function SubStrConut(mStr: string; mSub: string): Integer;
{ 返回子字符串出现的次数 }
begin
  Result :=
    (Length(mStr) - Length(StringReplace(mStr, mSub, '', [rfReplaceAll]))) div
    Length(mSub);
end; { SubStrConut }

procedure TForm1.Button1Click(Sender: TObject);
begin
  Caption := IntToStr(SubStrConut(Edit1.Text, Edit2.Text));
end;