原生js实现播放器

朴灿烈づ我的快乐病毒、 2024-04-20 09:43 86阅读 0赞

###### 播放器 ######

> 目的：可快退、快进、静音、调节声音、全屏、改变当前视频所在位置（以拖动形式和点击进度条的形式）

###### 遇到的问题： ######

① 谷歌浏览器上若用本地视频无法对`video`标签进行`currentTime`的设置  
② 在video的`oncanplay`事件触发前无法获取该视频的`duration`值  
③ 只要视频的时间改变都会触发`ontimeupdate`事件，若想要1s进度条移动 & 1s时间变化一次，可采用对`video.currentTime`向下求整的方式来实现。  
④ 当`video`的`playbackRate`改变时，其`currentTime`的改变速度变快，此时不是1s移动一次进度条 & 1s时间变化一次。而是与速度有关了，但时间仍是以整数变化的（无论是加速还是未加速，计算的`currentTime`都是整数值，时间和计算的`currentTime`有关，故仍以整数形式变化）。（不加快速度时，其默认播放速度为1,故可做到③）。  
⑤ 在快退时，不可将`video.playbackRate`设为-1。应该在定时器中减少`video.currentTime`的值来实现。

###### 1. **播放**和**暂停**切换 ######

> 在按播放时，视频开始播放，调用`video.play()`方法。在按暂停时，视频停止播放，调用`video.pause()`方法。在后续的快进和快退功能下，`video.playbackRate`会发生变化，当点击快进按钮时，若想要速度变为正常则需要点击暂停按钮，再点击播放按钮，此时播放速度变为正常速度。

play.onclick = function () { 
            clearInterval(timer);
            if(this.innerHTML=="播放"){ 
                this.innerHTML="暂停";
                video.play();
            }else{ 
                this.innerHTML = "播放";
                video.pause();
            }
            video.playbackRate = 1;
            range.value = initVolume * 100;
        };

###### 2. 视频时间变化 ######

> 在视频时间变化时，进度条、圆圈的位置以及当前视频时间也需要变化。由于视频时间只要变化就会调用`ontimeupdate`方法，若想1s变化一次，则可通过对`currentTime`向下求整的方式来实现。当视频播放到结尾时，`currentTime`变为0，暂停变为播放，即跳到视频的开始。用户点击播放可重新开始播放

video.ontimeupdate = function(){ 
            if(video.currentTime<=0){ 
                clearInterval(timer)
            }
            var currentTime = Math.floor(this.currentTime);//将当前时间向下求整做到变化几次当前时间后才移动进度条长度
            var width = (currentTime/this.duration)*parseInt(progressWidth);
            progressInner.style.width = width+"px";
            circle.style.left = (width-parseInt(circleWidth)/2)+"px";
            nowTime.innerHTML = setTime(currentTime);
            if(this.currentTime>=this.duration){ 
                play.innerHTML="播放";
                this.currentTime = 0;
            }
        };

###### 3. 快进 & 快退 ######

> 当点击快退时，创建计时器，视频停止播放。当快退至视频的开始时，清除计时器。

/* * 快进 * */
        go.onclick = function () { 
            video.playbackRate = 3;
        }
        /* * 快退 * */
        back.onclick = function () { 
            video.pause();
            play.innerHTML="播放";
            // video.playbackRate = -1;//不可为负数！！！
            timer = setInterval(function(){ 
                video.currentTime -= 2;
                console.log(video.currentTime)
            },500)
        }
        /* * 全屏 * */
        allScreen.onclick = function () { 
            /* * 考虑兼容性 * */
            if (video.requestFullscreen) { 
                video.requestFullscreen()
            }
            if (video.webkitRequestFullscreen) { 
                video.webkitRequestFullscreen()
            }
            if (video.mozRequestFullscreen) { 
                video.mozRequestFullscreen()
            }
            if (video.msRequestFullscreen) { 
                video.msRequestFullscreen()
            }
            if (video.oRequestFullscreen) { 
                video.oRequestFullscreen()
            }
        }

###### 4. 点击进度条，跳到点击的位置 ######

> 点击进度条，改变`video.currentTime`、进度条位置、圆圈位置和当前所在时间。

progress.onclick = function (e) { 
            var offset = e.clientX-progress.offsetLeft-videoOut.offsetLeft;
            var currentTime = (offset/parseInt(progressWidth))*video.duration;
            video.currentTime  = currentTime;
            var width = (currentTime/video.duration)*parseInt(progressWidth);
            progressInner.style.width = width+"px";
            circle.style.left = (width-parseInt(circleWidth)/2)+"px";
            nowTime.innerHTML = setTime(currentTime);
    
        }

###### 5. 当拖动圆圈时，改变视频播放位置 ######

> 当点击圆圈进行拖动时才能进行视频位置的移动。此时触发圆圈的`onousedown`事件。在移动的过程中，不仅可以在进度条上移动，也可以在整个视频的范围内移动，故需要设置视频的`onmousemove`事件，在其`onmouseup`事件触发的同时清除其`onmousemove`事件

circle.onmousedown = function() { 
            videoOut.onmousemove = function (e) { 
                var offset = e.clientX - this.offsetLeft - progress.offsetLeft;
                if (offset <= 300 && offset >= 0) { 
                    video.currentTime = (offset / parseInt(progressWidth)) * video.duration;
                    progressInner.style.width = offset + "px";
                    circle.style.left = (offset - parseInt(circleWidth) / 2) + "px";
                }
            }
        };
         videoOut.onmouseup = function(){ 
            //若外层写成video.onmouseup事件，则在底部progress处无法触发。。因为progress将其挡住
            this.onmousemove = null;//清空事件内容
        };

###### 完整代码 ######

<!DOCTYPE html>
    <html lang="en">
    <head>
        <meta charset="UTF-8">
        <title>Title</title>
    </head>
    <style> .video{ width: 600px; height: 400px; position: absolute; left: 0; right: 0; margin:auto; border:1px solid black; background: black; } .video>video{ width: 600px; height: 400px; } .video>.controls{ width: 100%; position: absolute; bottom: 0; height: 40px; background: white; } .controls>div:not(.time){ border-radius:50%; color: white; width: 30px; height: 30px; text-align: center; line-height: 30px; background: black; font-size: 12px; position: absolute; top:0; bottom:0; margin:auto; } .go{ left:32px; } .back{ left:64px } .progress{ border-radius:5px !important; left:96px; width: 300px !important; height: 6px !important; background: silver !important; } .progressInner{ background:gray; height:100%; width: 0; } .progress>.circle{ position:absolute; top:-3px; left:-6px; display: inline-block; border-radius:50%; background: black; width: 12px; height: 12px; } .mute{ right: 64px; } .volume{ right: 32px; } .allScreen{ right: 2px; } .time{ position: absolute; right: 98px; line-height: 40px; font-size: 12px; } #range{ display: none; transform:rotate(-90deg) !important; position: absolute; right: -18px; bottom: 90px; } </style>
    <body>
    <div class="video">
        <video src="http://smvideo.duowan.com/video_upload/14031.mp4"></video>
        <div class="controls">
            <div class="play">播放</div>
            <div class="go">快进</div>
            <div class="back">快退</div>
            <div class="progress">
                <div class="progressInner">
                </div>
                <span class="circle"></span>
            </div>
            <div class="time">
                <span class="nowTime">00:00:00</span>/
                <span class="allTime">00:00:45</span>
            </div>
            <div class="mute" data-num="0">静音</div>
            <div class="volume">音量</div>
            <div class="allScreen">全屏</div>
            <input type="range" value="0" min="0" max="100" id="range" orient="vertical">
        </div>
    </div>
    <script> var play = document.getElementsByClassName("play")[0]; var range = document.getElementById("range"); var go = document.getElementsByClassName("go")[0]; var back = document.getElementsByClassName("back")[0]; var video = document.getElementsByTagName("video")[0]; var nowTime = document.getElementsByClassName("nowTime")[0]; var videoOut = document.getElementsByClassName("video")[0]; var allTime = document.getElementsByClassName("allTime")[0]; var allScreen = document.getElementsByClassName("allScreen")[0]; var progress = document.getElementsByClassName("progress")[0]; var progressInner = document.getElementsByClassName("progressInner")[0]; var circle = document.getElementsByClassName("circle")[0]; var mute = document.getElementsByClassName("mute")[0]; var volume = document.getElementsByClassName("volume")[0]; var timer; var speed=1000; var oldSpeed; var initVolume; var nowVolume; var progressWidth = window.getComputedStyle(progress).width; var circleWidth = window.getComputedStyle(circle).width; circle.onmousedown = function() { videoOut.onmousemove = function (e) { var offset = e.clientX - this.offsetLeft - progress.offsetLeft; if (offset <= 300 && offset >= 0) { video.currentTime = (offset / parseInt(progressWidth)) * video.duration; progressInner.style.width = offset + "px"; circle.style.left = (offset - parseInt(circleWidth) / 2) + "px"; } } }; // progress.onmousemove = function (e) {//只在进度条控制 // var offset = e.clientX-this.offsetLeft-videoOut.offsetLeft; // if(offset<=300 && offset>=0){ // video.currentTime = (offset/parseInt(progressWidth))*video.duration; // progressInner.style.width = offset+"px"; // circle.style.left = (offset-parseInt(circleWidth)/2)+"px"; // } // } videoOut.onmouseup = function(){ //若外层写成video.onmouseup事件，则在底部progress处无法触发。。因为progress将其挡住 this.onmousemove = null;//清空事件内容 }; volume.onclick = function(){ if(range.style.display == "block"){ range.style.display = "none"; }else{ range.style.display = "block"; } }; range.onchange = function(){ var rate = this.value/this.max; video.volume = initVolume*rate; nowVolume = initVolume*rate; }; mute.onclick = function(){ if(this.getAttribute("data-num")=="0"){ video.muted = true; this.setAttribute("data-num","1"); range.value = 0; mute.style.background="red" }else{ video.muted = false; this.setAttribute("data-num","0"); range.value = nowVolume*range.max; mute.style.background="" } }; video.oncanplay = function () { allTime.innerHTML = setTime(this.duration); oldSpeed = this.playbackRate; initVolume = this.volume; nowVolume = initVolume; }; /* * 设置总时间和当前时间 * */ function setTime(time){ var str = ""; var time = time; var hour = Math.floor((time/(60*60))%(24)); str += hour<10 ? "0"+hour : hour; var minute = Math.floor((time/60)%60); str += minute<10 ? ":0"+minute : ":"+minute; var second = Math.floor(time%60); str += second<10 ? ":0"+second : ":"+second; return str; } /* * 切换播放和暂停 * */ play.onclick = function () { clearInterval(timer); if(this.innerHTML=="播放"){ this.innerHTML="暂停"; video.play(); }else{ this.innerHTML = "播放"; video.pause(); } video.playbackRate = 1; range.value = initVolume * 100; }; /* * 时间变化时调用 * */ video.ontimeupdate = function(){ if(video.currentTime<=0){ clearInterval(timer) } var currentTime = Math.floor(this.currentTime);//将当前时间向下求整做到变化几次当前时间后才移动进度条长度 var width = (currentTime/this.duration)*parseInt(progressWidth); progressInner.style.width = width+"px"; circle.style.left = (width-parseInt(circleWidth)/2)+"px"; nowTime.innerHTML = setTime(currentTime); if(this.currentTime>=this.duration){ play.innerHTML="播放"; this.currentTime = 0; } }; /* * 快进 * */ go.onclick = function () { video.playbackRate = 3; } /* * 快退 * */ back.onclick = function () { video.pause(); play.innerHTML="播放"; // video.playbackRate = -1;//不可为负数！！！ timer = setInterval(function(){ video.currentTime -= 2; console.log(video.currentTime) },500) } /* * 全屏 * */ allScreen.onclick = function () { /* * 考虑兼容性 * */ if (video.requestFullscreen) { video.requestFullscreen() } if (video.webkitRequestFullscreen) { video.webkitRequestFullscreen() } if (video.mozRequestFullscreen) { video.mozRequestFullscreen() } if (video.msRequestFullscreen) { video.msRequestFullscreen() } if (video.oRequestFullscreen) { video.oRequestFullscreen() } } /* * 点击进度条 * */ progress.onclick = function (e) { var offset = e.clientX-progress.offsetLeft-videoOut.offsetLeft; var currentTime = (offset/parseInt(progressWidth))*video.duration; video.currentTime = currentTime; var width = (currentTime/video.duration)*parseInt(progressWidth); progressInner.style.width = width+"px"; circle.style.left = (width-parseInt(circleWidth)/2)+"px"; nowTime.innerHTML = setTime(currentTime); } </script>
    </body>
    </html>