Can I get the control of an object just knowing its name?
If you're asking what I think you're asking, no.
Why: Setting the value of a.Name doesn't have anything to do with what type of control it is. a as ComboBox will always return null because here, a is only a Control .
If a is assigned a value that is acutally a ComboBox , then a as ComboBox will be able to get you the actual ComboBox object. Assuming you have a member of the form named comboBox1 , this might be what you want:
a = comboBox1;
ComboBox combo = a as ComboBox;
But in that case, it's easier just use comboBox1 directly.