Получить доступ к элементам списка с помощью API

Оформил: DeeCo

{ 
  This code might be useful for nonVCL applications or to read Listbox 
  items from another application. 
}

 { 
  Die folgenden Funktionen konnen z.B fur nonVCL Projekte verwendet werden 
  oder auch zum Auslesen von Listboxen aus anderen Applikationen. 
}


 // Retrieve the number of items in a ListBox 
// Anzahl Eintrage einer ListBox ermitteln 

function LB_GetItemCount(hListBox: THandle): Integer;
 begin
   Result := SendMessage(hListBox, LB_GETCOUNT, 0, 0);
 end;

 // Delete a string in a ListBox 
// Einen String in einer ListBox loschen 

procedure LB_DeleteItem(hListBox: THandle; Index: Integer);
 begin
   SendMessage(hListBox, LB_DELETESTRING, Index, 0);
 end;

 // Retrieve the selected item from a ListBox 
// Gibt den Text des markiertes Items einer ListBox zuruck 

function LB_GetSelectedItem(hListBox: THandle): string;
 var
   Index, len: Integer;
   s: string;
   buffer: PChar;
 begin
   Index := SendMessage(hListBox, LB_GETCURSEL, 0, 0);
   len := SendMessage(hListBox, LB_GETTEXTLEN, wParam(Index), 0);
   GetMem(buffer, len + 1);
   SendMessage(hListBox, LB_GETTEXT, wParam(Index), lParam(buffer));
   SetString(s, buffer, len);
   FreeMem(buffer);
   Result := IntToStr(Index) + ' : ' + s;
 end;

 // Example, Beispiel: 

procedure TForm1.Button1Click(Sender: TObject);
 var
   hListBox: THandle;
 begin
   hListBox := {...}; // listbox handle 
  ListBox1.Items.Text := LB_GetSelectedItem(hListBox);
 end;

 // Retrieve a string from a ListBox 
// Gibt den Text eines bestimmten Items einer ListBox zuruck 

function LB_GetListBoxItem(hWnd: Hwnd; LbItem: Integer): string;
 var
   l: Integer;
   buffer: PChar;
 begin
   l := SendMessage(hWnd, LB_GETTEXTLEN, LbItem, 0);
   GetMem(buffer, l + 1);
   SendMessage(hWnd, LB_GETTEXT, LbItem, Integer(buffer));
   Result := StrPas(buffer);
   FreeMem(buffer);
 end;

 // Example, Beispiel: 

procedure TForm1.Button2Click(Sender: TObject);
 var
   hListBox: THandle;
 begin
   hListBox := {...}; // listbox handle 
  ListBox1.Items.Text := LB_GetListBoxItem(hListBox, 2);
 end;

 // Gibt den gesamten Text einer ListBox zuruck 
// Retrieve all listbox items 

function LB_GetAllItems(hWnd: Hwnd; sl: TStrings): string;
 var
   RetBuffer: string;
   i, x, y: Integer;
 begin
   x := SendMessage(hWnd, LB_GETCOUNT, 0, 0);
   for i := 0 to x - 1 do
   begin
     y := SendMessage(hWnd, LB_GETTEXTLEN, i, 0);
     SetLength(RetBuffer, y);
     SendMessage(hWnd, LB_GETTEXT, i, lParam(PChar(RetBuffer)));
     sl.Add(RetBuffer);
   end;
 end;

 // Example, Beispiel: 

procedure TForm1.Button3Click(Sender: TObject);
 var
   sl: TStringList;
   ListBox_Handle: THandle;
 begin
   hListBox := {...}; // listbox handle 
  sl := TStringList.Create;
   try
     LB_GetAllItems(ListBox_Handle, sl);
   finally
     ListBox1.Items.Text := sl.Text;
     sl.Free;
   end;
 end;