我正在为我的笔记应用程序开发小部件。

我要归档的类似于colorNote widget:

1. 选择笔记应用程序小部件

2. 允许用户选择存储在 Sqlite 中的可用笔记列表

3. 显示带有所选笔记内容的小部件。

我可以显示简单的小部件来显示我想要的简单消息，但我想要做的是允许用户从笔记列表中选择一个指定的笔记作为小部件的内容。我很难找到相关资源，如果您知道某个搜索关键字，请告诉我，我会自己进行研究。

最佳答案

我认为 ColorNote 使用的是 Widget Configuration Activity 。 您可以在第一个链接(官方链接)或(为什么不)找到有用的示例 there。

要实现“对话框”样式，您必须像这样设置小部件配置 Activity :

<activity
 ...
 android:theme="@android:style/Theme.Dialog"
 android:excludeFromRecents="true" />

上面的例子取自 this answer 。

如果您想了解更多关于小部件设计的信息，请查看 there。

示例

1) 创建widget_info 并将其放在res/xml 文件夹中:

<?xml version="1.0" encoding="utf-8"?>
<appwidget-provider xmlns:android="http://schemas.android.com/apk/res/android"
    android:configure="com.mycompany.app.widgettest.WidgetConfigureActivity"
    android:initialKeyguardLayout="@layout/widget"
    android:initialLayout="@layout/widget"
    android:minHeight="40dp"
    android:minWidth="40dp"
    android:resizeMode="horizontal|vertical"
    android:updatePeriodMillis="86400000"
    android:widgetCategory="home_screen">

</appwidget-provider>

2) 创建您的小部件布局(我选择了最简单的布局):

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#09C"
    android:padding="@dimen/widget_margin">

    <TextView
        android:id="@+id/appwidget_text"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:layout_centerVertical="true"
        android:layout_margin="8dp"
        android:background="#09C"
        android:contentDescription="@string/appwidget_text"
        android:text="@string/appwidget_text"
        android:textColor="#ffffff"
        android:textSize="24sp"
        android:textStyle="bold|italic" />

</RelativeLayout>

随意赋予它自己的风格。

3) 创建widget_configure Activity 布局:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical"
    android:padding="16dp">

    <TextView
        android:id="@+id/text_view"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginBottom="8dp"
        android:text="@string/configure" />

    <EditText
        android:id="@+id/appwidget_text"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:inputType="text"
        android:layout_below="@+id/text_view"/>

    <ListView
        android:id="@+id/list"
        android:layout_height="wrap_content"
        android:layout_width="match_parent"
        android:layout_below="@+id/appwidget_text"
        android:layout_above="@+id/add_button">
    </ListView>

    <Button
        android:id="@+id/add_button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="8dp"
        android:text="@string/add_widget"
        android:layout_alignParentBottom="true" />

</RelativeLayout>

此外，由您决定样式和编辑 Activity 的布局；在上面的示例中，我添加了一个编辑文本，它将创建一个"new"注释(但它没有保存在数据库中)和一个包含虚拟内容的列表。由您来填充您的列表，当然是从您的数据库中获取的。

4) 将小部件配置 Activity 和小部件提供程序添加到您的 list 中(在 application 标记内):

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

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

        <activity
            android:name=".WidgetConfigureActivity"
            android:theme="@android:style/Theme.Dialog"
            android:excludeFromRecents="true">
            <intent-filter>
                <action android:name="android.appwidget.action.APPWIDGET_CONFIGURE" />
            </intent-filter>
        </activity>

5) 创建将扩展 AppWidgetProvider 的 AppWidget 类(注意应用程序小部件配置在以下类 WidgetConfigureActivity 中实现和管理)[我没有在此类中添加任何特殊内容]:

import android.appwidget.AppWidgetProvider;
import android.appwidget.AppWidgetManager;
import android.content.Context;
import android.widget.RemoteViews;

/**
 * Implementation of App Widget functionality.
 */
public class AppWidget extends AppWidgetProvider {

    @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 onDeleted(Context context, int[] appWidgetIds) {
        // When the user deletes the widget, delete the preference associated with it.
        for (int appWidgetId : appWidgetIds) {
            WidgetConfigureActivity.deleteTitlePref(context, 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
    }

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

        CharSequence widgetText = WidgetConfigureActivity.loadTitlePref(context, appWidgetId);
        // Construct the RemoteViews object
        RemoteViews views = new RemoteViews(context.getPackageName(), R.layout.widget);
        views.setTextViewText(R.id.appwidget_text, widgetText);

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

6) 最后，这是 WidgetConfigureActivity:

import android.app.Activity;
import android.appwidget.AppWidgetManager;
import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.EditText;
import android.widget.ListView;

/**
 * The configuration screen for the {@link AppWidget} com.bepatient.app.widgettest.AppWidget.
 */
public class WidgetConfigureActivity extends Activity {

    int mAppWidgetId = AppWidgetManager.INVALID_APPWIDGET_ID;
    EditText mAppWidgetText;
    private static final String PREFS_NAME = "AppWidget";
    private static final String PREF_PREFIX_KEY = "appwidget";

    public WidgetConfigureActivity() {
        super();
    }

    @Override
    public void onCreate(Bundle icicle) {
        super.onCreate(icicle);

        // Set the result to CANCELED.  This will cause the widget host to cancel
        // out of the widget placement if the user presses the back button.
        setResult(RESULT_CANCELED);

        setContentView(R.layout.widget_configure);
        // Set layout size of activity
        getWindow().setLayout(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT);
        mAppWidgetText = (EditText) findViewById(R.id.appwidget_text);
        findViewById(R.id.add_button).setOnClickListener(mOnClickListener);
        final ListView listView = (ListView) findViewById(R.id.list);

        // Defined array values to show in ListView
        String[] values = new String[] { "Don't forget the milk!",
                "Do not forget to go get the mother-in-law",
                "Go to the laundry",
                "Marise number 0123456789"
        };

        ArrayAdapter<String> adapter = new ArrayAdapter<>(this,
                android.R.layout.simple_list_item_1, android.R.id.text1, values);

        listView.setAdapter(adapter);

        // ListView Item Click Listener
        listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                // Take ListView clicked item value
                String  widgetText    = (String) listView.getItemAtPosition(position);
                createWidget(getApplicationContext(), widgetText);
            }
        });

        // Find the widget id from the intent.
        Intent intent = getIntent();
        Bundle extras = intent.getExtras();
        if (extras != null) {
            mAppWidgetId = extras.getInt(
                    AppWidgetManager.EXTRA_APPWIDGET_ID, AppWidgetManager.INVALID_APPWIDGET_ID);
        }

        // If this activity was started with an intent without an app widget ID, finish with an error.
        if (mAppWidgetId == AppWidgetManager.INVALID_APPWIDGET_ID) {
            finish();
            return;
        }

        mAppWidgetText.setText(loadTitlePref(WidgetConfigureActivity.this, mAppWidgetId));
    }

    View.OnClickListener mOnClickListener = new View.OnClickListener() {
        public void onClick(View v) {
            final Context context = WidgetConfigureActivity.this;

            // When the button is clicked, get text
            String widgetText = mAppWidgetText.getText().toString();
            createWidget(context, widgetText);
        }
    };

    private void createWidget(Context context, String widgetText) {
        // Store the string locally
        saveTitlePref(context, mAppWidgetId, widgetText);

        // It is the responsibility of the configuration activity to update the app widget
        AppWidgetManager appWidgetManager = AppWidgetManager.getInstance(context);
        AppWidget.updateAppWidget(context, appWidgetManager, mAppWidgetId);

        // Make sure we pass back the original appWidgetId
        Intent resultValue = new Intent();
        resultValue.putExtra(AppWidgetManager.EXTRA_APPWIDGET_ID, mAppWidgetId);
        setResult(RESULT_OK, resultValue);
        finish();
    }

    // Write the prefix to the SharedPreferences object for this widget
    static void saveTitlePref(Context context, int appWidgetId, String text) {
        SharedPreferences.Editor prefs = context.getSharedPreferences(PREFS_NAME, 0).edit();
        prefs.putString(PREF_PREFIX_KEY + appWidgetId, text);
        prefs.apply();
    }

    // Read the prefix from the SharedPreferences object for this widget.
    // If there is no preference saved, get the default from a resource
    static String loadTitlePref(Context context, int appWidgetId) {
        SharedPreferences prefs = context.getSharedPreferences(PREFS_NAME, 0);
        String titleValue = prefs.getString(PREF_PREFIX_KEY + appWidgetId, null);
        if (titleValue != null) {
            return titleValue;
        } else {
            return context.getString(R.string.appwidget_text);
        }
    }

    static void deleteTitlePref(Context context, int appWidgetId) {
        SharedPreferences.Editor prefs = context.getSharedPreferences(PREFS_NAME, 0).edit();
        prefs.remove(PREF_PREFIX_KEY + appWidgetId);
        prefs.apply();
    }
}

在本类(class)中，您将必须管理和填充保存在应用数据库中的所有笔记。当您单击按钮或项目时，createWidget 方法将为您完成工作。

注意下面一行:

// Set layout size of activity
getWindow().setLayout(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT);

这必须在 setContentView() 方法之后调用，否则您的 Activity 会很小。如果你运行这个例子，你会发现配置 Activity 有一个简单的风格，所以你必须根据你的应用程序 UI 创建你自己的风格(如果你想要的话!)。

关于java - 如何创建带有选项的 Android 小部件？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/34588501/