Delphi SendMessage of string

This is how you sendmessage a string passing it either WParam or LParam.

procedure MySenderFunction;
var
 sText: String;   
begin
    sText := 'This is a test'.
     SendMessage(Handle, WM_MYMESSAGE, Integer(@sText), 0) ;
end;


This is how you get the parameter being passed.

procedure MySenderFunction(Msg: TMessage);
var
    sText: String;
begin
    sText := PString(Msg.WParam)^;
end;

Delphi Stream to String

String grid filter

procedure MyFilter(AFilter: String);
begin
   grid.Filter.Clear;
  with grid.Filter.Add do
  begin
    Condition:=AFilter;
    Column:=1;
  end;

  grid.FilterActive:=active;
end;

Checking if a folder is empty.

function IsDirectoryEmpty(const ADirectory: String): Boolean;
var
  searchRec: TSearchRec;
begin
   try

Result := (FindFirst(ADirectory+'\*.*', faAnyFile, searchRec) = 0) AND
  (FindNext(searchRec) = 0) AND
  (FindNext(searchRec) <> 0);

   finally
     FindClose(searchRec);
   end;
end;

Block Alt-F4 in Delphi

procedure TForm1.FormKeyDown(Sender: TObject; var Key: Word; Shift: TShiftState);
begin
  if (Key = VK_F4) and (ssAlt in Shift) then
       Key := 0;
end;

How to Minimize All Windows

uses ComObj;

procedure MinimizeAll;
var
  Shell : OleVariant;
begin
  try
   Shell := CreateOleObject('Shell.Application') ;
   Shell.MinimizeAll;
  finally
  end;
end;