extjs曲线 x轴时间和store不一样,就是安装文档demo写的啊

var storeabc = Ext.create('Ext.data.Store', {
    model: 'WeatherPoint',
    data: [
        { temperature: 58, date: new Date(2011, 1, 1, 8) },
        { temperature: 63, date: new Date(2011, 1, 1, 9) },
        { temperature: 73, date: new Date(2011, 1, 1, 10) },
        { temperature: 78, date: new Date(2011, 1, 1, 11) },
        { temperature: 81, date: new Date(2011, 1, 1, 12) }
    ]
});
function constructSWHisChart() {
        var chart_his = Ext.create('Ext.chart.Chart', {
            renderTo: Ext.getBody(),
            store: storeabc,
            width: 450,
            height: 500,
            axes: [{
                title: '水位(m)',
                type: 'Numeric',
                position: 'left',
                fields: ['temperature']
                // grid:true
            }, {
                title: '时间',
                type: 'Time',
                position: 'bottom',
                fields: ['date'],
                groupBy: 'hour',
                dateFormat: 'ga'
            }],
            series: [{
                type: 'line',
                highlight: {
                    size: 7,
                    radius: 7
                },
                axis: 'left',
                xField: 'date',
                yField: 'temperature'
            }]
        });
        var chart_panel = Ext.getCmp('chart_panel_sw_his');
        chart_panel.removeAll();
        chart_panel.add(chart_his);
}