刚入门前端请问js的跨域请求应该怎么解决?chatGpt都问了个遍写给出的三种写法代码如下
var url = "https://c.y.qq.com/tips/fcgi-bin/fcg_music_red_dota.fcg?_=1685457629182&cv=4747474&ct=24&format=json&inCharset=utf-8&outCharset=utf-8¬ice=0&platform=yqq.json&needNewCode=1&uin=0&g_tk_new_20200303=5381&g_tk=5381&cid=205360410&qq=0&reqtype=1&from=2"
// 创建 XMLHttpRequest 对象
const xhr = new XMLHttpRequest();
// 初始化 XMLHttpRequest 对象,设置请求方式、请求地址和是否异步
xhr.open('GET', url, true);
// 设置请求头部信息,用于携带 token 或其他信息
xhr.setRequestHeader('Content-type', 'application/json');
// 设置跨域请求的 withCredentials 为 true
xhr.withCredentials = true;
// 设置 XMLHttpRequest 对象的 onreadystatechange 方法
xhr.onreadystatechange = function () {
// readyState 等于 4 表示请求已完成,status 等于 200 表示请求成功
if (xhr.readyState === XMLHttpRequest.DONE && xhr.status === 200) {
// 成功获取到数据,进行处理
console.log(xhr.responseText);
}
};
// 发送 AJAX 请求
xhr.send();
// 定义一个名为 jsonp 的函数,用于接收 callback 返回的数据
function jsonp(url2) {
// 创建一个 script 标签
const script = document.createElement('script');
// 将 src 属性设置为 url + '?callback=' + callback
script.src = url2
// 将 script 标签添加到页面的头部
document.head.appendChild(script);
// 在 script 标签加载完毕后,将其从页面中移除
script.onload = function () {
document.head.removeChild(script);
};
};
// 调用 jsonp 函数,请求跨域的数据
jsonp(url);
// showData 将会在请求到数据后被回调
function showData(data) {
console.log(data);
}
fetch(url)
.then(response => {
if (!response.ok) {
throw new Error('Network response was not ok');
}
return response.json();
})
.then(data => {
console.log(data);
})
.catch(error => {
console.error('There was a problem with the fetch operation: ', error);
});
这三种写法仍然是报
Access to XMLHttpRequest at 'https://c.y.qq.com/tips/fcgi-bin/fcg_music_red_dota.fcg?_=1685457629182&cv=4747474&ct=24&format=json&inCharset=utf-8&outCharset=utf-8¬ice=0&platform=yqq.json&needNewCode=1&uin=0&g_tk_new_20200303=5381&g_tk=5381&cid=205360410&qq=0&reqtype=1&from=2%27 from origin 'null' has been blocked by CORS policy: Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource.