動的配列の指定された要素を削除する方法-Splendourの質問の一部に返信します.

type
  TArr = array of TPoint; { ,   TPoint  }

{ :   arr  ,   Index  }
procedure DeleteArrItem(var arr: TArr; Index: Integer);
var
  Count: Cardinal;
begin
  Count := Length(arr);
  if (Count = 0) or (Index < 0) or (Index >= Count) then Exit;
  Move(arr[Index+1], arr[Index], (Count-Index)* SizeOf(arr[0]));
  SetLength(arr, Count - 1);
end;

{ }
procedure TForm1.Button1Click(Sender: TObject);
var
  arr: TArr;
  i: Integer;
begin
  { }
  SetLength(arr, 5);
  arr[0].X := 1; arr[0].Y := 111;
  arr[1].X := 2; arr[1].Y := 222;
  arr[2].X := 3; arr[2].Y := 333;
  arr[3].X := 4; arr[3].Y := 444;
  arr[4].X := 5; arr[4].Y := 555;

  { ,  }
  DeleteArrItem(arr, 3);
  for i := 0 to Length(arr) - 1 do
    Memo1.Lines.Add(Format('%d, %d', [arr[i].X, arr[i].Y]));
end;

 
 
 
 
 

 

 
  

type
  TArr = array of TPoint;
  PArr = ^TArr;

{ }
procedure DeleteArrItem(p: PArr; Index: Integer);
var
  Count: Cardinal;
begin
  Count := Length(p^);
  if (Count = 0) or (Index < 0) or (Index >= Count) then Exit;
  Move(p^[Index+1], p^[Index], (Count-Index)* SizeOf(p^[0]));
  SetLength(p^, Count - 1);
end;

{ }
procedure TForm1.Button1Click(Sender: TObject);
var
  arr: TArr;
  i: Integer;
begin
  SetLength(arr, 5);
  arr[0].X := 1; arr[0].Y := 111;
  arr[1].X := 2; arr[1].Y := 222;
  arr[2].X := 3; arr[2].Y := 333;
  arr[3].X := 4; arr[3].Y := 444;
  arr[4].X := 5; arr[4].Y := 555;

  DeleteArrItem(@arr, 3);
  for i := 0 to Length(arr) - 1 do
    Memo1.Lines.Add(Format('%d, %d', [arr[i].X, arr[i].Y]));
end;