Deprecation Synchronous XMLHttpRequest

问题

I see this error: "[Deprecation] Synchronous XMLHttpRequest on the main thread is deprecated because of its detrimental effects to the end user's experience. For more help, check https://xhr.spec.whatwg.org/.", on this code:

var request;
if(window.XMLHttpRequest){
    request = new XMLHttpRequest();
}else{
    request = new ActiveXObject("Microsoft.XMLHTTP");
}
request.open('GET', 'http://www.mywebsite.com', false);
request.send();

What should I replace the instructions with because they are deprecated?

回答1:

you just need to change

request.open('GET', 'http://www.mywebsite.com', false);

to

request.open('GET', 'http://www.mywebsite.com', true);

回答2:

request.open('GET', 'http://www.mywebsite.com', false)

It means you are creating a synchronous call to the Web service. So not expecting any call back theoratically.

So to continue with above approach make sure the body is also null.

request.send(null);

if (request.status === 200) {
  console.log(request.responseText);
}

The null parameter indicates that no body content is needed for the GET request. Hence the thread won't be blocked.

来源：https://stackoverflow.com/questions/48257085/deprecation-synchronous-xmlhttprequest