Read barcode scanner data in textbox but prevent from user

Question

Hi there, hope all are fine,,

 

   Today I face some difficult problem. I can read the data from a barcode scanner in textbox.  Now the problem is i have to prevent the textbox from user manual input. I have all ways like disable, read only, keycode disable,, etc..,   I have searched more things in google. but but google goes hidden in this matter....lol.. 

 Now i need to do this task... so u genius please help me to achieve this... waiting for your reply.... thanks in advance....