The countdown is suspended when the IOS WeChat background is running.

When the IOS background is running, the countdown is suspended.

Link: https://pan.baidu.com/s/1i7cSkqL password: g80i

I recently played an H5 Q & A game for CCTV, but encountered a terminal problem during the countdown: After the mobile phone client presses the Home Key to generate the background, IOS11 will continue to run JS for five seconds, note that it is 5 seconds, that is, when the countdown is 9, the backend is received, and the JS will start to count down from 4 after one minute. I heard that IOS6 can run for 10 minutes, IOS7 has 3 minutes, And IOS11 only has 5 seconds .... however, TM is a BUG. You have to modify it. (PS: android can run normally in 10 s, and I have never tried to run it for several seconds. Maybe this is why the Android software is too choppy ). I chose to obtain the current timestamp to solve this problem. The specific code analysis is as follows:

　　

　　　　　　function Time_a() {                var time = 10;                $(".time").text(time);                var t = setInterval(function() {                    if(time == 0) {                        clearTimeout(t);                    } else {                        time--;                        $(".time").text(time)                    }                }, 1000)            }

When time --; is used for countdown, there will be a countdown fault on IOS11. Therefore, I chose to use the timestamp and use the background time limit to solve the background running time limit of IOS.

　　　　　　function Time_b(){                var time=10;                var beginTime=new Date().getTime();                $(".time-a").text(time);                var t= setInterval(function(){                    var newTime=new Date().getTime();                    var dTime=(newTime-beginTime)/1000;                    dTime=parseInt(dTime);                    time = 10-dTime > 0 ? 10-dTime : 0;                    $(".time-a").text(time);                },1000)                            }