title: Add button to certain cell in datagridview
body: <p>I have created a Datagridview.
  Now whenever the cell contains an empty value, It will add the plus button to the cell. Something like this:</p>
  
  <pre><code>if ((string)((Hashtable)ht[i])["value"] == "")
    {
       // Create a Save button column
       DataGridViewImageButtonSaveColumn columnSave = new DataGridViewImageButtonSaveColumn();
  
       // Set column values
  
       //Add the columns to the grid6
       if (!dataGridView1.Columns.Contains("SaveButton"))
          {
             dataGridView1.Columns.Insert(5, columnSave);
          }
    }
    else
    {
       //hide save button.
    }
  </code></pre>
  
  <p>But now my problem is that it display the plus button at all cell for that column even though that particular cell have value. How can I hide the button for the cell that have value? </p>