Js——滾輪事件 自定義滾動條的實現
阿新 • • 發佈：2019-01-08
描述：
自定義滾動條的實現
效果：
實現：
<!DOCTYPE html> <html lang=""> <head> <meta charset="utf-8"> <title></title> <style> * {margin: 0;padding: 0;} html,body { width: 100%;height: 100%;} #box { width: 100%; height: 100%; overflow: hidden;} /*一個個划過去的頁面塊*/ .ball { width: 100%; height: 500px; font-size:100px; font-weight:bold; color: skyblue; text-align: center; line-height:500px; } /*//滾動欄*/ #scroll { width: 20px; height: 96%; position: fixed; top: 2%; right: 5px; border-radius: 10px; background-color: rgba(235, 233, 233, 0.5); z-index: 9998; opacity: 0; } /*//滾動欄上的小長條*/ #scrollBar { position: absolute; z-index: 1;/*//定在上面*/ width: 20px; height: 40px; border-radius: 10px; left: 0; top: 0; background-color: red;opacity: 0.6; } </style> </head> <body style="overflow:hidden;"> <div id="box"> <div id="content"> <!--//營造div色塊交替的感覺--> <p class="ball" style="background-color:#656565;">1</p> <p class="ball" style="background-color:#ffffff;">2</p> <p class="ball" style="background-color:#656565;">3</p> <p class="ball" style="background-color:#ffffff;">4</p> <p class="ball" style="background-color:#656565;">5</p> <p class="ball" style="background-color:#ffffff;">6</p> </div> </div> <div id="scroll"> <div id="scrollBar"></div> </div> </body> </html> <script type="text/javascript"> var content = document.getElementById("content"); var box = document.getElementById("box"); var scroll = document.getElementById("scroll"); var scrollBar = document.getElementById("scrollBar"); var Step = { value : 0, size : 20, maxVal : Math.ceil((content.offsetHeight-document.body.offsetHeight)/20), getCurrentVal:function(){ return this.value; }, next:function(){ if(this.value==this.maxVal) return; this.value++; }, pre:function(){ if(this.value==0) return; this.value--; }, getDistance:function(){ return this.getCurrentVal()*this.size; }, update:function(){ this.maxVal = Math.ceil((content.offsetHeight-document.body.offsetHeight)/this.size); } } window.addEventListener("resize",function(){ Step.update(); }); box.addEventListener("DOMMouseScroll",scrollfunc); box.addEventListener("mousewheel", scrollfunc); function scrollfunc(e){ if(e.type=="mousewheel"){ //非FF e.wheelDelta<0?Step.next():Step.pre(); } else { //FF e.detail>0?Step.next():Step.pre(); } document.title = Step.getCurrentVal(); box.scrollTop = Math.min(Step.getDistance(),content.offsetHeight-document.body.offsetHeight); //計算滾動比例 var percent = box.scrollTop/(content.offsetHeight-document.body.offsetHeight); //顯示滾動條 scroll.style.opacity = 100; //計算滾動條的位置 scrollBar.style.top = (scroll.offsetHeight-scrollBar.offsetHeight)*percent + "px"; } </script>