通過document.hidden屬性判斷當前頁面是否是激活狀態

網頁當前狀態判斷，若不處於當前窗口則不發請求

var interval_output = null;
function sendRequst() {
     interval_output = setInterval(function () {
        SetClock();
    }, 60000);
}
sendRequst();

var hiddenProperty = 'hidden' in document ? 'hidden' :
'webkitHidden' in document ? 'webkitHidden' :
'mozHidden' in document ? 'mozHidden' :null;

var visibilityChangeEvent = hiddenProperty.replace(/hidden/i, 'visibilitychange');
var onVisibilityChange = function () {
if (!document[hiddenProperty]) {
     // console.log('頁面激活')
        sendRequst();
   } else {
      //console.log('頁面非激活');
       clearInterval(interval_output);
  }
}
document.addEventListener(visibilityChangeEvent, onVisibilityChange);