带复选框且支持搜索功能的下拉列表13-优快云博客

本文介绍了一种实现下拉列表展开与隐藏的方法，包括显示与隐藏列表、响应鼠标滚轮及点击事件等关键功能。

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// private
    getParams : function(q)
    {
        var p = {};
        //p[this.queryParam] = q;
        if (this.pageSize)
        {
            p.start = 0;
            p.limit = this.pageSize;
        }
        return p;
    },
    /**
     * Hides the dropdown list if it is currently expanded. Fires the 'collapse' event on completion.
     */
    collapse : function()
    {
        if (!this.isExpanded())
        {
            return;
        }
        this.list.hide();
        Ext.getDoc().un('mousewheel', this.collapseIf, this);
        Ext.getDoc().un('mousedown', this.collapseIf, this);
        this.fireEvent('collapse', this);
    },
    // private
    collapseIf : function(e)
    {
        if (!e.within(this.wrap) && !e.within(this.list))
        {
            this.collapse();
        }
    },

    /**
     * Expands the dropdown list if it is currently hidden. Fires the 'expand' event on completion.
     */
    expand : function()
    {
        if (this.isExpanded() || !this.hasFocus)
        {
            return;
        }
        this.list.alignTo(this.wrap, this.listAlign);
        var hvalueArray = this.hiddenField.value.split(this.valueSeparator);
        for (var i = 0; i < this.store.data.length; i++)
        {
            var r = this.store.getAt(i);
            var newValue = r.data[this.displayField];
            var v = r.data[this.valueField];
            for (var j = 0; j < hvalueArray.length; j++)
            {
                if (hvalueArray[j] == v)
                {
                    document.getElementById("checkBox_" + newValue).className = "checked";
                }
            }

        }
        this.list.show();
        Ext.getDoc().on('mousewheel', this.collapseIf, this);
        Ext.getDoc().on('mousedown', this.collapseIf, this);
        this.fireEvent('expand', this);
    },