I've updated your example.
With AutoSize = true, if you set the Anchor property to include AnchorStyles.Right then .Height (and .Bottom) are broken.
With AutoSize = false, if you set the Anchor property to include AnchorStyles.Right then .Height (and .Bottom) are perfect.
I've changed my current solution to set AutoSize to false so I can
properly evaluate the values (since I do the layout calculations last
and all setting, including anchors, is done first). An alternative would
be to always set anchors last.
I cannot attach anything other than images but if you change the click handler to this snippet you will achieve the same behaviour.
01.privatevoidradButton1_Click(objectsender, EventArgs e)02. {03. RadDropDownList ddl = newRadDropDownList();04. //ddl.AutoSize = false;05. ddl.Anchor = AnchorStyles.Left | AnchorStyles.Top | AnchorStyles.Right;06. this.splitPanel1.Controls.Add(ddl);07. 08. if(ddl.Height == 0) MessageBox.Show(String.Format("AH! This isn't good! Bottom: {0}, Height: {1}", ddl.Bottom, ddl.Height));09. 10. RadDropDownList ddl2 = newRadDropDownList();11. ddl2.Top = ddl.Bottom + 6;12. this.splitPanel1.Controls.Add(ddl2);13. }