function createCsvFile(){

  var fileName = "ooooo.csv";//匯出的檔名

  var data = getRandomData();

  var blob = new Blob([data], {

    type : "application/octet-stream"

  });

  var href = URL.createObjectURL(blob);

  var link = document.createElement("a");

  document.body.appendChild(link);

  link.href = href;

  link.download = fileName;

  link.click();

}

//隨機產生資料

function getRandomData() {

  var header = "第一欄,第二欄,第三欄,第四欄,第五欄\n";

  var data = "";

  for (var i = 0; i < 50; i++) {

      for (var j = 0; j < 5; j++) {

        if(j>0){

            data = data + ",";

        }

        data = data + "Item" + i + "_" + j;

      }

      data = data + "\n";

  }

  return header+data;

}