How to save this: 1

[MrDoch]

Hi All,

Can someone tell me how to save the YValues from a chart?
I have tried with something like:

Chart1.SeriesList.Series[0].YValues.SaveToFile(SaveDialog1.FileName);

But then it writes: undeclared identifier 'SaveToFile'.
What is the problem?

 

[roo0047]

Chart1.SeriesList.Series[0].YValues.SaveToFile(SaveDialog1.FileName);

Look up properties (in help) for whatever component type 'YValues' is.
Does it have a method 'SaveToFile'?

Roo
Delphi Rules!

 

[MrDoch]

I have found the following, but it does not help me going on:

Proberty YValue[Index:Longint]ouble

I can save a StringList without problems by writing:
StringList.SaveToFile(SaveDialog1.FileName);

I am pretty sure I cannot use SaveToFile in this case, but what else?

Regards

 

[Stretchwickster]

Here is a quick example which will work:

var
  i: Integer;
  values: TStringList;
begin
  values := TStringList.Create;
  try
    for i := 0 to Chart1.Series[0].YValues.Count - 1 do
      values.Add(FloatToStr(Chart1.SeriesList.Series[0].YValues.Value[i]));
    values.SaveToFile('C:\ChartYValues.txt') 
  finally
    values.Free;
  end;
end;

It loops through all the items in the YValues list and adds them to a TStringList, before saving to file.

Hope this helps!

Clive
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
"To err is human, but to really foul things up you need a computer."
Paul Ehrlich
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
To get the best answers from this forum see: faq102-5096

 

[MrDoch]

Hi,

That helped a lot!

Now there is only one problem:
When I have saved the StringList, and try to open it again (LoadFromFile), then I get an "Access Violation".
I can solve this by chanching Values.free to Values.Clear,
but I do really want to free the memory after saving the List.. Thanks in advance.

 

[Stretchwickster]

You get an access violation because you are trying to access memory that has already been freed. If you want to load it in a different place in the program then use something like this:

var
  values: TStringList;
begin
  values := TStringList.Create;
  try
    values.LoadFromFile('C:\ChartYValues.txt') 
    { do some processing on the stringlist }
  finally
    values.Free;
  end;
end;

or alternatively declare the TStringList as a variable of the form/class/unit and create it in the appropriate constructor and destroy it in the appropriate destructor. That way it is persistent for longer than a single method.

Clive
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
"To err is human, but to really foul things up you need a computer."
Paul Ehrlich
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
To get the best answers from this forum see: faq102-5096

 

[MrDoch]

Perfect, thank you very much!

Do I have to close this question, or how does it work here?

 

[Stretchwickster]

There is no official closure for threads - simply accepting the answer with a comment such as "thank you very much!" or "that worked" is sufficient in showing your question was answered satisfactorily.

Although I'm not trying to hint at awarding me a star, there is a star award scheme for helpful posts. You'll notice there is a "Thank [handle] for this valuable post!" link under each post. By clicking this you can award a star for each helpful post. You can only award one to each respondent.

Clive
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
"To err is human, but to really foul things up you need a computer."
Paul Ehrlich
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
To get the best answers from this forum see: faq102-5096