Pessoal,
Estou fazendo um exemplo simples e como sou iniciante não consigo entender o erro:
O erro ocorre quando executa a seguinte linha:
exemplo4.java final TextView textResultado = (EditText) findViewById(R.id.campoResultado);Tela:
Emulador: The application LivroAndroidCap3 (process br.livro.android.cap3) has stopped unexpectedly. Please try again.
Log cat:
05-27 12:22:16.938: ERROR/AndroidRuntime(1086): FATAL EXCEPTION: main
05-27 12:22:16.938: ERROR/AndroidRuntime(1086): java.lang.RuntimeException: Unable to start activity ComponentInfo{br.livro.android.cap3/br.livro.android.cap3.Exemplo4}: java.lang.ClassCastException: android.widget.TextView
05-27 12:22:16.938: ERROR/AndroidRuntime(1086): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663)
05-27 12:22:16.938: ERROR/AndroidRuntime(1086): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679)
05-27 12:22:16.938: ERROR/AndroidRuntime(1086): at android.app.ActivityThread.access$2300(ActivityThread.java:125)
05-27 12:22:16.938: ERROR/AndroidRuntime(1086): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033)
05-27 12:22:16.938: ERROR/AndroidRuntime(1086): at android.os.Handler.dispatchMessage(Handler.java:99)
05-27 12:22:16.938: ERROR/AndroidRuntime(1086): at android.os.Looper.loop(Looper.java:123)
05-27 12:22:16.938: ERROR/AndroidRuntime(1086): at android.app.ActivityThread.main(ActivityThread.java:4627)
05-27 12:22:16.938: ERROR/AndroidRuntime(1086): at java.lang.reflect.Method.invokeNative(Native Method)
05-27 12:22:16.938: ERROR/AndroidRuntime(1086): at java.lang.reflect.Method.invoke(Method.java:521)
05-27 12:22:16.938: ERROR/AndroidRuntime(1086): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
05-27 12:22:16.938: ERROR/AndroidRuntime(1086): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
05-27 12:22:16.938: ERROR/AndroidRuntime(1086): at dalvik.system.NativeStart.main(Native Method)
05-27 12:22:16.938: ERROR/AndroidRuntime(1086): Caused by: java.lang.ClassCastException: android.widget.TextView
05-27 12:22:16.938: ERROR/AndroidRuntime(1086): at br.livro.android.cap3.Exemplo4.onCreate(Exemplo4.java:19)
05-27 12:22:16.938: ERROR/AndroidRuntime(1086): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
05-27 12:22:16.938: ERROR/AndroidRuntime(1086): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627)
05-27 12:22:16.938: ERROR/AndroidRuntime(1086): … 11 more
05-27 12:34:45.698: ERROR/AndroidRuntime(1116): FATAL EXCEPTION: main
05-27 12:34:45.698: ERROR/AndroidRuntime(1116): java.lang.RuntimeException: Unable to start activity ComponentInfo{br.livro.android.cap3/br.livro.android.cap3.Exemplo4}: java.lang.ClassCastException: android.widget.TextView
05-27 12:34:45.698: ERROR/AndroidRuntime(1116): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663)
05-27 12:34:45.698: ERROR/AndroidRuntime(1116): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679)
05-27 12:34:45.698: ERROR/AndroidRuntime(1116): at android.app.ActivityThread.access$2300(ActivityThread.java:125)
05-27 12:34:45.698: ERROR/AndroidRuntime(1116): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033)
05-27 12:34:45.698: ERROR/AndroidRuntime(1116): at android.os.Handler.dispatchMessage(Handler.java:99)
05-27 12:34:45.698: ERROR/AndroidRuntime(1116): at android.os.Looper.loop(Looper.java:123)
05-27 12:34:45.698: ERROR/AndroidRuntime(1116): at android.app.ActivityThread.main(ActivityThread.java:4627)
05-27 12:34:45.698: ERROR/AndroidRuntime(1116): at java.lang.reflect.Method.invokeNative(Native Method)
05-27 12:34:45.698: ERROR/AndroidRuntime(1116): at java.lang.reflect.Method.invoke(Method.java:521)
05-27 12:34:45.698: ERROR/AndroidRuntime(1116): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
05-27 12:34:45.698: ERROR/AndroidRuntime(1116): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
05-27 12:34:45.698: ERROR/AndroidRuntime(1116): at dalvik.system.NativeStart.main(Native Method)
05-27 12:34:45.698: ERROR/AndroidRuntime(1116): Caused by: java.lang.ClassCastException: android.widget.TextView
05-27 12:34:45.698: ERROR/AndroidRuntime(1116): at br.livro.android.cap3.Exemplo4.onCreate(Exemplo4.java:19)
05-27 12:34:45.698: ERROR/AndroidRuntime(1116): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
05-27 12:34:45.698: ERROR/AndroidRuntime(1116): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627)
05-27 12:34:45.698: ERROR/AndroidRuntime(1116): … 11 more
05-27 12:57:41.489: ERROR/AndroidRuntime(1145): FATAL EXCEPTION: main
05-27 12:57:41.489: ERROR/AndroidRuntime(1145): java.lang.RuntimeException: Unable to start activity ComponentInfo{br.livro.android.cap3/br.livro.android.cap3.Exemplo4}: java.lang.ClassCastException: android.widget.TextView
05-27 12:57:41.489: ERROR/AndroidRuntime(1145): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663)
05-27 12:57:41.489: ERROR/AndroidRuntime(1145): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679)
05-27 12:57:41.489: ERROR/AndroidRuntime(1145): at android.app.ActivityThread.access$2300(ActivityThread.java:125)
05-27 12:57:41.489: ERROR/AndroidRuntime(1145): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033)
05-27 12:57:41.489: ERROR/AndroidRuntime(1145): at android.os.Handler.dispatchMessage(Handler.java:99)
05-27 12:57:41.489: ERROR/AndroidRuntime(1145): at android.os.Looper.loop(Looper.java:123)
05-27 12:57:41.489: ERROR/AndroidRuntime(1145): at android.app.ActivityThread.main(ActivityThread.java:4627)
05-27 12:57:41.489: ERROR/AndroidRuntime(1145): at java.lang.reflect.Method.invokeNative(Native Method)
05-27 12:57:41.489: ERROR/AndroidRuntime(1145): at java.lang.reflect.Method.invoke(Method.java:521)
05-27 12:57:41.489: ERROR/AndroidRuntime(1145): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
05-27 12:57:41.489: ERROR/AndroidRuntime(1145): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
05-27 12:57:41.489: ERROR/AndroidRuntime(1145): at dalvik.system.NativeStart.main(Native Method)
05-27 12:57:41.489: ERROR/AndroidRuntime(1145): Caused by: java.lang.ClassCastException: android.widget.TextView
05-27 12:57:41.489: ERROR/AndroidRuntime(1145): at br.livro.android.cap3.Exemplo4.onCreate(Exemplo4.java:19)
05-27 12:57:41.489: ERROR/AndroidRuntime(1145): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
05-27 12:57:41.489: ERROR/AndroidRuntime(1145): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627)
05-27 12:57:41.489: ERROR/AndroidRuntime(1145): … 11 more
Agradeço qualquer ajuda.