public void TestTableLayoutStyleOwned () { try { ColumnStyle style = new ColumnStyle (); TableLayoutColumnStyleCollection coll = new TableLayoutPanel ().ColumnStyles; coll.Add (style); TableLayoutColumnStyleCollection coll2 = new TableLayoutPanel ().ColumnStyles; coll2.Add (style); Assert.Fail ("#1"); } catch (ArgumentException ex) { // PASS } try { RowStyle style = new RowStyle (); TableLayoutRowStyleCollection coll = new TableLayoutPanel ().RowStyles; coll.Add (style); TableLayoutRowStyleCollection coll2 = new TableLayoutPanel ().RowStyles; coll2.Add (style); Assert.Fail ("#2"); } catch (ArgumentException ex) { // PASS } }