java.lang.IllegalArgumentException

 android 使用SweepGradient实现渐变圆弧，报错

使用

val sweepGradient = SweepGradient(0f, 0f, mInnerProgressColors, floatArrayOf(0.0f,aqi / mMaxAqi))
mInnerProgressShader = sweepGradient

 报错： color and position arrays must be of equal length

2021-07-07 09:19:57.974 31230-31230/com.xxx E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.xxx, PID: 31230
    java.lang.IllegalArgumentException: color and position arrays must be of equal length
        at android.graphics.SweepGradient.<init>(SweepGradient.java:97)
        at android.graphics.SweepGradient.<init>(SweepGradient.java:63)
        at com.xxx.widget.AqiDashboardView.setAirQuality(AqiDashboardView.kt:168)
        at com.xxx.AirQualityFragment.refreshAirCircleView(AirQualityFragment.kt:286)
        at com.xxx.AirQualityFragment.refreshAllView(AirQualityFragment.kt:427)
        at com.xxx.AirQualityFragment.onVisibleToUser$lambda-5(AirQualityFragment.kt:250)
        at com.xxx.AirQualityFragment.lambda$0Lfa2xxRhVFNzo7mSNxMIlpcjJ0(Unknown Source:0)
        at com.xxx.-$$Lambda$AirQualityFragment$0Lfa2xxRhVFNzo7mSNxMIlpcjJ0.run(Unknown Source:2)
        at android.os.Handler.handleCallback(Handler.java:883)
        at android.os.Handler.dispatchMessage(Handler.java:100)
        at android.os.Looper.loop(Looper.java:237)
        at android.app.ActivityThread.main(ActivityThread.java:7860)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1075)

看源码：

可以看到，是因为colors 和 positions长度不一致造成的异常。

后来一看，确实是自己设置错了

而positons的size是2，这就造成了上面的异常。所以，把这两个统一起来就好了。

当然，可以只传colors，positions传null，这样colors可以随意长度。