如何在Flot图形中显示包含数据点数据的弹出窗口?

This example 显示如何启用工具提示(如果单击“启用工具提示”复选框)。下面是使用示例代码的起点:

<script  id="source" language="javascript" type="text/javascript">
$(function () {
var data = [[1251756000000, 122.68],[1251842400000, 122.68],[1251928800000, 125.13],[1252015200000, 112.62],[1252101600000, 122.76]]
$.plot($("#graph_placeholder"), [ data ], {
    xaxis: { mode: "time", minTickSize: [1, "day"], timeformat : "%y/%m/%d", },
    lines: { show: true },
    points: { show: true },
    grid: { hoverable: true },
} );
});

var previousPoint = null;
$("#graph_placeholder").bind("plothover", function (event, pos, item) {
if (item) {
    if (previousPoint != item.datapoint) {
        previousPoint = item.datapoint;
        $("#tooltip").remove();
        showTooltip(item.pageX, item.pageY, '(' + item.datapoint[0] + ', ' + item.datapoint[1]+')');
    }
} else {
    $("#tooltip").remove();
    previousPoint = null;
}
});

function showTooltip(x, y, contents) {
    $('<div id="tooltip">' + contents + '</div>').css( {
        position: 'absolute',
        display: 'none',
        top: y + 5,
        left: x + 5,
        border: '1px solid #fdd',
        padding: '2px',
        'background-color': '#fee',
        opacity: 0.80
    }).appendTo("body").fadeIn(200);
}
</script>