1.js 定时器简单的轮询方式
1 <!DOCTYPE html> 2 <html> 3 <head> 4 <meta charset="UTF-8"> 5 <title></title> 6 </head> 7 <body> 8 <script> 9 10 // 轮询方法 11 function polling(timestamp,callback){ 12 var flag = 0,timestamp = timestamp || 5000,times=0,s, 13 func=function(timestamp,flag){ 14 if(timestamp == 1000){ 15 clearTimeout(s); 16 if(times == 10){ 17 clearInterval(s); 18 return; 19 }else{ 20 times++; 21 s = setInterval(function(){ 22 callback(); 23 func(timestamp,flag); 24 },1000) 25 } 26 }else{ 27 clearInterval(s); 28 callback(); 29 flag++; 30 if(flag % 2 !== 0){ 31 timestamp-=1000; 32 } 33 console.log(timestamp,flag,123) 34 s=setTimeout(function(){ 35 func(timestamp,flag) 36 },timestamp); 37 } 38 } 39 func(timestamp,flag); 40 } 41 // 这里定义轮询请求方法 42 function callback(){ 43 console.log(1111); 44 } 45 // 传入倒计时，每请求两次 间隔减少1s 46 polling(5000,callback); 47 </script> 48 </body> 49 </html>