使用implementation ("com.github.PhilJay:MPAndroidChart:v3.0.2")报错

[chinakaifa]

java.lang.NullPointerException: Attempt to invoke virtual method 'int java.lang.String.length()' on a null object reference at com.github.mikephil.charting.utils.Utils.drawXAxisValue(Utils.java:564) at com.github.mikephil.charting.renderer.XAxisRenderer.drawLabel(XAxisRenderer.java:231) at com.github.mikephil.charting.renderer.XAxisRenderer.drawLabels(XAxisRenderer.java:225) at com.github.mikephil.charting.renderer.XAxisRenderer.renderAxisLabels(XAxisRenderer.java:130) at com.github.mikephil.charting.charts.BarLineChartBase.onDraw(BarLineChartBase.java:251) at android.view.View.draw(View.java:23073) at android.view.View.updateDisplayListIfDirty(View.java:21930) at android.view.ViewGroup.recreateChildDisplayList(ViewGroup.java:4728) at android.view.ViewGroup.dispatchGetDisplayList(ViewGroup.java:4701) at android.view.View.updateDisplayListIfDirty(View.java:21884) at android.view.ViewGroup.recreateChildDisplayList(ViewGroup.java:4728) at android.view.ViewGroup.dispatchGetDisplayList(ViewGroup.java:4701) at android.view.View.updateDisplayListIfDirty(View.java:21884) at android.view.ViewGroup.recreateChildDisplayList(ViewGroup.java:4728) at android.view.ViewGroup.dispatchGetDisplayList(ViewGroup.java:4701) at android.view.View.updateDisplayListIfDirty(View.java:21884) at android.view.ViewGroup.recreateChildDisplayList(ViewGroup.java:4728) at android.view.ViewGroup.dispatchGetDisplayList(ViewGroup.java:4701) at android.view.View.updateDisplayListIfDirty(View.java:21884) at android.view.ViewGroup.recreateChildDisplayList(ViewGroup.java:4728) at android.view.ViewGroup.dispatchGetDisplayList(ViewGroup.java:4701) at android.view.View.updateDisplayListIfDirty(View.java:21884) at android.view.ViewGroup.recreateChildDisplayList(ViewGroup.java:4728) at android.view.ViewGroup.dispatchGetDisplayList(ViewGroup.java:4701) at android.view.View.updateDisplayListIfDirty(View.java:21884) at android.view.ViewGroup.recreateChildDisplayList(ViewGroup.java:4728) at android.view.ViewGroup.dispatchGetDisplayList(ViewGroup.java:4701) at android.view.View.updateDisplayListIfDirty(View.java:21884) at android.view.ViewGroup.recreateChildDisplayList(ViewGroup.java:4728) at android.view.ViewGroup.dispatchGetDisplayList(ViewGroup.java:4701) at android.view.View.updateDisplayListIfDirty(View.java:21884) at android.view.ViewGroup.recreateChildDisplayList(ViewGroup.java:4728) at android.view.ViewGroup.dispatchGetDisplayList(ViewGroup.java:4701) at android.view.View.updateDisplayListIfDirty(View.java:21884) at android.view.ThreadedRenderer.updateViewTreeDisplayList(ThreadedRenderer.java:564) at android.view.ThreadedRenderer.updateRootDisplayList(ThreadedRenderer.java:570) at android.view.ThreadedRenderer.draw(ThreadedRenderer.java:658) at android.view.ViewRootImpl.draw(ViewRootImpl.java:5794) at android.view.ViewRootImpl.performDraw(ViewRootImpl.java:5476) at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:4453) at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:2837) at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:10520) at android.view.Choreographer$CallbackRecord.run(Choreographer.java:1623) at android.view.Choreographer.doCallbacks(Choreographer.java:1141) at android.view.Choreographer.doFrame(Choreographer.java:1012) at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:1585) at android.os.Handler.handleCallback(Handler.java:955) at android.os.Handler.dispatchMessage(Handler.java:102) at android.os.Looper.loopOnce(Looper.java:206) at android.os.Looper.loop(Looper.java:296) at android.app.ActivityThread.main(ActivityThread.java:9000) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:569) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:976)