achartengine演示的预算表没有按预期工作

Question

我从这里下载achartengine演示：http://code.google.com/p/achartengine/downloads/list 和我开始演示后，我发现不是每个图表都按预期绘制，当我点击预算饼图时，它没有工作，在这里打破了 是我的日志：

06-11 17:48:31.478: D/AndroidRuntime(1909): Shutting down VM 
06-11 17:48:31.478: W/dalvikvm(1909): threadid=1: thread exiting with uncaught exception (group=0x40a221f8) 
06-11 17:48:31.518: E/AndroidRuntime(1909): FATAL EXCEPTION: main 
06-11 17:48:31.518: E/AndroidRuntime(1909): java.lang.NullPointerException 
06-11 17:48:31.518: E/AndroidRuntime(1909):  at android.view.GLES20Canvas.drawBitmap(GLES20Canvas.java:692) 
06-11 17:48:31.518: E/AndroidRuntime(1909):  at android.view.GLES20RecordingCanvas.drawBitmap(GLES20RecordingCanvas.java:103) 
06-11 17:48:31.518: E/AndroidRuntime(1909):  at org.achartengine.GraphicalView.onDraw(GraphicalView.java:174) 
06-11 17:48:31.518: E/AndroidRuntime(1909):  at android.view.View.draw(View.java:10982) 
06-11 17:48:31.518: E/AndroidRuntime(1909):  at android.view.View.getDisplayList(View.java:10421) 
06-11 17:48:31.518: E/AndroidRuntime(1909):  at android.view.ViewGroup.drawChild(ViewGroup.java:2850) 
06-11 17:48:31.518: E/AndroidRuntime(1909):  at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2489) 
06-11 17:48:31.518: E/AndroidRuntime(1909):  at android.view.View.draw(View.java:10985) 
06-11 17:48:31.518: E/AndroidRuntime(1909):  at android.widget.FrameLayout.draw(FrameLayout.java:450) 
06-11 17:48:31.518: E/AndroidRuntime(1909):  at android.view.View.getDisplayList(View.java:10421) 
06-11 17:48:31.518: E/AndroidRuntime(1909):  at android.view.ViewGroup.drawChild(ViewGroup.java:2850) 
06-11 17:48:31.518: E/AndroidRuntime(1909):  at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2489) 
06-11 17:48:31.518: E/AndroidRuntime(1909):  at android.view.View.getDisplayList(View.java:10419) 
06-11 17:48:31.518: E/AndroidRuntime(1909):  at android.view.ViewGroup.drawChild(ViewGroup.java:2850) 
06-11 17:48:31.518: E/AndroidRuntime(1909):  at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2489) 
06-11 17:48:31.518: E/AndroidRuntime(1909):  at android.view.View.draw(View.java:10985) 
06-11 17:48:31.518: E/AndroidRuntime(1909):  at android.widget.FrameLayout.draw(FrameLayout.java:450) 
06-11 17:48:31.518: E/AndroidRuntime(1909):  at com.android.internal.policy.impl.PhoneWindow$DecorView.draw(PhoneWindow.java:2126) 
06-11 17:48:31.518: E/AndroidRuntime(1909):  at android.view.View.getDisplayList(View.java:10421) 
06-11 17:48:31.518: E/AndroidRuntime(1909):  at android.view.HardwareRenderer$GlRenderer.draw(HardwareRenderer.java:840) 
06-11 17:48:31.518: E/AndroidRuntime(1909):  at android.view.ViewRootImpl.draw(ViewRootImpl.java:1935) 
06-11 17:48:31.518: E/AndroidRuntime(1909):  at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1659) 
06-11 17:48:31.518: E/AndroidRuntime(1909):  at android.view.ViewRootImpl.handleMessage(ViewRootImpl.java:2467) 
06-11 17:48:31.518: E/AndroidRuntime(1909):  at android.os.Handler.dispatchMessage(Handler.java:99) 
06-11 17:48:31.518: E/AndroidRuntime(1909):  at android.os.Looper.loop(Looper.java:137) 
06-11 17:48:31.518: E/AndroidRuntime(1909):  at android.app.ActivityThread.main(ActivityThread.java:4424) 
06-11 17:48:31.518: E/AndroidRuntime(1909):  at java.lang.reflect.Method.invokeNative(Native Method) 
06-11 17:48:31.518: E/AndroidRuntime(1909):  at java.lang.reflect.Method.invoke(Method.java:511) 
06-11 17:48:31.518: E/AndroidRuntime(1909):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784) 
06-11 17:48:31.518: E/AndroidRuntime(1909):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551) 
06-11 17:48:31.518: E/AndroidRuntime(1909):  at dalvik.system.NativeStart.main(Native Method) 

我不能赶上在代码中的异常详细信息，也许是因为异常没有在主thread.does发生的人有相同的经历吗？ 任何相关的答案是欢迎，提前谢谢！

Answer 1

这可能与AChartEngine本身的演示应用程序本身没有直接关系。不过，我发现在使用ProGuard的发布模式下构建应用程序（使用AChartEngine库）时。正如ProGuard的android文档中所述，有些情况很难分析并错误地删除它认为未使用的代码。在这种情况下，当库试图通过调用onDraw绘制图形时，它会抛出一个NPE。

为了克服这个问题，我发现你必须自定义ProGuard配置，指示它通过向proguard.cfg添加以下行来单独离开AChartEngine类。

-keep class javax.** { *; } 

希望这可以帮助别人。