Question

所以我对javascript的知识非常有限，所以我提前为我的愚蠢道歉。

我正在努力使这些警报在网站最初打开后16秒播放。在后台，有一个视频播放，似乎视频对网站有影响，但实际上，它只是以特定的方式播放。我如何才能获得这三个警报从网站开放16秒后播放？你把settimeout放在哪里，或者你在代码中的哪个位置放置了函数的持续时间？

再次，我真的不知道javascript，所以请在哪里把setTimeout放在这段代码中？

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
<title>eve_</title>
<link rel="icon" rel="preload" href="images/evecircle.png" />
<style>

#video {
    margin-left:-10px;
    margin-top:-10px;
}

</style>
</head>
<script>

function myText() {
    var txt;
    var person = prompt("What's your name?", "");
    if (person == null || person == "") {
        txt = "User cancelled the prompt.";
    } else {
        txt = "Hello " + person + "! How are you today?";
    }
    document.getElementById("demo").innerHTML = txt;
}



function playAlert(msg, wav) {

    return new Promise(function(resolve) {
        var audio = new Audio(wav);
        audio.addEventListener('canplay', function(e) {
            audio.play();
            alert(msg);
            resolve();

        });
    });
}
playAlert("1", 'Images/thankyou.wav')
.then(function() {
    return playAlert("2", 'Images/sorry.wav');
})
.then(function() {
    return myText("3", 'Images/mynameiseve.wav');
});



</script>
<body>
<video autoplay="autoplay" preload="metadata" id="video" src="images/secondnew.mp4" width="1300px" height="auto" style="position:absolute; z-index:-1;" >
        Video not supported.
         </video>
</body>
</html>

Answer 1

您可以在声明的函数之前使用它：playAlert()

所以：

let timeInMs = 16000; // set the time in Milisecond here setTimeout(playAlert("1", 'Images/thankyou.wav'), timeInMs);

Answer 2

使用＆＃34; ready＆＃34;文件的事件。 ---这个事件在DOM加载后触发。

function playAllAlerts(){
  // do your things
}
document.addEventListener('DOMContentLoaded', function() {
  setTimeout(playAllAlerts,16000)); // note playAllAlerts, not playAllAlerts()
});

＆＃13;

    function playAllAlerts(){
      console.log('Thing 1');
      console.log('Thing 2');
    }
    document.addEventListener('DOMContentLoaded', function() {
      setTimeout(playAllAlerts,1000); // note playAllAlerts, not playAllAlerts()
    });

＆＃13;

<div></div>

＆＃13;

不知道在哪里放置settimeout

2 个答案: