Question

我尝试创建一个Widget，每当我按下保存按钮并从2 editText获取信息时更新文本。当我按下按钮以通过Intent发送它抛出的变量＆＃34; android.content.ActivityNotFoundException：无法找到显式活动类＆＃34;在logcat中。这是我的代码：

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
    }
}

清单：

 <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>

错误： android.content.ActivityNotFoundException：无法找到显式活动类

Answer 1

AppWidgetProvider延伸BroadcastReceiver 非活动

i = new Intent(MainActivity.this, NewAppWidget.class);
startActivity(i);

要使用startActivity，您需要提供Activity class's child object

NewAppWidget不是活动!!

Answer 2

首先，你不能像活动那样启动小部件提供程序。

如果您想从活动中获取更新小部件小部件，您可以这样做。

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())
    .getAppWidgetI‌ds(new ComponentName(getApplication(), MyAppWidgetProvider.class));
intent.putExtra(AppWidgetManager.EXTRA_APPWIDGET_IDS, ids);
sendBroadcast(intent);

您可以将参数传递给此意图，或者更好地将值保存在Shared Preference中，并在onUpdate方法的widget提供程序类中使用它。

我读了你的widgetprovider类，使用这个类时会遇到很多错误。为了理解android小部件，你可以分叉并理解这个Github sample。

在此示例中，您将了解如何更新窗口小部件，如何使用多个窗口小部件控件等等。所以我强烈建议你仔细阅读这个样本。

ActivityNotFoundException Intents + Widget

2 个答案: