someone help me?</p>