自己写然后xml中提示这里有问题，我还以为是我自己写的哪里写错了。然后把下载的代码直接导入，也是这里有问题。请问到底是啥情况？？？

java.lang.NullPointerException

    at android.graphics.Canvas.throwIfRecycled(Canvas.java:1025)

    at android.graphics.Canvas.drawBitmap(Canvas.java:1127)

    at com.imooc.weixin6_0.ChangeColorIconWithText.onDraw(ChangeColorIconWithText.java:121)

    at android.view.View.draw(View.java:13458)

    at android.view.View.draw(View.java:13342)

    at android.view.ViewGroup.drawChild(ViewGroup.java:2929)

    at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2799)

    at android.view.View.draw(View.java:13461)

    at android.view.View.draw(View.java:13342)

    at android.view.ViewGroup.drawChild(ViewGroup.java:2929)

    at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2799)

    at android.view.View.draw(View.java:13340)

    at android.view.ViewGroup.drawChild(ViewGroup.java:2929)

    at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2799)

    at android.view.View.draw(View.java:13461)

    at android.widget.FrameLayout.draw(FrameLayout.java:467)

    at android.view.View.draw(View.java:13342)

    at android.view.ViewGroup.drawChild(ViewGroup.java:2929)

    at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2799)

    at android.view.View.draw(View.java:13340)

    at android.view.ViewGroup.drawChild(ViewGroup.java:2929)

    at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2799)

    at android.view.View.draw(View.java:13340)

    at android.view.ViewGroup.drawChild(ViewGroup.java:2929)

    at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2799)

    at android.view.View.draw(View.java:13461)

    at android.view.View.draw(View.java:13342)

    at android.view.ViewGroup.drawChild(ViewGroup.java:2929)

    at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2799)

    at android.view.View.draw(View.java:13461)