Nachdem Sie ihm gefolgt sind, können Sie seine dynamischen Informationen zeitnah verfolgen
Kurse in der entsprechenden Rubrik：对象的创建和兼容处理
<!doctype html> <html lang="en"> <head> <meta charset="UTF-8"> <title>ajax</title> </head> <body> <script> window.onload = function(){ var btn = document.getElementById("btn"); btn.onclick = function(){ // var xhr = null; // if(window.XMLHttpRequest){ // var xhr = new XMLHttpRequest(); // }else{ // var xhr = new ActiveXObject('Microsoft.XMLHTTP'); // } try{ var xhr = new XMLHttpRequest(); }catch(e){ var xhr = new ActiveXObject('Microsoft.XMLHTTP'); } xhr.open('get','ajax.txt',true); xhr.send(); xhr.onreadystatechange = function(){ if(xhr.readyState == 0){ alert("请求未初始化"); }else if(xhr.readyState == 1){ alert("服务器连接已建立"); }else if(xhr.readyState == 2){ alert("请求已接收"); }else if(xhr.readyState == 3){ alert("请求处理中"); }else{ alert(xhr.responseText); } } } } </script> <input type="button" value="获取ajax" id="btn"> </body> </html>
2018-05-250个赞
