send data to another program by auto-drag&drop?

下面的代码演示给记事本用拖放的方式打开一个文件。

uses

 ShellAPI ;

function MakeDrop ( const FileNames : array of string ): THandle ;

// Creates a hDrop Object

var

 I , Size : Integer ;

 Data : PDragInfoA ;

 P : PChar ;

begin

  // Calculate memory size needed

 Size := SizeOf ( TDragInfoA ) + 1 ;

  for I := 0 to High ( FileNames ) do

   Inc ( Size , Length ( FileNames [ I ]) + 1 );

  // allocate the memory

 Result := GlobalAlloc ( GHND or GMEM_SHARE , Size );

  if Result <> 0 then

  begin

   Data := GlobalLock ( Result );

    if Data <> nil then

      try

        // fill up with data

       Data . uSize := SizeOf ( TDragInfoA );

       P   := PChar (@ Data . grfKeyState ) + 4 ;

       Data . lpFileList := P ;

        // filenames at the at of the header (separated with #0)

        for I := 0 to High ( FileNames ) do

        begin

         Size := Length ( FileNames [ I ]);

         Move ( Pointer ( FileNames [ I ])^, P ^, Size );

         Inc ( P , Size + 1 );

        end ;

      finally

       GlobalUnlock ( Result );

      end

    else

    begin

     GlobalFree ( Result );

     Result := 0 ;

    end ;

  end ;

end ;

function MyEnum ( Wnd : hWnd ; Res : PInteger ): Bool ; stdcall ;

// search for a edit control with classname 'TEditControl'

var

 N : string ;

begin

 SetLength ( N , MAX_PATH );

 SetLength ( N , GetClassName ( Wnd , Pointer ( N ), Length ( N )));

 Result := AnsiCompareText ( 'TEditControl' , N ) <> 0 ;

  if not Result then Res ^ := Wnd ;

end ;

// Example: Open msdos.sys in Delphi's Editor window

procedure TForm1 . Button1Click ( Sender : TObject );

var

 Wnd : HWnd ;

 Drop : hDrop ;

begin

  // search for Delphi's Editor

//  EnumChildWindows(FindWindow('TEditWindow', nil), @MyEnum, Integer(@Wnd));

 wnd := FindWindow ( 'notepad' , nil );

  if IsWindow ( Wnd ) then

  begin

    // Delphi's Editor found. Open msdos.sys

   Drop := MakeDrop ([ ' C :\msdos.sys' ]);

    if Drop <> 0 then PostMessage ( Wnd , wm_DropFiles , Drop , 0 );

    // Free the memory?

   GlobalFree ( Drop );

  end ;

end ;