title: DataGridView.SelectedRows.Count always = 0
body: <p>I have a datagridview in my application.  I want to be able to select one or more rows, then right mouse click and get a context menu.  Options in the context menu will do something with the selected rows, like hide them for example.  For the datagridview, I have multiselect=true and selectionmode=fullrowselect.  For some reason, the datagridview.selectedrows.count is always = 0.  Why might this be?  Here is code...</p>
  
  <pre><code> private void Form1_Load(object sender, EventArgs e)
      {
          Image img = null;
          contextMenuStrip1.Items.Add("Hide selected", img, new System.EventHandler(contextMenuStrip1_Click));
          contextMenuStrip1.Items.Add("Unhide all", img, new System.EventHandler(contextMenuStrip1_Click));
          dataGridView1.ContextMenuStrip = contextMenuStrip1;
      }   
  
     private void contextMenuStrip1_Click(object sender, EventArgs e)
      {
          switch (sender.ToString().Trim())
          {
              case "Hide selected":
                  //Necessary because a row with the current cell cannot be hidden.
                  dataGridView1.CurrentCell = null;
                  int count = dataGridView1.SelectedRows.Count;
                  foreach (DataGridViewRow row in dataGridView1.SelectedRows)
                  {
                      row.Visible = false;
                  }
                  break;
  
              case "Unhide all":
                  foreach (DataGridViewRow row in dataGridView1.Rows)
                  {
                      row.Visible = true;
                  }
                  break;
          }
  
      }
  </code></pre>