Acionar Guilhotina

type
  TMainForm = class(TForm)
   ....
  private
    { Private declarations }
  public
    { Public declarations }
    function FileExists(s: string): boolean;
    function CallMethod(Instance: TObject; ClassType: TClass;
      const MethodName: string; var Params: Variant): Variant;
  end;

function TMainForm.FileExists(s: string): boolean;
begin
  result := SysUtils.FileExists(s);
end;

function TMainForm.CallMethod(Instance: TObject; ClassType: TClass;
  const MethodName: string; var Params: Variant): Variant;
begin
  // dispatch the method call 
  if MethodName = 'FILEEXISTS' then
    result := FileExists(Params[0]);
  ...

procedure TMainForm.FormCreate(Sender: TObject);
const
  g='User Functions/Procedures';
begin
  // frGlobalUnit contains standard types and functions
  frxReport.Script.Parent := fsGlobalUnit;
  frxReport.Script.AddMethod('function FileExists(fName: String): Boolean',
    MainForm.CallMethod,g,'Checks if a given FileName <fName> Exists');
   ....

in the code of the report:

function CheckFileName(s: string): string;
begin
  s := VarToStr(s);
  s := Trim(s);
  if s > '' then begin
    result := s;
    if not FileExists(s) then begin
      //
      // filename given, but not found
      // so write to error log
      //if (dbg=TRUE) then begin
     //  s := 'file not found: ' + s + #13#10;
     //   fs.Write(s, Length(s));
     // end;
      // zero the string
      result := '';
    end;
  end;
end;

procedure BeforePrint(fName: string; img: TfrxPictureView);
begin
  fName := CheckFileName(fName);
  if (fName > '') then
    img.picture.LoadFromFile(fName)
  else
    img.Picture := nil;
// or add a gfx not found img?
//  img.picture.LoadFromFile('error.jpg')
end;

procedure imgBackOnBeforePrint(Sender: TfrxComponent);
begin
  BeforePrint(<DisksDB."Back">, imgBack);
end;

procedure imgBackOnAfterPrint(Sender: TfrxComponent);
begin
  // nil the component or it will carry over to next record
  imgBack.Picture := nil;
end;