title: Add DataGridViewComboBoxCell to GridView c#
body: <p>Seems like it's so simple but for some reason working on it last 4 hours with no result.
  I have simple Gridview with  two columns and few rows already filled, now I want to add ComboBoxCell to the next row.</p>
  
  <p>I'll show my logic and maybe you'll show me my error:</p>
  
  <pre><code>SampleGridView.Rows.Add("test1", "test1");
  SampleGridView.Rows.Add("test2", "test2");
  SampleGridView.Rows.Add("test3", "test3");
  </code></pre>
  
  <p>works fine for three rows now I am inserting my ComboBox:</p>
  
  <pre><code>DataGridViewRow RowSample = new DataGridViewRow();
  DataGridViewComboBoxCell  CellSample = new DataGridViewComboBoxCell();
  CellSample.DataSource = StringList; // list of the items that I want to insert in ComboBox
  RowSample.Cells.Add(CellSample);
  SampleGridView.Rows.Add(RowSample);
  </code></pre>
  
  <p>Any ideas? Thank you</p>