控件类型问题

[Harrison_2009]

for (int i = 0; i < pnl.Controls.Count; i++) //pnl 的类型是DevExpress.XtraEditors.XtraScrollableControl
{
var temptype = pnl.Controls[i].GetType();
我想实现的效果是：
if(temptype == type(DevExpress.XtraEditors.TextEdit))
{
((DevExpress.XtraEditors.TextEdit)pnl.Controls[i]).Properties.ReadOnly = ...;
continue;
}
if(temptype == type(DevExpress.XtraEditors.LookUpEdit))
{
((DevExpress.XtraEditors.LookUpEdit)pnl.Controls[i]).Properties.ReadOnly = ...;
continue;
}...
}

不过因为类型太多了而我不想写那么多只想写成：

for (int i = 0; i < pnl.Controls.Count; i++) //pnl 的类型是DevExpress.XtraEditors.XtraScrollableControl
{
var temptype = pnl.Controls[i].GetType();
((temptype)pnl.Controls[i]).Properties.ReadOnly = ...;
continue;
}

求救各位大虾，我应该如何处理？