利用原生js實現自定義滾動條(可點選到達,拖動到達)
阿新 • • 發佈:2018-11-24
1.HTML檔案
div1是滾動條,div2是滾動小球,div3是文字區域容器,div4是文字區域。
<div id="div">
<div id="div1">
<div id="div2"> </div>
</div>
<div id="div3">
<div id="div4">
<p>CSS3 教程</p>
<p>CSS3 教程</p>
<p>CSS3 簡介</p>
<p> CSS3 邊框</p>
<p>CSS3 圓角</p>
<p>CSS3 背景</p>
<p>CSS3 漸變</p>
<p>CSS3 文字效果</p>
<p>CSS3 字型</p>
<p>CSS3 2D 轉換</p>
<p>CSS3 3D 轉換</p>
<p>CSS3 過渡</p>
<p>CSS3 動畫</p>
<p>CSS3 多列</ p>
<p>CSS3 使用者介面</p>
<p>CSS3 圖片</p>
<p>CSS3 按鈕</p>
<p>CSS3 分頁</p>
<p>CSS3 框大小</p>
<p>CSS3 彈性盒子</p>
<p>CSS3 多媒體查詢</p>
<p>CSS3 多媒體查詢例項</p>
</div>
</div>
</div>
2.css樣式檔案
通過容器溢位隱藏,文字區域的絕對定位,然後再交給js處理。
*{padding: 0; margin: 0;}
#div{top:200px;left:25%;width: 50%;height: 300px; position: absolute;
}
#div1{width: 20px; height: 300px; position: relative;
background: #CCCCCC; border-radius: 28px; float: right; cursor: pointer;}
#div1 #div2{left: -4px;width: 28px;height: 28px;border-radius: 50%; background: red;
position: absolute;}
#div3{width: 90%; height: 300px; border: 2px solid #CCCCCC;
position: relative; float: left; overflow: hidden;}
#div3 #div4{top:0;left:0;width: 100%; position: absolute; font-family: "微軟雅黑";
font-size: 19px; letter-spacing: 1px; padding: 3px 6px;}
3.js指令碼程式碼
window.onload =function(){
var allDiv =document.getElementById('div');
var oDiv =document.getElementById('div2');
var aDiv =document.getElementById('div1');
var textDiv1 =document.getElementById('div3');
var textDiv2 =document.getElementById('div4');
// 進度條拖動,內容跟著運動事件
oDiv.onmousedown =function(ev){
var oEvent =ev||event;
var disY =oEvent.clientY -oDiv.offsetTop;
if(oDiv.setCapture){
oDiv.onmousemove =mouseMove;
oDiv.onmouseup =mouseUp;
oDiv.setCapture();
}else{
document.onmousemove =mouseMove;
document.onmouseup =mouseUp;
}
function mouseMove(ev){
var oEvent =ev||event;
var t =oEvent.clientY -disY;
var bottomLine = aDiv.offsetHeight-oDiv.offsetHeight;
if(t <0){
t =0;
}else if(t >bottomLine){
t =bottomLine;
}
var percent =t/272;
oDiv.style.top =t+'px';
textDiv2.style.top =-(textDiv2.offsetHeight-textDiv1.offsetHeight)*percent+'px';
};
function mouseUp(){
this.onmousemove =null;
this.onmouseup =null;
if(oDiv.releaseCapture){
oDiv.releaseCapture();
}
};
return false;
};
// 點選進度條,開啟定時器,小球做勻速運動到達後,清楚定時器
aDiv.onmousedown=function(ev){
var oEvent =ev||event;
var divY =oEvent.clientY-allDiv.offsetTop;
var timer =null;var speed=10;
clearInterval(timer)
timer = setInterval(function(){
var percent=oDiv.offsetTop/272;
if(oDiv.offsetTop<divY-28){
oDiv.style.top =oDiv.offsetTop + speed +'px';
textDiv2.style.top =-(textDiv2.offsetHeight-textDiv1.offsetHeight)*percent +'px';
}else if(oDiv.offsetTop>divY){
oDiv.style.top =oDiv.offsetTop - speed +'px';
textDiv2.style.top =-(textDiv2.offsetHeight-textDiv1.offsetHeight)*percent +'px';
}else if(oDiv.offsetTop>260){
oDiv.offsetTop = 272+'px';
clearInterval(timer);
}else if(oDiv.offsetTop<10){
oDiv.offsetTop = 0+'px';
clearInterval(timer);
}else{
clearInterval(timer);
}
},10);
}
}