JavaScript水平滑块

Question

我正在尝试为自己的练习/享受的项目编写不带JQuery的水平滑块。

以下是相关代码：

function moveit() {
    "use strict";
    document.getElementById("position").style.left = window.event.clientX + "px";
}

window.onload = function () {
    "use strict";
    findtime();
    document.getElementById("scrollbar").style.width = document.getElementById("thevideo").offsetWidth + "px";
    var mousemove;
    document.getElementById("scrollbar").onclick = function () {
            mousemove = window.setInterval("moveit()", 1000);
    };
    document.getElementById("scrollbar").mouseup = function () {
            window.clearInterval(mousemove);
    };
};

不用说我对此有疑问。 它会在Chrome，Firefox等上不断产生错误：

Uncaught TypeError: Cannot read property 'clientX' of undefined

现在，如果我运行以下代码，则可以正常运行（但对于跟随鼠标的位置没有用）：

document.getElementById("position").style.left = 12 + "px";

HTML如下：

<?php include("header.php"); ?>
            <div>
                    <video id="thevideo">
                            <source src="movie.ogv" type="video/ogg" />
                    </video>
            </div>
            <div>
                    <span id="currenttime" contenteditable="true">0:00</span> / <span id="totaltime"></span>
            </div>
            <div id="scrollbar">
                    <div id="position" draggable="true"></div>
            </div>
<?php include("footer.php"); ?>

Answer 1

这是我前一段时间做的，也许您可​​以根据您的程序进行调整。

var scrollTimer;

function Timer(callback, delay) {
    var timerId, start, remaining = delay;
    this.pause = function() {
        window.clearTimeout(timerId);
        remaining -= new Date() - start;
    };
    this.resume = function() {
        start = new Date();
        timerId = window.setTimeout(callback, remaining);
    };
    this.resume();
}

function scroll(down) {
  var scrollframe = document.getElementById("contentframe");
  var curY = document.all?
    scrollframe.contentWindow.document.body.scrollTop
  : scrollframe.contentWindow.window.pageYOffset;
  var delta = 5;
  var newY = down? curY+delta : curY-delta;
  scrollframe.contentWindow.scrollTo(0,newY);
}

function autoscroll(down) {
  scroll(down);
  scrollTimer = new Timer(function() {
    autoscroll(down);
  }, 20);
}

function stopscroll() {
  scrollTimer.pause();
}

函数scroll（boolean down）导致向上或向下滚动到iframe contentframe的单个delta增量。 计时器用于重复该操作，这是您将如何使用它：

<a href=#>
<img src="scroller/arrowTop.png" title="Scroll Up"
    onMouseOver="autoscroll(false);" onMouseOut="stopscroll();"/>
</a>

希望这可以帮助。

Answer 2

您快要准备好了-标准JS中没有window.event对象。 因此，请使用DOM事件接口 ：

function moveit(e) {
    "use strict";
    document.getElementById("position").style.left = e.clientX + "px";
}

window.onload = function (e) {
    "use strict";
    findtime();
    document.getElementById("scrollbar").style.width = document.getElementById("thevideo").offsetWidth + "px";
    var mousemove;
    document.getElementById("scrollbar").onclick = function () {
            mousemove = window.setInterval(moveit, 1000);
    };
    document.getElementById("scrollbar").mouseup = function () {
            window.clearInterval(mousemove);
    };
};