null - Aplicação Android => Unfortunately projeto has stopped

Olá, estou estudando Android e quero fazer uma simples passagem de parâmetro para outra Activity mas a aplicação é finalizada no emulador e o logCat mostra um Null pointer Exception, alguém pode me ajudar? Classe

public class MainActivity extends Activity {


EditText num1 = (EditText) findViewById(R.id.txtNumber1);
EditText num2 = (EditText) findViewById(R.id.txtNumber2);
String n1= num1.getText().toString();
int numero1 = Integer.parseInt(n1);
String n2= num2.getText().toString();
int numero2 = Integer.parseInt(n1);
int soma=numero1+numero2;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);


        Button bt = (Button) findViewById(R.id.bt1);
        final Intent it = new Intent(this, Cadastros.class);
        bt.setOnClickListener(new Button.OnClickListener() {

            @Override
            public void onClick(View v) {
            it.putExtra("Total", soma);
            startActivity(it);
            }


        });
    }

XML

<?xml version="1.0" encoding="utf-8"?>
<AbsoluteLayout
    android:id="@+id/widget0"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    xmlns:android="http://schemas.android.com/apk/res/android">
<Button
    android:id="@+id/bt1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Click"
    android:gravity="center"
    android:layout_x="134dp"
    android:layout_y="102dp" />

<EditText
    android:id="@+id/txtNumber1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_x="56dp"
    android:layout_y="179dp"
    android:ems="10"
    android:inputType="number" >

    <requestFocus />
</EditText>

<EditText
    android:id="@+id/txtNumber2"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_x="69dp"
    android:layout_y="222dp"
    android:ems="10"
    android:inputType="number" />

</AbsoluteLayout>

Log

06-16 08:09:48.240: D/AndroidRuntime(948): Shutting down VM
06-16 08:09:48.270: W/dalvikvm(948): threadid=1: thread exiting with uncaught exception (group=0x41465730)
06-16 08:09:48.330: E/AndroidRuntime(948): FATAL EXCEPTION: main
06-16 08:09:48.330: E/AndroidRuntime(948): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{br.com.passagemparam/br.com.passagemparam.MainActivity}: java.lang.NullPointerException
06-16 08:09:48.330: E/AndroidRuntime(948):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2137)
06-16 08:09:48.330: E/AndroidRuntime(948):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2261)
06-16 08:09:48.330: E/AndroidRuntime(948):     at android.app.ActivityThread.access$600(ActivityThread.java:141)
06-16 08:09:48.330: E/AndroidRuntime(948):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1256)
06-16 08:09:48.330: E/AndroidRuntime(948):     at android.os.Handler.dispatchMessage(Handler.java:99)
06-16 08:09:48.330: E/AndroidRuntime(948):     at android.os.Looper.loop(Looper.java:137)
06-16 08:09:48.330: E/AndroidRuntime(948):     at android.app.ActivityThread.main(ActivityThread.java:5103)
06-16 08:09:48.330: E/AndroidRuntime(948):     at java.lang.reflect.Method.invokeNative(Native Method)
06-16 08:09:48.330: E/AndroidRuntime(948):     at java.lang.reflect.Method.invoke(Method.java:525)
06-16 08:09:48.330: E/AndroidRuntime(948):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)
06-16 08:09:48.330: E/AndroidRuntime(948):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
06-16 08:09:48.330: E/AndroidRuntime(948):     at dalvik.system.NativeStart.main(Native Method)
06-16 08:09:48.330: E/AndroidRuntime(948): Caused by: java.lang.NullPointerException
06-16 08:09:48.330: E/AndroidRuntime(948):     at android.app.Activity.findViewById(Activity.java:1853)
06-16 08:09:48.330: E/AndroidRuntime(948):     at br.com.passagemparam.MainActivity.<init>(MainActivity.java:14)
06-16 08:09:48.330: E/AndroidRuntime(948):     at java.lang.Class.newInstanceImpl(Native Method)
06-16 08:09:48.330: E/AndroidRuntime(948):     at java.lang.Class.newInstance(Class.java:1130)
06-16 08:09:48.330: E/AndroidRuntime(948):     at android.app.Instrumentation.newActivity(Instrumentation.java:1061)
06-16 08:09:48.330: E/AndroidRuntime(948):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2128)
06-16 08:09:48.330: E/AndroidRuntime(948):     ... 11 more

Cadastro XML

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <TextView
        android:id="@+id/label1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Fala Fera"
        android:textAppearance="?android:attr/textAppearanceLarge" />

    <TextView
        android:id="@+id/mostraTotal"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

</LinearLayout>

String XML

<?xml version="1.0" encoding="utf-8"?>
<resources>

    <string name="app_name">Passagem param</string>
    <string name="hello_world">Hello world!</string>
    <string name="action_settings">Settings</string>

</resources>

Manifest

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="br.com.passagemparam"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="14"
        android:targetSdkVersion="21" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name=".MainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity android:name="Cadastros">
            <intent-filter>
                <action android:name="android.intent.action.MAIN"/>
            </intent-filter>
        </activity>
    </application>

</manifest>

LogCAt

06-16 13:06:43.040: E/AndroidRuntime(859): FATAL EXCEPTION: main
06-16 13:06:43.040: E/AndroidRuntime(859): java.lang.RuntimeException: Unable to start activity ComponentInfo{br.com.passagemparam
/br.com.passagemparam.Cadastros}: android.content.res.Resources$NotFoundException: String resource ID #0x8
06-16 13:06:43.040: E/AndroidRuntime(859):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2211)
06-16 13:06:43.040: E/AndroidRuntime(859):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2261)
06-16 13:06:43.040: E/AndroidRuntime(859):     at android.app.ActivityThread.access$600(ActivityThread.java:141)
06-16 13:06:43.040: E/AndroidRuntime(859):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1256)
06-16 13:06:43.040: E/AndroidRuntime(859):     at android.os.Handler.dispatchMessage(Handler.java:99)
06-16 13:06:43.040: E/AndroidRuntime(859):     at android.os.Looper.loop(Looper.java:137)
06-16 13:06:43.040: E/AndroidRuntime(859):     at android.app.ActivityThread.main(ActivityThread.java:5103)
06-16 13:06:43.040: E/AndroidRuntime(859):     at java.lang.reflect.Method.invokeNative(Native Method)
06-16 13:06:43.040: E/AndroidRuntime(859):     at java.lang.reflect.Method.invoke(Method.java:525)
06-16 13:06:43.040: E/AndroidRuntime(859):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)
06-16 13:06:43.040: E/AndroidRuntime(859):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
06-16 13:06:43.040: E/AndroidRuntime(859):     at dalvik.system.NativeStart.main(Native Method)
06-16 13:06:43.040: E/AndroidRuntime(859): Caused by: android.content.res.Resources$NotFoundException: String resource ID #0x8
06-16 13:06:43.040: E/AndroidRuntime(859):     at android.content.res.Resources.getText(Resources.java:239)
06-16 13:06:43.040: E/AndroidRuntime(859):     at android.widget.TextView.setText(TextView.java:3844)
06-16 13:06:43.040: E/AndroidRuntime(859):     at br.com.passagemparam.Cadastros.onCreate(Cadastros.java:23)
06-16 13:06:43.040: E/AndroidRuntime(859):     at android.app.Activity.performCreate(Activity.java:5133)
06-16 13:06:43.040: E/AndroidRuntime(859):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
06-16 13:06:43.040: E/AndroidRuntime(859):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2175)
06-16 13:06:43.040: E/AndroidRuntime(859):     ... 11 more

Olá, está Ok agora. O problema está na outra Activity que trava, o log mostra:

06-16 10:19:43.485: E/AndroidRuntime(2803): FATAL EXCEPTION: main
06-16 10:19:43.485: E/AndroidRuntime(2803): java.lang.RuntimeException: Unable to start activity ComponentInfo{br.com.passagemparam/br.com.passagemparam.Cadastros}: 
android.content.res.Resources$NotFoundException: String resource ID #0x5

— Jrmanzini 16 de jun de 2015

Classe

public class Cadastros extends MainActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        setContentView(R.layout.cadastros);

        Intent it = getIntent();

        if (it != null) {
            int param = 0;
            int total = it.getIntExtra("Total", param);

             TextView tv = (TextView) findViewById(R.id.mostraTotal);
             tv.setText(total);

        }
}
}

Posta o string.xml, cadastros.xml e o manifest

— A H Gusukuma 16 de jun de 2015

OK, postado. Obrigado

Faltou o AndroidManifest.xml

public static final class string {
        public static final int action_settings=0x7f050002;
        public static final int app_name=0x7f050000;
        public static final int hello_world=0x7f050001;
    }

Estranho, que se eu não usar os TextView funciona:

                 /*  AlertDialog.Builder dialogo = new      AlertDialog.Builder(Cadastros.this);

                dialogo.setTitle("Resultado");

                dialogo.setMessage("Soma: " + total);

                dialogo.setNeutralButton("OK", null);

                dialogo.show();

Deu certo fazendo isso:

 TextView tv = (TextView) findViewById(R.id.mostraTotal);
             tv.setText("Resultado"+total);

Ao invés disso

 TextView tv = (TextView) findViewById(R.id.mostraTotal);
             tv.setText(total);

Aplicação Android => Unfortunately projeto has stopped

Comentário

3 respostas

Comentário

Comentário

Comentário

Não é a resposta que estava procurando? Procure outras perguntas com as tags null exception ou faça a sua própria pergunta.