416 ?

.       , .
    .

      TEdit    
 TEditLetNum.  ,  ,   TEdit, -
    : EnableNum  EnableLet.    
bool.        ,     ,
  - ,  .  ,  Enable- '
Num = true  EnableLet = true,      . 
EnableNum = true, a EnableLet = false,  ,    
 .  EnableNum = false, a EnableLet = true,   , 
 .   ,  EnableNum = false  EnableLet = false, 
,       .

    Clear       
Modified,   ,       -
 .       OnClear.

  ,        -
     ,     - '
.        5.1.2.4  5.

  C++Builder   . ,    
 ,       ,  
    (,     ).   
:

1.   File | New     New Items   New
  Package  .       -
  (Package Manager),   . 7.3.    Contains
  , a Requires    ,  
 .

2.        .dpk,  
File | Save As    Save  ,    -
  .

3.    Add (),    ,  
    (Add Unit),  (New Component)  Activr
(Import ActiveX).           :

.      ,  
,   . 7.4.       (:

 TEdit    Ancestor type),     ;

Class Name (    TEditLetNum),   ';

 (Palete Page),      
 .        . ;

         ( Unit
name).

. 7.3

   , 
   