CODEWITHSUNDEEP
delphisortingdelphi-xe2implementationfiremonkey
Whiler
Whiler

Reputation: 8086

How to implement a FireMonkey TStringGrid Sort function: TFMXObjectSortCompare?

type
  TMyForm= class(TForm)
    sg       : TStringGrid;
    imgSortIt: TImage;
    ...
    procedure imgSortItClick(Sender: TObject);
  private
    { Private declarations }
//    sortIt: TFMXObjectSortCompare;
    function sortIt(item1, item2: TFmxObject): Integer;
  public
    { Public declarations }
  end;

var
  frm: TMyForm;

implementation

{$R *.fmx}

procedure TMyForm.imgSortItClick(Sender: TObject);
begin
  sg.Sort(???);
...

Hi,

I know how to switch rows to manually sort a grid...

But as a TSTringGrid has a procedure Sort, I try to use it with my own comparison function with this procedure...

How should I structure the type/function to make it work? Actually, I get:

Thanks for your help.

Upvotes: 1

Views: 2186

Answers (1)

David Heffernan
David Heffernan

Reputation: 612993

You are looking at the XE3 documentation, according to which TFmxObjectSortCompare is declared as:

reference to function(Right, Left: TFmxObject): Integer;

In XE2, unfortunately, TFmxObjectSortCompare is declared like this:

function(item1, item2: TFmxObject): Integer;

So you will need to supply a regular procedure. That is, sortIt is not allowed to be a method of a class and must be just a plain old function:

function sortIt(item1, item2: TFmxObject): Integer;
begin
  Result := ...
end;

I suspect that this was a design error in the XE2 FMX code. The sort compare function is much more flexible as reference to, which presumably is why it was changed.

Upvotes: 1

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