# 实用-ajax
const getJSON = function(url) {
return new Promise((resolve, reject) => {
const xhr = XMLHttpRequest ? new XMLHttpRequest() : new ActiveXObject('Mscrosoft.XMLHttp');
xhr.open('GET', url, false);
xhr.setRequestHeader('Accept', 'application/json');
xhr.onreadystatechange = function() {
if (xhr.readyState !== 4) return;
if (xhr.status === 200 || xhr.status === 304) {
resolve(xhr.responseText);
} else {
reject(new Error(xhr.responseText));
}
}
xhr.send();
})
}
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17