原生ajax

Create a ajax

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
if (window.ActiveXObject) {
xhr = new ActiveXObject("Microsoft.XMLHTTP");
} else if (window.XMLHttpRequest) {
xhr = new XMLHttpRequest();
}
xhr.open("post",url, true);
xhr.onload = function (evt){
var data = JSON.parse(evt.target.responseText);
// TODO AFTER
console.log(data)
}
xhr.onerror = () {
console.log('ERROR')
};
xhr.upload.onloadstart = (){
console.log('start');
};
xhr.send(form);

form data

有了它 ,可以轻轻松松把数据传给后端。
MDN formData

1
2
let formData = new FormData(); 
formData.append('username', 'Chris');