简易拖放效果-优快云博客

本文链接：https://blog.youkuaiyun.com/bob007/article/details/6545247

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
<title>简易拖放效果</title>
</head>

<body>

<script>

var isIE = (document.all) ? true : false;

var $ = function (id) {
    return "string" == typeof id ? document.getElementById(id) : id;
};

var Class = {
    create: function() {
        return function() { this.initialize.apply(this, arguments); }
    }
}

var Extend = function(destination, source) {
    for (var property in source) {
        destination[property] = source[property];
    }
}

var Bind = function(object, fun) {
    return function() {
        return fun.apply(object, arguments);
    }
}

var BindAsEventListener = function(object, fun) {
    return function(event) {
        return fun.call(object, (event || window.event));
    }
}

function addEventHandler(oTarget, sEventType, fnHandler) {
    if (oTarget.addEventListener) {
        oTarget.addEventListener(sEventType, fnHandler, false);
    } else if (oTarget.attachEvent) {
        oTarget.attachEvent("on" + sEventType, fnHandler);
    } else {
        oTarget["on" + sEventType] = fnHandler;
    }
};

function removeEventHandler(oTarget, sEventType, fnHandler) {
    if (oTarget.removeEventListener) {
        oTarget.removeEventListener(sEventType, fnHandler, false);
    } else if (oTarget.detachEvent) {
        oTarget.detachEvent("on" + sEventType, fnHandler);
    } else {
        oTarget["on" + sEventType] = null;
    }
};

//拖放程序
var SimpleDrag = Class.create();
SimpleDrag.prototype = {
//拖放对象,触发对象
initialize: function(drag) {
    this.Drag = $(drag);
    this._x = this._y = 0;
    this._fM = BindAsEventListener(this, this.Move);
    this._fS = Bind(this, this.Stop);
    this.Drag.style.position = "absolute";
    addEventHandler(this.Drag, "mousedown", BindAsEventListener(this, this.Start));
},
//准备拖动
Start: function(oEvent) {
    this._x = oEvent.clientX - this.Drag.offsetLeft;
    this._y = oEvent.clientY - this.Drag.offsetTop;
    addEventHandler(document, "mousemove", this._fM);
    addEventHandler(document, "mouseup", this._fS);
},
//拖动
Move: function(oEvent) {
    this.Drag.style.left = oEvent.clientX - this._x + "px";
    this.Drag.style.top = oEvent.clientY - this._y + "px";
},
//停止拖动
Stop: function() {
    removeEventHandler(document, "mousemove", this._fM);
    removeEventHandler(document, "mouseup", this._fS);
}
};

</script>

<div id="idDrag" style="border:5px solid #0000FF; background:#C4E3FD; width:50px; height:50px;"></div>

<script>
new SimpleDrag("idDrag");
</script>

</body>
</html>

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