form variables

i want to write a for each loop that will go through each control in a form and place the value of that control in a string
something like this
 
foreach (string s in form1.ID.ToString())
{
str += form1.ID.ToString();
}  
Firstly,
I dont know if form1.ID will give me what i want and secondly there is an issue with char and string convert that i can't workout
 
Can anyone help out here?
 
 

...