当我在图表中选择一部分时，我如何获得确切的范围值?

Question

我正在做一个angular应用程序，我正在使用图表库amcharts。我想做一个选择，并获得所选部分的范围。下面是代码:

this.chart.cursor.behavior = "selectX";
this.chart.cursor.events.on("selectended", function(ev) {
var range = ev.target.xRange;
var axis = ev.target.chart.xAxes.getIndex(0);
var from = (axis.getPositionLabel(axis.toAxisPosition(range.start)));
var to = (axis.getPositionLabel(axis.toAxisPosition(range.end)));
alert("Selected from " + from + " to " + to);
});

to和from变量只得到日期而不是完整的日期。p: xaxis是一个日期时间。

Answer 1

您可以使用axis'positionToDate方法从绘制范围的位置获取确切的Date对象值:

this.chart.cursor.behavior = "selectX";
this.chart.cursor.events.on("selectended", function(ev) {
var range = ev.target.xRange;
var axis = ev.target.chart.xAxes.getIndex(0);
var from = (axis.positionToDate(axis.toAxisPosition(range.start)));
var to = (axis.positionToDate(axis.toAxisPosition(range.end)));
alert("Selected from " + from + " to " + to);
});