我正在使用图表3.1.1,我无法弄清楚如何使图表始终显示x轴网格线:
在此示例中,我希望图表在4月25日之后显示xAxis网格线和标签,即4月26日,4月27日,4月28日,4月29日,4月30日,5月1日。
我创建了这个类来生成足够的日期,以便在我想要显示的每个后续日期没有数据点时填充空白:
class AxisValuesGenerator: NSObject {
var days: [String]? = []
func generatexAxisDates(liftEvents: [LiftEvent]) -> [String]? {
var dates: [Date] = []
let intervalBetweenDates: TimeInterval = 3600 * 24 // 3600 = 1 hour
let firstDate = (liftEvents.first?.date)! // - intervalBetweenDates
var lastDate = liftEvents.last?.date
if Double(liftEvents.count) < 7 {
let daysToAdd = intervalBetweenDates * Double(7 - liftEvents.count)
lastDate = lastDate?.addingTimeInterval(daysToAdd)
for _ in 0...6 {
dates = self.intervalDates(from: firstDate, to: lastDate!, with: intervalBetweenDates)
}
} else {
dates = self.intervalDates(from: firstDate, to: lastDate!, with: intervalBetweenDates)
}
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "MMM d"
days = dates.map {dateFormatter.string(from: $0)}
return days
}
func intervalDates(from startDate: Date, to endDate:Date, with interval:TimeInterval) -> [Date] {
guard interval > 0 else { return [] }
var dates:[Date] = [startDate]
var currentDate = startDate
while currentDate <= endDate {
currentDate = currentDate.addingTimeInterval(interval)
dates.append(currentDate)
}
return dates
}
它会生成我想要的日期:
▿ Optional<Array<String>> ▿ some : 7 elements
- 0 : "Apr 25"
- 1 : "Apr 26"
- 2 : "Apr 27"
- 3 : "Apr 28"
- 4 : "Apr 29"
- 5 : "Apr 30"
- 6 : "May 1"
- 7 : "May 2"
但图表不会显示它们。
如何让图表显示缺失的网格线?
更新:
我已尝试设置setVisibleXRange
和setLabelCount
(强制),如下所示:
chartView.setVisibleXRange(minXRange: 2.0, maxXRange: 6.0)
let leftAxis = chartView.leftAxis
leftAxis.setLabelCount(7, force: true)
如果我有6个或更多要绘制的值,图表会正确呈现。但你可以看到,只有2个值,我可以强制行,但xAxis标签是错误的: