Box=document.getElementById('
Box');
var oDrag=document.getElementById('drag');
var content=document.getElementById('content');
var viewHeight=document.documentElement.clientHeight;
var conHeight=content.clientHeight
o
Box.style.height=viewHeight+'px';
oDrag.style.height=viewHeight/conHeight*viewHeight+'px';
window.onresize = function(){
viewHeight=document.documentElement.clientHeight;
o
Box.style.height=viewHeight+'px';
oDrag.style.height=viewHeight/conHeight*viewHeight+'px';
oDrag.style.top=-content.offsetTop/(content.clientHeight-viewHeight)*(o
Box.clientHeight-oDrag.clientHeight)+'px';
}
oDrag.onmousedown=function (ev){
//阻止默认事件
var e=ev||window.event;
if (e.preventDefault) {
e.preventDefault();
} else{
e.returnValue=false;
};
//e.clientY鼠标当前坐标
var downY=e.clientY-oDrag.offsetTop;
document.onmousemove=function (ev){
var e=ev||window.event;
var top=e.clientY-downY;
if (top<=0) {
top=0;
};
if (top>=o
Box.clientHeight-oDrag.clientHeight) {
top=o
Box.clientHeight-oDrag.clientHeight;
};
var scale=top/(o
Box.clientHeight-oDrag.clientHeight);
var contentY=scale*(content.clientHeight-viewHeight);
oDrag.style.top=top+'px';
content.style.top=-contentY+'px';
}
document.onmouseup=function (){
document.onmousemove=null;
}
}
var str=window.navigator.userAgent.toLowerCase();
//火狐浏览器
if (str.indexOf('firefox')!=-1){
document.addEventListener('DOMMouseScroll',function (e){
e.preventDefault();//阻止窗口默认的滚动事件
if (e.detail<0) {
var scrollHei=content.offsetTop+25;
if (scrollHei>=0) {
scrollHei=0;
};
if (scrollHei<=-(content.clientHeight-viewHeight)) {
scrollHei=-(content.clientHeight-viewHeight);
};
var scale=scrollHei/(content.clientHeight-viewHeight);
var top=scale*(oBox.clientHeight-oDrag.clientHeight);
content.style.top=scrollHei+'px';
oDrag.style.top=-top+'px';
}
if (e.detail>0) {
var scrollHei=content.offsetTop-25;
if (scrollHei>=0) {
scrollHei=0;
};
if (scrollHei<=-(content.clientHeight-viewHeight)) {
scrollHei=-(content.clientHeight-viewHeight);
};
var scale=scrollHei/(content.clientHeight-viewHeight);
var top=scale*(oBox.clientHeight-oDrag.clientHeight);
content.style.top=scrollHei+'px';
oDrag.style.top=-top+'px';
};
},false);
}
else{//非火狐浏览器
document.onmousewheel=function (ev){
var e=ev||window.event;
if (e.preventDefault) {
e.preventDefault();
} else{
e.returnValue=false;
};
if (e.wheelDelta>0) {
var scrollHei=content.offsetTop+25;
if (scrollHei>=0) {
scrollHei=0;
};
if (scrollHei<=-(content.clientHeight-viewHeight)) {
scrollHei=-(content.clientHeight-viewHeight);
};
var scale=scrollHei/(content.clientHeight-viewHeight);
var top=scale*(o
Box.clientHeight-oDrag.clientHeight);
content.style.top=scrollHei+'px';
oDrag.style.top=-top+'px';
};
if (e.wheelDelta<0) {
var scrollHei=content.offsetTop-25;
if (scrollHei>=0) {
scrollHei=0;
};
if (scrollHei<=-(content.clientHeight-viewHeight)) {
scrollHei=-(content.clientHeight-viewHeight);
};
var scale=scrollHei/(content.clientHeight-viewHeight);
var top=scale*(o
Box.clientHeight-oDrag.clientHeight);
content.style.top=scrollHei+'px';
oDrag.style.top=-top+'px';
};
}
}
}