customize X-Axis time axis

[bdw]

Hello,

We have a x-axis set to TDateTime which we set the BottomAxis->DateTimeFormat to "hh:nn" when showing less that 24 hours worth of data.

Is it possible to display at the day change over (i.e. 00:00 label) a different DateTimeFormat rather than hh:nn let say "ddd" or day + month ?

[Yeray]

Hello,

You could use the OnGetAxisLabel. However, once you are in this event, you don't know the value for the current label. You already have the formatted label.
So you could set a DateTimeFormat that allows you to identify both the "ddd" (or the "dd/mm") and the "hh:nn". Here you have an example:

Code: Select all

uses Series, DateUtils, StrUtils;

procedure TForm1.FormCreate(Sender: TObject);
var i: Integer;
begin
  Chart1.View3D:=false;

  with Chart1.AddSeries(TPointSeries) as TPointSeries do
  begin
    XValues.DateTime:=true;
    for i:=0 to 60 do
      AddXY(IncHour(Today, i), i);
  end;

  Chart1.Axes.Bottom.DateTimeFormat:='dd/mm hh:nn';
end;

procedure TForm1.Chart1GetAxisLabel(Sender: TChartAxis;
  Series: TChartSeries; ValueIndex: Integer; var LabelText: String);
var p: Integer;
begin
  if Sender = Chart1.Axes.Bottom then
  begin
    p:=AnsiPos(' ', LabelText);
    if AnsiEndsStr('00:00', LabelText) then
      LabelText:=Trim(AnsiLeftStr(LabelText, p))
    else
      LabelText:=Trim(AnsiRightStr(LabelText, p));
  end;
end;