AJAX之超時與網絡異常處理

<script> //獲取button const btn = document.getElementsByClassName("button")[0]; console.log(btn) //綁定事件 btn.addEventListener("click",function(){ //創建對象 const xhr = new XMLHttpRequest(); //初始化對象 xhr.open("POST","http://localhost:8000/ie?t="+Date.now()); xhr.setRequestHeader("Content-Type","application/x-www-form-urlencoded"); //設置請求頭 xhr.setRequestHeader("name1","ddd"); //發送 xhr.send("a=3&b=4"); //設置超時 xhr.timeout=2000; //超時回調 xhr.ontimeout=function(){ alert("你的網絡超時了") } //網絡異常 xhr.onerror=function(){ alert("你斷網了") } //事件綁定 xhr.onreadystatechange=function(){ //判斷響應 if( xhr.readyState ===4 ){ if(xhr.status >=200 && xhr.status <300){ div.innerHTML=xhr.response; } } } }) </script>