绘制背景报空指针异常

[swnnn]

1.问题描述：执行BackgroundCountDown的onDraw方法canvas.drawRoundRect绘制圆角背景时，报java.lang.NullPointerException: Attempt to read from field 'float android.graphics.RectF.left' on a null object reference
2.由于是线上问题，且没有有效的mapping文件，所以并不能定位复现该问题，问题出现在4.4、5.0、6.0
、7.0等机型上，覆盖面比较广
3.通过阅读源代码，并不能找到手动把mHourBgBorderRectF、mHourBgRectF等变量置为null的逻辑
4.附上布局文件如下：
<xxx.countdownview.CountdownView
android:id="@+id/hc_recommend_countdown"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
android:layout_marginRight="10dp"
app:isHideTimeBackground="false"
app:isShowDay="false"
app:isShowHour="true"
app:isShowMillisecond="false"
app:isShowMinute="true"
app:isShowSecond="true"
app:isShowTimeBgDivisionLine="false"
app:suffix=":"
app:suffixHourRightMargin="2dp"
app:suffixMinuteRightMargin="2dp"
app:isTimeTextBold="true"
app:isSuffixTextBold="true"
app:suffixLRMargin="1dp"
app:suffixGravity="center"
app:suffixTextColor="#ffa14d"
app:suffixTextSize="14sp"
app:timeBgColor="#FFa14d"
app:timeTextColor="#FFFFFF"
app:timeBgSize="20dp"
app:timeBgRadius="4dp"
app:timeTextSize="14sp" />

[yudapiandroid]

错误是在绘制背景的时候出现的~
据说是硬件加速的问题~
关闭硬件加速，尝试了几种办法都没解决~
我这边是测试到了 4.x 的时候有问题。
做了两种情况：
1、4.x 不绘制背景 5.x 绘制背景
2、绘制的时候try
@OverRide
protected void onDraw(Canvas canvas) {
setLayerType(View.LAYER_TYPE_SOFTWARE,null);
try {
super.onDraw(canvas);
}catch (Exception e){
DynamicConfig.Builder builder = new DynamicConfig.Builder();
builder.setBackgroundInfo(null);
dynamicShow(builder.build());
super.onDraw(canvas);
}
}

[swnnn]

我查看了下我们的工程配置，发现没有主动开启硬件加速功能，所以他应该是默认关闭的，请问下，您是怎么测试能出现这个问题呢，能把报错的日志粘贴出来吗，我在测试的时候一直没有出现这个问题~~

[swnnn]

然后我发现有个问题，首次初始化CountDownView的时候，会调用多次BackgroundCountDown的onMeasure()方法，就会执行多次initTimeBgRect()方法，在该方法中就会创建多个rectf对象，这个地方有没有可能有问题呢

[chemin233]

首次进入这个页面没有问题,但是第二次进入这个页面就会报这个错,魅族 note6

[message]: Attempt to read from field 'float android.graphics.RectF.left' on a null object reference;
[LocalizedMessage]: Attempt to read from field 'float android.graphics.RectF.left' on a null object reference;
[stacktrace]: java.lang.NullPointerException: Attempt to read from field 'float android.graphics.RectF.left' on a null object reference
at android.graphics.Canvas.drawRoundRect(Canvas.java:1400)
at cn.iwgang.countdownview.BackgroundCountdown.onDraw(BackgroundCountdown.java:321)
at cn.iwgang.countdownview.CountdownView.onDraw(CountdownView.java:91)
at android.view.View.draw(View.java:17304)
at android.view.View.updateDisplayListIfDirty(View.java:16282)
at android.view.View.draw(View.java:17066)
at android.view.ViewGroup.drawChild(ViewGroup.java:3727)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:3513)
at android.view.View.draw(View.java:17307)
at android.view.View.updateDisplayListIfDirty(View.java:16282)
at android.view.View.draw(View.java:17066)
at android.view.ViewGroup.drawChild(ViewGroup.java:3727)
at android.support.v7.widget.RecyclerView.drawChild(RecyclerView.java:4400)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:3513)
at android.view.View.draw(View.java:17307)
at android.support.v7.widget.RecyclerView.draw(RecyclerView.java:3792)
at android.view.View.updateDisplayListIfDirty(View.java:16282)
at android.view.View.draw(View.java:17066)
at android.view.ViewGroup.drawChild(ViewGroup.java:3727)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:3513)
at android.view.View.updateDisplayListIfDirty(View.java:16277)
at android.view.View.draw(View.java:17066)
at android.view.ViewGroup.drawChild(ViewGroup.java:3727)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:3513)
at android.view.View.draw(View.java:17307)
at android.view.View.updateDisplayListIfDirty(View.java:16282)
at android.view.View.draw(View.java:17066)
at android.view.ViewGroup.drawChild(ViewGroup.java:3727)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:3513)
at android.view.View.updateDisplayListIfDirty(View.java:16277)
at android.view.View.draw(View.java:17066)
at android.view.ViewGroup.drawChild(ViewGroup.java:3727)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:3513)
at android.view.View.updateDisplayListIfDirty(View.java:16277)
at android.view.View.draw(View.java:17066)
at android.view.ViewGroup.drawChild(ViewGroup.java:3727)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:3513)
at android.view.View.updateDisplayListIfDirty(View.java:16277)
at android.view.View.draw(View.java:17066)
at android.view.ViewGroup.drawChild(ViewGroup.java:3727)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:3513)
at android.view.View.updateDisplayListIfDirty(View.java:16277)
at android.view.View.draw(View.java:17066)
at android.view.ViewGroup.drawChild(ViewGroup.java:3727)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:3513)
at android.view.View.updateDisplayListIfDirty(View.java:16277)
at android.view.View.draw(View.java:17066)
at android.view.ViewGroup.drawChild(ViewGroup.java:3727)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:3513)
at android.view.View.draw(View.java:17307)
at com.android.internal.policy.DecorView.draw(DecorView.java:789)
at android.view.View.updateDisplayListIfDirty(View.java:16282)
at android.view.ThreadedRenderer.updateViewTreeDisplayList(ThreadedRenderer.java:648)
at android.view.ThreadedRenderer.updateRootDisplayList(ThreadedRenderer.java:654)
at android.view.ThreadedRenderer.draw(ThreadedRenderer.java:762)
at android.view.ViewRootImpl.draw(ViewRootImpl.java:2835)
at android.view.ViewRootImpl.performDraw(ViewRootImpl.java:2637)
at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:2241)
at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1276)
at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:6477)
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:888)
at android.view.Choreograph