function Property() {
var xmlhttp;
if (window.XMLHttpRequest) {
xmlhttp = new XMLHttpRequest();
} else {
xmlhttp = new ActiveXObject("Microsoft .XMLHTTP");
}

xmlhttp.onreadystatechange = function() {
if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {
var datastr = xmlhttp .responseText;
alert(datastr);
var dataobj = JSON.parse(datastr)
let dataarr = [];
for (let i in dataobj) {
dataarr.push( dataobj[i]);
}

 
}
}

xmlhttp.open("POST", "https://api.123321yun.com/api /device/queryProjectDeviceParamStatus?projId=66", true);

/* xmlhttp.open("POST", "https://api.123321yun.com/api/user/login?username=test123&password= 123456", true);*/ xmlhttp.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
xmlhttp.send();
}

Xiaobai wants to solve the problem that the login status cannot be saved