錯誤/ AndroidRuntime（516）：java.lang.RuntimeException：java.lang.ClassCastException：android.widget.TextView

Question

我在開發應用程序時遇到了運行時異常。這是我的LogCat。

11-06 12:56:09.977: INFO/ActivityManager(59): Starting activity: Intent { cmp=balu.android/.CommonNames } 
11-06 12:56:10.096: INFO/CommonNameTable(516): OPening DataBase Connection.... 
11-06 12:56:10.156: INFO/global(516): Default buffer size used in BufferedReader constructor. It would be better to be explicit if an 8k-char buffer is required. 
11-06 12:56:10.156: INFO/CommonNameTable(516): Inserting record... 
11-06 12:56:10.306: INFO/CommonNameTable(516): Inserting record... 
11-06 12:56:10.428: INFO/CommonNameTable(516): Inserting record... 
11-06 12:56:10.546: INFO/CommonNameTable(516): OPening DataBase Connection.... 
11-06 12:56:10.576: DEBUG/AndroidRuntime(516): Shutting down VM 
11-06 12:56:10.576: WARN/dalvikvm(516): threadid=1: thread exiting with uncaught exception (group=0x4001d800) 
11-06 12:56:10.596: ERROR/AndroidRuntime(516): FATAL EXCEPTION: main 
11-06 12:56:10.596: ERROR/AndroidRuntime(516): java.lang.RuntimeException: Unable to start activity ComponentInfo{balu.android/balu.android.CommonNames}: java.lang.ClassCastException: android.widget.TextView 
11-06 12:56:10.596: ERROR/AndroidRuntime(516):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663) 
11-06 12:56:10.596: ERROR/AndroidRuntime(516):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679) 
11-06 12:56:10.596: ERROR/AndroidRuntime(516):  at android.app.ActivityThread.access$2300(ActivityThread.java:125) 
11-06 12:56:10.596: ERROR/AndroidRuntime(516):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033) 
11-06 12:56:10.596: ERROR/AndroidRuntime(516):  at android.os.Handler.dispatchMessage(Handler.java:99) 
11-06 12:56:10.596: ERROR/AndroidRuntime(516):  at android.os.Looper.loop(Looper.java:123) 
11-06 12:56:10.596: ERROR/AndroidRuntime(516):  at android.app.ActivityThread.main(ActivityThread.java:4627) 
11-06 12:56:10.596: ERROR/AndroidRuntime(516):  at java.lang.reflect.Method.invokeNative(Native Method) 
11-06 12:56:10.596: ERROR/AndroidRuntime(516):  at java.lang.reflect.Method.invoke(Method.java:521) 
11-06 12:56:10.596: ERROR/AndroidRuntime(516):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868) 
11-06 12:56:10.596: ERROR/AndroidRuntime(516):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626) 
11-06 12:56:10.596: ERROR/AndroidRuntime(516):  at dalvik.system.NativeStart.main(Native Method) 
11-06 12:56:10.596: ERROR/AndroidRuntime(516): Caused by: java.lang.ClassCastException: android.widget.TextView 
11-06 12:56:10.596: ERROR/AndroidRuntime(516):  at balu.android.CommonNames.onCreate(CommonNames.java:31) 
11-06 12:56:10.596: ERROR/AndroidRuntime(516):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047) 
11-06 12:56:10.596: ERROR/AndroidRuntime(516):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627) 
11-06 12:56:10.596: ERROR/AndroidRuntime(516):  ... 11 more 
11-06 12:56:10.616: WARN/ActivityManager(59): Force finishing activity balu.android/.CommonNames 
11-06 12:56:10.626: WARN/ActivityManager(59): Force finishing activity balu.android/.Select 
11-06 12:56:11.183: WARN/ActivityManager(59): Activity pause timeout for HistoryRecord{450af6e8 balu.android/.CommonNames} 
11-06 12:56:20.036: WARN/ActivityManager(59): Launch timeout has expired, giving up wake lock! 
11-06 12:56:20.125: WARN/ActivityManager(59): Activity idle timeout for HistoryRecord{450af6e8 balu.android/.CommonNames} 
11-06 12:56:21.252: WARN/ActivityManager(59): Activity idle timeout for HistoryRecord{44fd7b98 balu.android/.BabyNamesAppActivity} 
11-06 12:56:26.456: DEBUG/dalvikvm(132): GC_EXPLICIT freed 1211 objects/86976 bytes in 177ms 

我認爲這是問題的根源。

https://github.com/Balu-Varanasi/BabyNamesApp/blob/master/src/balu/android/CommonNameTable.java https://github.com/Balu-Varanasi/BabyNamesApp/blob/master/src/balu/android/CommonNames.java

能否請你幫我解決這個問題？

Answer 1

我知道了：

在CommonNames.java你使用此代碼：

ListView cnListView = (ListView)findViewById(R.id.commonName); 

但R.id.commonName是TextView的。

你的layout.listview只代表了listview的item結構。

您需要創建新的xml，它將使用ListView組件描述Activity的佈局。再經過

super.onCreate(..); 

做

setContentView(R.layout.your_activity_layout_with_list)