我使用YAxisRenderer
解决了自己的问题。我设置了一个自定义YAxisRenderer
,并更改了computeAxisValues
功能以适合自己的需求。这是我的代码:
import Charts
class TimelineYAxisRender: YAxisRenderer{
/// Sets up the axis values. Computes the desired number of labels between the two given extremes.
@objc open override func computeAxisValues(min: Double, max: Double)
{
super.computeAxisValues(min: min, max: max)
guard let axis = self.axis else { return }
let labelCount = axis.labelCount
let range = max - min
// Ensure stops contains at least n elements.
axis.entries.removeAll(keepingCapacity: true)
axis.entries.reserveCapacity(labelCount)
let lowestHour = Int((min/60).rounded(.down))
let highestHour = Int((max/60).rounded(.up))
let rangeHour = highestHour - lowestHour
switch range {
case 160..<600:
for i in 0...2 * rangeHour{
axis.entries.append(Double(i) * 30 + Double(lowestHour * 60))
}
case 50..<160:
for i in 0...4 * rangeHour{
axis.entries.append(Double(i) * 15 + Double(lowestHour * 60))
}
case 15..<50:
for i in 0...12 * rangeHour{
axis.entries.append(Double(i) * 5 + Double(lowestHour * 60))
}
case 0..<15:
for i in 0...60 * rangeHour{
axis.entries.append(Double(i) + Double(lowestHour * 60))
}
default:
for i in 0...8{
axis.entries.append(Double(i) * 180)
}
}
}
}
我的将左y轴设置为新YAxisRenderer
的代码:
let transformer = barChart.getTransformer(forAxis:.left)
let viewPortHandler = barChart.leftYAxisRenderer.viewPortHandler
barChart.leftYAxisRenderer = TimelineYAxisRender(viewPortHandler: viewPortHandler, yAxis: barChart.leftAxis, transformer: transformer)
我使用了舍入系统,因此我只加载用户可以看到的图形部分的标签,因为加载每个标签会占用过多的内存并导致模拟器结结。我还使用max-min来确定要加载哪些标签以创建平滑缩放。加载新标签时,可以通过更改开关盒的参数来更改,并且可以通过更改实际附加到axis.entries
的内容来更改缩放量。