Question

启动Android应用时，我一直收到错误消息。在添加两个设计和构建数据库的类之前，它工作正常。 logcat消息如下！

12-04 05:39:54.370: D/ActivityThread(25676): setTargetHeapUtilization:0.25
12-04 05:39:54.370: D/ActivityThread(25676): setTargetHeapIdealFree:8388608
12-04 05:39:54.370: D/ActivityThread(25676): setTargetHeapConcurrentStart:2097152
12-04 05:39:54.500: D/AbsListView(25676): Get MotionRecognitionManager
12-04 05:39:54.620: I/Adreno200-EGLSUB(25676): <ConfigWindowMatch:2136>: Format RGBA_8888.
12-04 05:39:54.640: E/(25676): <s3dReadConfigFile:75>: Can't open file for reading
12-04 05:39:54.640: E/(25676): <s3dReadConfigFile:75>: Can't open file for reading
12-04 05:40:05.331: W/dalvikvm(25676): threadid=1: thread exiting with uncaught exception (group=0x4146d438)
12-04 05:40:05.331: E/AndroidRuntime(25676): FATAL EXCEPTION: main
12-04 05:40:05.331: E/AndroidRuntime(25676): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.mamon.pumpitup/com.mamon.pumpitup.AddActivity}: java.lang.ClassCastException: android.widget.Button cannot be cast to android.widget.EditText
12-04 05:40:05.331: E/AndroidRuntime(25676):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2110)
12-04 05:40:05.331: E/AndroidRuntime(25676):    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2135)
12-04 05:40:05.331: E/AndroidRuntime(25676):    at android.app.ActivityThread.access$700(ActivityThread.java:143)
12-04 05:40:05.331: E/AndroidRuntime(25676):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1241)
12-04 05:40:05.331: E/AndroidRuntime(25676):    at android.os.Handler.dispatchMessage(Handler.java:99)
12-04 05:40:05.331: E/AndroidRuntime(25676):    at android.os.Looper.loop(Looper.java:137)
12-04 05:40:05.331: E/AndroidRuntime(25676):    at android.app.ActivityThread.main(ActivityThread.java:4967)
12-04 05:40:05.331: E/AndroidRuntime(25676):    at java.lang.reflect.Method.invokeNative(Native Method)
12-04 05:40:05.331: E/AndroidRuntime(25676):    at java.lang.reflect.Method.invoke(Method.java:511)
12-04 05:40:05.331: E/AndroidRuntime(25676):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1011)
12-04 05:40:05.331: E/AndroidRuntime(25676):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:778)
12-04 05:40:05.331: E/AndroidRuntime(25676):    at dalvik.system.NativeStart.main(Native Method)
12-04 05:40:05.331: E/AndroidRuntime(25676): Caused by: java.lang.ClassCastException: android.widget.Button cannot be cast to android.widget.EditText
12-04 05:40:05.331: E/AndroidRuntime(25676):    at com.mamon.pumpitup.AddActivity.onCreate(AddActivity.java:27)
12-04 05:40:05.331: E/AndroidRuntime(25676):    at android.app.Activity.performCreate(Activity.java:5160)
12-04 05:40:05.331: E/AndroidRuntime(25676):    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1094)
12-04 05:40:05.331: E/AndroidRuntime(25676):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2074)
12-04 05:40:05.331: E/AndroidRuntime(25676):    ... 11 more

Answer 1

java.lang.RuntimeException: Unable to start activity ComponentInfo{com.mamon.pumpitup/com.mamon.pumpitup.AddActivity}: java.lang.ClassCastException: android.widget.Button cannot be cast to android.widget.EditText

在这一行中非常清楚

您正在尝试将Button视图投射到com.mamon.pumpitup.AddActivity类中的EditText视图，您可能引用了错误 R.id.your_view

Answer 2

你正在尝试这样的事情：

Button b = (EditText)findViewById(R.id.source);

你应该写下其中一个，取决于你想要的东西：

Button b = (Button)findViewById(R.id.source);
EditText ed= (EditText)findViewById(R.id.source);

添加数据库类时的Android Logcat错误

2 个答案: