动态数组的使用

动态数组在声明时，只需要声明成员的类型，并不需要指定程序的序号，可在运行期间动态改变成员数量

http://www.cnblogs.com/del/archive/2009/11/11/1600876.html

//动态数组地址测试
var
  i: Integer;
  arr: TBytes;
  p: PByte;
begin
  SetLength(arr, 5);
  for i := 0 to 4 do arr[i] := i + 65;
  ShowMessage(StringOf(arr)); {ABCDE}

  p := PByte(arr);
  ShowMessage(Chr(p^)); {A}

  p := PByte(@arr[2]);
  ShowMessage(Chr(p^)); {C}

  p^ := Ord('-');
  ShowMessage(StringOf(arr)); {AB-DE}
end;

//合并两个动态数组:
var
  arr1,arr2: TBytes;
  len: Integer;
begin
  SetLength(arr1, 3);
  SetLength(arr2, 3);

  arr1[0] := 65; arr1[1] := 66; arr1[2] := 67;
  arr2[0] := 68; arr2[1] := 69; arr2[2] := 70;

  len := Length(arr1);
  SetLength(arr1, len + Length(arr2));

  CopyMemory(@arr1[len], arr2, Length(arr2));
  ShowMessage(StringOf(arr1)); {ABCDEF}
end;