Delphi XE5 ComponentCount segmentation fault (Search parented tcomponent )

Question

This code collect all TFMXControls in a specified root component. Exam the parent and the component name leading. This code working fine in Win32 32.bit windows target, but not in Nexus (android platform) with page fault in LANC soubrutine first line. I have no idea.. :(

procedure  Twmenetlevel.collectXMLControl(root:TComponent;parent:Tcomponent;fieldleading:string;xmlnode:IXMLNode;controlsetting:boolean);
var n:IXMLNode;



procedure feldolgozas(c:tfmxobject);
var s:string;
    node:IXMLNode;
begin
    if lowercase(copy(c.Name,1,3))=fieldleading then
    begin
       s:=withoutnumbers(lowercase(c.Name));

       node:=xmlnode.ChildNodes.FindNode(s);
       if not assigned(node) then
       begin
         node:=xmlnode.AddChild(s);
       end;
       case controlsetting of
       false: begin //olvasás a kontrollokból az XML-be
          if c is tedit then
            node.Text:=(c as tedit).Text;
          if c is Tcalendaredit then
            node.Text:=(c as tCALENDARedit).Text;
          if c is TTimeEdit then
            node.Text:=(c as TTimeEdit).Text;
          if c is TNumberBox then
            node.Text:=(c as TNumberBox).Text;
       end;
       true:begin  // a kontrollok beállítása XML szerint
          if c is tedit then
            (c as tedit).Text:=node.Text;
          if c is Tcalendaredit then
            (c as tCALENDARedit).Text:=node.Text;
          if c is TTimeEdit then
            (c as TTimeEdit).Text:=node.Text;
          if c is TNumberBox then
            (c as TNumberBox).Text:=node.Text;

       end;
       end;
    end;
end;

function isparent(parent:tcomponent;prechild:tfmxobject):boolean;
begin
    result:=false;
    if assigned(prechild) then
    begin
        if prechild.parent=parent then
          result:=true
        else
        begin
           result:=isparent(parent,prechild.parent);
        end;
    end;
end;

procedure lanc(c:tcomponent);
var i,j:integer;
  cp:tcomponent;
begin
  j:=c.ComponentCount;
  for i := 0 to c.ComponentCount-1 do
  begin
    cp:=c.components[i];
    if (cp is tfmxobject) then
    begin
      if (isparent(parent,cp as tfmxobject)) then
      begin
         feldolgozas(c.components[i] as tfmxobject);
      end;
    end;
    lanc(c.components[i]);
  end;
end;

begin
   lanc(root);
end;

---

This not working too but it is very simple. (Win32 working fine) (Tform1 simple mobile form)

procedure TForm1.Button1Click(Sender: TObject);
    var
    i: Integer;
    s:string;
begin

for i := 0 to self.ComponentCount-1 do
begin
  s:=s+self.Components[i].Name;

end;
end;

Answer 1

The first line, the line that you claim faults, is:

j:=c.ComponentCount;

Since j is a local variable, we can conclude that c is the problem. So, clearly c is not a valid reference to an instance.

Now, c is the parameter of the function, and you passed root. From which I conclude that root, the parameter that you passed to Twmenetlevel.collectXMLControl, is invalid.

So your next step is to look at the call to Twmenetlevel.collectXMLControl and work out why the parameter that you passed is invalid.