谁能告诉我这个运行时错误背后的原因是什么?
java.lang.RuntimeException: Unable to instantiate activity ComponentInfo Caused by: java.lang.InstantiationException
我正在尝试在 GitHub 上按照 Joe Blough 的 Android PDF 查看器库制作 PDF 阅读器应用程序:https ://github.com/jblough/Android-Pdf-Viewer-Library 。我遵循了一切,最终出现了这个错误。
12-20 03:43:14.037: E/AndroidRuntime(29822): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.traininghandouts.app/com.traininghandouts.app.PdfViewer}: java.lang.InstantiationException: com.traininghandouts.app.PdfViewer
12-20 03:43:14.037: E/AndroidRuntime(29822): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2585)
12-20 03:43:14.037: E/AndroidRuntime(29822): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679)
12-20 03:43:14.037: E/AndroidRuntime(29822): at android.app.ActivityThread.access$2300(ActivityThread.java:125)
12-20 03:43:14.037: E/AndroidRuntime(29822): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033)
12-20 03:43:14.037: E/AndroidRuntime(29822): at android.os.Handler.dispatchMessage(Handler.java:99)
12-20 03:43:14.037: E/AndroidRuntime(29822): at android.os.Looper.loop(Looper.java:123)
12-20 03:43:14.037: E/AndroidRuntime(29822): at android.app.ActivityThread.main(ActivityThread.java:4627)
12-20 03:43:14.037: E/AndroidRuntime(29822): at java.lang.reflect.Method.invokeNative(Native Method)
12-20 03:43:14.037: E/AndroidRuntime(29822): at java.lang.reflect.Method.invoke(Method.java:521)
12-20 03:43:14.037: E/AndroidRuntime(29822): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
12-20 03:43:14.037: E/AndroidRuntime(29822): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
12-20 03:43:14.037: E/AndroidRuntime(29822): at dalvik.system.NativeStart.main(Native Method)
12-20 03:43:14.037: E/AndroidRuntime(29822): Caused by: java.lang.InstantiationException: com.traininghandouts.app.PdfViewer
12-20 03:43:14.037: E/AndroidRuntime(29822): at java.lang.Class.newInstanceImpl(Native Method)
12-20 03:43:14.037: E/AndroidRuntime(29822): at java.lang.Class.newInstance(Class.java:1429)
12-20 03:43:14.037: E/AndroidRuntime(29822): at android.app.Instrumentation.newActivity(Instrumentation.java:1021)
12-20 03:43:14.037: E/AndroidRuntime(29822): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2577)
12-20 03:43:14.037: E/AndroidRuntime(29822): ... 11 more
这是我的代码:
try{
String path = "mnt/sdcard/android-android-ui-design-patterns.pdf";
Intent intent = new Intent(this, PdfViewer.class);
intent.putExtra(PdfViewerActivity.EXTRA_PDFFILENAME, path);
startActivity(intent);
}catch(Exception e){
e.printStackTrace();
}