DELPHI6 in DSGNINTF.DCU solution can not be found at

https://www.cnblogs.com/gaodu2003/archive/2009/06/04/1495789.html

1, add lib \ requires designide.dcp to control dpk file section
2, in the pas control's source file usually uses dsgnintf place into
    uses DesignIntf, DesignEditors 
3, to join the search path 
   X: \ Program Files \ Borland \ Delphi6 \ the Source \ ToolsAPI 
   [X-letter is located Delphi6]
4, the file "DesignEditors.pas" in, Proxies implementation hidden away portion 
    uses DesignConst, Consts, RTLConsts, Contnrs {,} the Proxies; 
. 5, and to find 
    while IsProxyClass ( ComponentClass) do 
    change 
    // the while IsProxyClass (ComponentClass) do 
6, save, compile and run, OK 

1, add lib \ requires designide.dcp to control dpk file section
2, in the pas control's source file usually uses dsgnintf place into
    uses DesignIntf, DesignEditors 
3, to join the search path 
   X: \ Program Files \ Borland \ Delphi6 \ the Source \ ToolsAPI 
   [X-letter is located Delphi6]
4, the file "DesignEditors.pas" in, Proxies implementation hidden away portion 
    uses DesignConst, Consts, RTLConsts, Contnrs {,} the Proxies; 
. 5, and to find 
    while IsProxyClass ( ComponentClass) do 
    change 
    // the while IsProxyClass (ComponentClass) do 
6, save, compile and run, OK