ActivityNotFoundException Intents + Widget

Issue

I'm trying to create a Widget which update the text every time I press the save button and get the information from 2 editText. When I press the button to send by Intent the variables it throws

"android.content.ActivityNotFoundException: Unable to find explicit activity class"

in the logcat. Here my code:

Main.class

public class MainActivity extends AppCompatActivity {
    Button save;
    EditText Nom;
    EditText Cognom;

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

        save = (Button) findViewById(R.id.save);
        Nom = (EditText) findViewById(R.id.editTextNom);
        Cognom = (EditText) findViewById(R.id.editTextCognom);

        save.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent i;
                i = new Intent(MainActivity.this, NewAppWidget.class);
                i.putExtra("NOM",Nom.getText().toString());
                i.putExtra("COGNOM",Cognom.getText().toString());
                startActivity(i);
            }
        });
    }
}

WidgetClass

public class NewAppWidget extends AppWidgetProvider {

    static Intent intent = new Intent();

    static String nom = intent.getExtras().getString("NOM");
    static String cognom = intent.getExtras().getString("COGNOM");

    static void updateAppWidget(Context context, AppWidgetManager appWidgetManager,
                                int appWidgetId) {


        CharSequence widgetText = context.getString(R.string.appwidget_text);
        // Construct the RemoteViews object
        RemoteViews views = new RemoteViews(context.getPackageName(), R.layout.new_app_widget);
        views.setTextViewText(R.id.TextViewNom, nom);
        views.setTextViewText(R.id.TextViewCognom, cognom);

        // Instruct the widget manager to update the widget
        appWidgetManager.updateAppWidget(appWidgetId, views);
    }

    @Override
    public void onUpdate(Context context, AppWidgetManager appWidgetManager, int[] appWidgetIds) {
        // There may be multiple widgets active, so update all of them
        for (int appWidgetId : appWidgetIds) {
            updateAppWidget(context, appWidgetManager, appWidgetId);
        }
    }

    @Override
    public void onEnabled(Context context) {
        // Enter relevant functionality for when the first widget is created
    }

    @Override
    public void onDisabled(Context context) {
        // Enter relevant functionality for when the last widget is disabled
    }
}

Manifest:

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

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

        <receiver android:name=".NewAppWidget">
            <intent-filter>
                <action android:name="android.appwidget.action.APPWIDGET_UPDATE" />
            </intent-filter>

            <meta-data
                android:name="android.appwidget.provider"
                android:resource="@xml/new_app_widget_info" />
        </receiver>
    </application>

Error:

android.content.ActivityNotFoundException: Unable to find explicit activity class

Solution

Dude first thing is you can not start an widget provider like an activity.

If you want update widget widget from activity you can do like this.

Intent intent = new Intent(this, MyAppWidgetProvider.class);
intent.setAction(AppWidgetManager.ACTION_APPWIDGET_UPDATE);
// Use an array and EXTRA_APPWIDGET_IDS instead of AppWidgetManager.EXTRA_APPWIDGET_ID,
// since it seems the onUpdate() is only fired on that:
 int[] ids = AppWidgetManager.getInstance(getApplication())
    .getAppWidgetI‌​ds(new ComponentName(getApplication(), MyAppWidgetProvider.class));
intent.putExtra(AppWidgetManager.EXTRA_APPWIDGET_IDS, ids);
sendBroadcast(intent);

You can pass your parameter to this intent or better you save your values in Shared Preference and use it in your widget provider class in onUpdate method.

I read your widgetprovider class, you will get many errors when using this class. For understanding android widget, you can fork and understand this Github sample.

In this sample you will get how to update widget, how to have multiple widget controls and much more. So i strongly recommend you go through this sample.

Answered By - Khemraj Sharma