如何使用JavaScript调用此函数？

Question

我只是处理基本级别的javascripts.今天我找到了以下内容,并在新数据添加到DIV时向下滚动DIV层.我无法理解如何调用该函数.它是否可以使用window.onload功能？或任何其他.我应该在哪里声明DIV名称？

代码如下.

var chatscroll = new Object();
chatscroll.Pane = 
    function(scrollContainerId)
    {
        this.bottomThreshold = 25;
        this.scrollContainerId = scrollContainerId;
    }

chatscroll.Pane.prototype.activeScroll = 
    function()
    {
        var scrollDiv = document.getElementById(this.scrollContainerId);
        var currentHeight = 0;

        if (scrollDiv.scrollHeight > 0)
            currentHeight = scrollDiv.scrollHeight;
        else 
            if (objDiv.offsetHeight > 0)
                currentHeight = scrollDiv.offsetHeight;

        if (currentHeight - scrollDiv.scrollTop - ((scrollDiv.style.pixelHeight) ? scrollDiv.style.pixelHeight : scrollDiv.offsetHeight) < this.bottomThreshold)
            scrollDiv.scrollTop = currentHeight;

        scrollDiv = null;
    }

更新1:

<script type="text/javascript">
    var chatscroll = new Object();
    var chatScrollPane = new chatscroll.Pane('div1');
    chatScrollPane.activeScroll()
    chatscroll.Pane = function (scrollContainerId) {
    this.bottomThreshold = 25;
    this.scrollContainerId = scrollContainerId;
}
    chatscroll.Pane.prototype.activeScroll = function () {
    var scrollDiv = document.getElementById(this.scrollContainerId);
    var currentHeight = 0;

    if (scrollDiv.scrollHeight > 0)
        currentHeight = scrollDiv.scrollHeight;
    else
        if (objDiv.offsetHeight > 0)
            currentHeight = scrollDiv.offsetHeight;

    if (currentHeight - scrollDiv.scrollTop - ((scrollDiv.style.pixelHeight) ? scrollDiv.style.pixelHeight : scrollDiv.offsetHeight) < this.bottomThreshold)
        scrollDiv.scrollTop = currentHeight;
    scrollDiv = null;
}
</script>

Answer 1

chatscroll.Pane旨在用作构造函数.您将构建一个这样的实例:

new chatscroll.Pane('somescrollContainerId');

如果将返回值分配给变量,则返回值将变为可重用.

var chatScrollPane = new chatscroll.Pane('somescrollContainerId');

在scrollContainerId你传递将是ID(id的属性)DIV,你想使用这个对象的HTML文档中的元素.

你不应该在你的声明中声明它window.onload,但肯定不会受到伤害.所有构造函数做的是创建一个新的对象,设置this值到新的对象,创建和设置bottomThreshold和scrollContainerId属性在其中,那么当构造完成后返回这个新对象.

只需确保activeScroll在文档完全解析之后才调用该函数,因为它实际上会进入您的文档以检索和操作元素.