TList.Count Property

Indicates the number of entries in the list that are in use.

Pascal

property Count: Integer;

C++

__property int Count;

Description

Read Count to determine the number of entries in the Items array.

Increasing the size of Count will add the necessary number of nil (Delphi) or NULL (C++) pointers to the end of the Items array. Decreasing the size of Count will remove the necessary number of entries from the end of the Items array.

Count is not always the same as the number of objects referenced in the list. Some of the entries in the Items array may contain nil (Delphi) or NULL (C++) pointers. To remove the nil (Delphi) or NULL (C++) pointers and set Count to the number of entries that contain references to objects, call the Pack method.

C++ Examples:

Copy Code

/*
This example creates a list object and inserts two records
into it. The value of the record fields are written on a
paintbox:
*/

typedef struct AList
{
  int I;
  char C;
} TAList;

typedef TAList* PAList;

void __fastcall TForm1::Button1Click(TObject *Sender)
{
  PAList AStruct;
  TList *MyList = new TList;
  // fill the TList
  AStruct = new TAList;
  AStruct->I = 100;
  AStruct->C = 'Z';
  MyList->Add(AStruct);
  AStruct = new TAList;
  AStruct->I = 200;
  AStruct->C = 'X';
  MyList->Add(AStruct);
  
  // Go through the list, writing the elements to the
  // canvas of a paintbox component.
  int Y = 10; // position on canvas
  for (int i = 0; i < MyList->Count; i++)
  {
    AStruct = (PAList) MyList->Items[i];
    PaintBox1->Canvas->TextOut(10, Y, IntToStr(AStruct->I));
    Y += 30;  // Increment Y Value again
    PaintBox1->Canvas->TextOut(10, Y, AStruct->C);
    Y += 30;  //Increment Y Value
  }

  // Clean up - must free memory for the items as well as the list
  for (int i = 0; i < MyList->Count; i++)
  {
    AStruct = (PAList) MyList->Items[i];
    delete AStruct;
  }
  delete MyList;

}

Delphi Examples:

Copy Code

{
This example creates a list object and inserts two records
into it. The value of the record fields are written on a
paintbox:
} 
procedure TForm1.Button1Click(Sender: TObject);
type
  PMyList = ^AList;
  AList = record
    I: Integer;
    C: Char;
  end;
var
  MyList: TList;
  ARecord: PMyList;
  B: Byte;
  Y: Word;
begin
  MyList := TList.Create;
  try
    New(ARecord);
    ARecord^.I := 100;
    ARecord^.C := 'Z';
    MyList.Add(ARecord); {Add integer 100 and character Z to list}
    New(ARecord);
    ARecord^.I := 200;
    ARecord^.C := 'X';
    MyList.Add(ARecord); {Add integer 200 and character X to list}

    { Now paint the items onto the paintbox}
    Y := 10;             {Variable used in TextOut function}
    for B := 0 to (MyList.Count - 1) do
    begin
      ARecord := MyList.Items[B];
      Canvas.TextOut(10, Y, IntToStr(ARecord^.I)); {Display I}
      Y := Y + 30;  {Increment Y Value again}
      Canvas.TextOut(10, Y, ARecord^.C);  {Display C}
      Y := Y + 30;  {Increment Y Value}
    end;

    { Cleanup: must free the list items as well as the list }
   for B := 0 to (MyList.Count - 1) do
   begin
     ARecord := MyList.Items[B];
     Dispose(ARecord);
   end;
  finally
    MyList.Free;
  end;
end;