(function (window) {

//添加事件的方法通用所有
function addevent(evetname, fn, obj) {
if (document.attachEvent) { //ie9一下
obj.attachEvent("on" + evetname, function () {
fn.call(obj);
});
}
else {
obj.addEventListener(evetname, fn, false);

}
}

//通过类名获得元素
function getbyglass(classname, oparent) {

var ss = [];
if (!oparent) {
oparent = document;
}

var elements = oparent.getElementsByTagName("*");

if (document.getElementsByClassName) {

ss = oparent.getElementsByClassName(classname);

} else {
for (var i = 0; i < elements.length; i++) {
var obj = elements[i];
if (obj.className == classname) {

ss.push(obj);
}
}
}
return ss;
}

//得到元素的当前某个样式
function getStyle(element, stylename) {

if (element.currentStyle) {

return element.currentStyle[stylename];//ie下独有 不兼容部分

} else {

return window.getComputedStyle(element, false)[stylename];
}

}

//得到当前元素的绝对据上边距离 据下边距离
function getOffset(element) {

var x = element.offsetLeft;
var y = element.offsetTop;
if (element.parentElement != null) {
x += element.parentElement.offsetLeft;
y += element.parentElement.offsetTop;
element = element.parentElement;
}
return { x: x, y: y };
}

//构造函数
function DpQuery(context) {

return new DpQuery.prototype.inint(context);

}

DpQuery.prototype.inint = function (context) {
this.elements = [];//返回值

var type = typeof context;

if (type == ‘function‘) {
addevent(‘load‘, context, window);
} else if (type == ‘string‘) {

var starts = context.substr(0, 1);//跳过0个去一个

var svalue = http://www.mamicode.com/context.substr(1);//跳过一个取所有

switch (starts) {
case "#":
this.elements.push(document.getElementById(svalue));
break;
case ".":
this.elements = getbyglass(svalue);
break;
default:
this.elements = document.getElementsByTagName(context);
break;

}

//return this.elements;
} else if (type == ‘object‘) {
this.elements.push(context);
}
}

DpQuery.prototype.inint.prototype = DpQuery.prototype;

//原型 遍历元素
DpQuery.prototype.each = function (fn) {

for (var i = 0; i < this.elements.length; i++) {
fn(i, this.elements[i]);
}
}

//点击事件
DpQuery.prototype.click = function (fn) {

this.each(function (i, ele) {
addevent(‘click‘, fn, ele);
});
return this;
}

//鼠标按下事件
DpQuery.prototype.mousedown = function (fn) {
this.each(function (i, ele) {
addevent(‘mousedown‘, fn, ele);
});
return this;
}

//鼠标移动事件
DpQuery.prototype.mousemove = function (fn) {
this.each(function (i, ele) {
addevent(‘mousemove‘, fn, ele);
});
return this;
}

//鼠标抬起事件
DpQuery.prototype.mouseup = function (fn) {
this.each(function (i, ele) {
addevent(‘mouseup‘, fn, ele);
});

return this;
}

//鼠标滑上 滑出
DpQuery.prototype.hover = function (fnover, fnout) {
this.each(function (i, ele) {
addevent(‘mouseover‘, fnover, ele);
if (fnout) {
addevent(‘mouseout‘, fnout, ele);
}
});
return this;
}

//轮流切换
DpQuery.prototype.toogage = function () {

var _arguments = arguments;

this.each(function (i, ele) {
addevent(‘click‘, (function () {
var count = 0;
return function () {
_arguments[count % arguments.length]();
count++;
}
})(), ele);
});
}

//获取元素样式或者设置元素样式
DpQuery.prototype.css = function (stylename, stylevalue) {
if (arguments.length == 2) {
this.each(function (i, ele) {
ele.style[stylename] = stylevalue;
});
} else {
return getStyle(this.elements[0], stylename);
}
}

//获取或设置属性
DpQuery.prototype.attr = function (attrname, attrvalue) {
if (attrvalue) {
this.each(function (i, ele) {

ele.setAttribute(attrname, attrvalue);
});
} else {

return this.elements[0].getAttribute(attrname);

}
}
//高
DpQuery.prototype.Height = function (value) {

if (value) {
this.each(function (i, ele) {
ele.style.Height = value + "px";
});
} else {
return getStyle(this.elements[0], "height");
}
}

//宽
DpQuery.prototype.Width = function (value) {

if (value) {
this.each(function (i, ele) {
ele.style.width = value + "px";
});
} else {
return getStyle(this.elements[0], "width");
}
}

//距左边距离
DpQuery.prototype.left = function (value) {
if (!value) {
return getOffset(this.elements[0]).x;
} else {
this.elements[0].style.left = value + "px";
return this;
}

}

//距上边距离
DpQuery.prototype.top = function (value) {
if (!value) {
return getOffset(this.elements[0]).y;
} else {
this.elements[0].style.top = value + "px";
return this;
}

}

//拖拽
DpQuery.prototype.drag = function () {

this.each(function (i, ele) {
$(ele).mousedown(function (e) {

ele.style.position = "absolute";
ele.style["cursor"] = "pointer";

var event = e || event;

var disx = event.clientX - $(ele).left();

var disy = event.clientY - $(ele).top();

document.onmousemove = function (e) {

var event = e || event;

$(ele).left(event.clientX - disx);
$(ele).top(event.clientY - disy);

};

document.onmouseup = function () {

document.onmousemove = null;

document.onmouseup = null;
}

return false;
});
});

return this;
}

window.DpQuery = window.$ = DpQuery;

})(window);

自己实现jquery