The followings codes I am trying to realize it are:

Firstly, instantiate a Winfrom inherited from "System.Windows.Forms.Form",
Secondly, Load background image to the Winform and override fellowing codes
to  realize transparent effect:
-------------------------------------------------------
protected override CreateParams CreateParams
{
   //set form style
   get
   {
       CreateParams cp = base.CreateParams;
       cp.ExStyle |= 0x00080000; // This form has to have the WS_EX_LAYERED
extended style
       return cp;
   }
}
-------------------------------------------------------

However, Translucence and faintness cannot be achieved by codes above,
Moreover, i am not able to add a new UserControl in that Winform.

How can i solve this problom?
I appreciate other solution as well.
Thank you very much!!!!