33 lines
1.4 KiB
JavaScript
33 lines
1.4 KiB
JavaScript
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function FloatDiv(id) {
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this.ID = id;
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this.ObjMove = document.getElementById(id);
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this.LastScrollY = 0; // 已经移动
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FloatDiv.prototype.Move = function (obj) {
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var scrollTop;
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if (document.documentElement && document.documentElement.scrollTop)
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scrollTop = document.documentElement.scrollTop;
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else if (document.body)
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scrollTop = document.body.scrollTop;
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var percent; // 本次移动像素
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percent = (scrollTop - obj.LastScrollY) * 0.1; // 每次移动10%
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if (percent > 0) percent = Math.ceil(percent); // 截掉小数，数字会变大
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else percent = Math.floor(percent); // 截掉小数，数字会变小
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obj.ObjMove.style.top = parseInt(obj.ObjMove.style.top) + percent + 'px';
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obj.LastScrollY = obj.LastScrollY + percent;
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};
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FloatDiv.prototype.Init = function (obj) {
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if (!obj.ObjMove) {
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alert('对象不存在');
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return;
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}
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window.setInterval(this.BindInterval(this.Move, obj), 10);
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};
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// 绑定参数，window.setInterval，不能指定参数，需要绑定
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FloatDiv.prototype.BindInterval = function (funcName) {
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var args = [];
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for (var i = 1; i < arguments.length; i++) {
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args.push(arguments[i]);
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}
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return function () { funcName.apply(this, args); }
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};
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}
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