javascript - 如何捕获涉及 XmlHttpRequest 的错误？

Question

当我通过 XMLHttpRequest 向服务器发送数据时，我想借助 TRY {} CATCH(){} 捕获所有错误。

如何接收所有的错误，例如net::ERR_INTERNET_DISCONNECTED等？

Answer 1

try catch 对我不起作用。我个人最终测试了 response == ""和 status == 0。

        var req = new XMLHttpRequest();
        req.open("post", VALIDATE_URL, true);
        req.onreadystatechange = function receiveResponse() {

            if (this.readyState == 4) {
                if (this.status == 200) {
                    console.log("We got a response : " + this.response);
                } else if (!isValid(this.response) && this.status == 0) {
                    console.log("The computer appears to be offline.");
                }
            }
        };
        req.send(payload);
        req = null;