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翻看谷歌源碼那些讓人感興趣的東西--通知的好用功能

來源：程序員人生發(fā)布時間：2016-06-03 18:37:50 閱讀次數(shù)：2601次

轉(zhuǎn)載請注明出處：王亟亟的大牛之路

上周寫完那篇Blog以后就1直做著被分配到的Web任務(wù)，也就沒繼續(xù)捯飭N那些事，然后今天還在看Notification這部份，然后看到了LNotification這個包，讀完源碼以后繼續(xù)給大家做簡單的分析，由于源碼觸及翻墻所以代碼和自己加的注釋丟到Git了

安理下我的收納庫：https://github.com/ddwhan0123/Useful-Open-Source-Android

首先我們來看下這個項目在哪一個目錄下
這里寫圖片描述

地址以下：https://developer.android.com/samples/LNotifications/index.html

跟我們上次的Messaging Service是鄰居。

那我們來看下演示效果（部份）

他在桌面icon也有類似待處理事件的通知
這里寫圖片描述

實現(xiàn)點擊觸發(fā)復(fù)瑣事件和通知排序

這里寫圖片描述

OK，由于是Sample所以好看難看我們不管，我們來看看分別能做甚么，有3個功能塊（都是Fragment）的，1個1個來分析

首先是HeadsUpNotificationFragment（這部份注釋很詳細(xì)了，就不過量分析了）

主要是實現(xiàn)這1點 用戶點擊通知會在Activity Task中生成1個新的實例

/**
 * Fragment that demonstrates options for displaying Heads-Up Notifications.
 * 這類模式下,用戶點擊通知會在Activity Task中生成1個新的實例
 */
public class HeadsUpNotificationFragment extends Fragment {

    /**
     * NotificationId用于從此Fragment的通知。
     */
    private static final int NOTIFICATION_ID = 1;

    private NotificationManager mNotificationManager;

    /**
     * 按鈕用于點擊顯示通知
     */
    private Button mShowNotificationButton;

    /**
     * 如果選中，該Fragment創(chuàng)建的通知將顯示為Heads-Up通知。
     */
    private CheckBox mUseHeadsUpCheckbox;

    /**
     * 使用此工廠方法來創(chuàng)建新實例
     * 該Fragment使用提供的參數(shù)。
     *
     * @return 新的HeadsUpNotificationFragment的實例.
     */
    public static HeadsUpNotificationFragment newInstance() {
        HeadsUpNotificationFragment fragment = new HeadsUpNotificationFragment();
        fragment.setRetainInstance(true);
        return fragment;
    }

    public HeadsUpNotificationFragment() {
        // 空構(gòu)造
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        //初始化NotificationManager
        mNotificationManager = (NotificationManager) getActivity().getSystemService(Context
                .NOTIFICATION_SERVICE);
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // 填充UI
        return inflater.inflate(R.layout.fragment_heads_up_notification, container, false);
    }

    @Override
    public void onViewCreated(View view, Bundle savedInstanceState) {
        super.onViewCreated(view, savedInstanceState);
        mShowNotificationButton = (Button) view.findViewById(R.id.show_notification_button);
        //點擊按鈕就Toast1段話,告知用戶已觸發(fā)點擊事件
        mShowNotificationButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                mNotificationManager.notify(NOTIFICATION_ID, createNotification(
                        mUseHeadsUpCheckbox.isChecked()));
                Toast.makeText(getActivity(), "Show Notification clicked", Toast.LENGTH_SHORT).show();
            }
        });
        mUseHeadsUpCheckbox = (CheckBox) view.findViewById(R.id.use_heads_up_checkbox);
    }

    /**
     * 創(chuàng)建1個新的取決于參數(shù)的通知。
     *
     * @param makeHeadsUpNotification 1個布爾值判斷是不是通知將作為heads-up通知來創(chuàng)建。
     *                                <ul>
     *                                <li>true :  heads-up通知</li>
     *                                <li>false : 普統(tǒng)統(tǒng)知</li>
     *                                </ul>
     * @return 1個Notification 實例.
     */
    //@VisibleForTesting
    Notification createNotification(boolean makeHeadsUpNotification) {
        //這里就是1些普通的配置
        Notification.Builder notificationBuilder = new Notification.Builder(getActivity())
                .setSmallIcon(R.drawable.ic_launcher_notification)
                .setPriority(Notification.PRIORITY_DEFAULT)
                .setCategory(Notification.CATEGORY_MESSAGE)
                .setContentTitle("Sample Notification")
                .setContentText("This is a normal notification.");
        //如果是heads-up通知
        if (makeHeadsUpNotification) {
            Intent push = new Intent();
            push.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
            push.setClass(getActivity(), LNotificationActivity.class);

            PendingIntent fullScreenPendingIntent = PendingIntent.getActivity(getActivity(), 0,
                    push, PendingIntent.FLAG_CANCEL_CURRENT);
            notificationBuilder
                    .setContentText("Heads-Up Notification on Android L or above.")
                    .setFullScreenIntent(fullScreenPendingIntent, true);
        }
        return notificationBuilder.build();
    }
}

然后是 VisibilityMetadataFragment

**主要行動是在鎖屏條件下Notification的各種現(xiàn)實情況，Public Private Secret
可應(yīng)對與所需的1些業(yè)務(wù)場景，諸如需要輸入1些pin 密碼甚么的才可以做操作的功能**

/**
 * Fragment that demonstrates how notifications with different visibility metadata differ on
 * a lockscreen.
 *在鎖屏情況下不同的通知,默許PUBLIC
 */
public class VisibilityMetadataFragment extends Fragment {

    private NotificationManager mNotificationManager;

    /**
     * {@link RadioGroup} that has Visibility RadioButton in its children.
     */
    //用于選擇模式
    private RadioGroup mRadioGroup;

    /**
     * 構(gòu)建不同的ID,讓他被區(qū)分對待
     */
    private Integer mIncrementalNotificationId = Integer.valueOf(0);

    /**
     * 按鈕,顯示通知用
     */
    private Button mShowNotificationButton;

    /**
     * 使用此工廠方法來創(chuàng)建使用提供的參數(shù)，該Fragment的新實例。
     *
     * @return 1個新的NotificationFragment的實例.
     */
    public static VisibilityMetadataFragment newInstance() {
        VisibilityMetadataFragment fragment = new VisibilityMetadataFragment();
        fragment.setRetainInstance(true);
        return fragment;
    }

    public VisibilityMetadataFragment() {
        // Required empty public constructor
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        mNotificationManager = (NotificationManager) getActivity().getSystemService(Context
                .NOTIFICATION_SERVICE);
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        return inflater.inflate(R.layout.fragment_visibility_metadata_notification, container, false);
    }

    @Override
    public void onViewCreated(View view, Bundle savedInstanceState) {
        super.onViewCreated(view, savedInstanceState);
        mShowNotificationButton = (Button) view.findViewById(R.id.show_notification_button);
        mShowNotificationButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                NotificationVisibility visibility = getVisibilityFromSelectedRadio(mRadioGroup);
                showNotificationClicked(visibility);
            }
        });
        mRadioGroup = (RadioGroup) view.findViewById(R.id.visibility_radio_group);
    }

    /**
     * 創(chuàng)建1個具有不同級別可視性的通知。
     *
     * @param visibility 要創(chuàng)建的通知的可見性
     * @return 通知的實例.
     */
    //@VisibleForTesting
    Notification createNotification(NotificationVisibility visibility) {
        Notification.Builder notificationBuilder = new Notification.Builder(getActivity())
                .setContentTitle("Notification for Visibility metadata");

        notificationBuilder.setVisibility(visibility.getVisibility());
        notificationBuilder.setContentText(String.format("Visibility : %s",
                visibility.getDescription()));
        notificationBuilder.setSmallIcon(visibility.getNotificationIconId());

        return notificationBuilder.build();
    }

    /**
     * Returns a {@link NotificationVisibility} depending on which RadioButton in the radiogroup
     * is selected.
     *
     * @param radiogroup The RadioGroup.
     * @return The instance of {@link NotificationVisibility} corresponding to RadioButton.
     */
    private NotificationVisibility getVisibilityFromSelectedRadio(RadioGroup radiogroup) {
        switch (radiogroup.getCheckedRadioButtonId()) {
            case R.id.visibility_public_radio_button:
                return NotificationVisibility.PUBLIC;
            case R.id.visibility_private_radio_button:
                return NotificationVisibility.PRIVATE;
            case R.id.visibility_secret_radio_button:
                return NotificationVisibility.SECRET;
            default:
                //If not selected, returns PUBLIC as default.
                return NotificationVisibility.PUBLIC;
        }
    }

    /**
     * Invoked when {@link #mShowNotificationButton} is clicked.
     * Creates a new notification with a different visibility level.
     *
     * @param visibility The visibility of the notification to be created.
     */
    private void showNotificationClicked(NotificationVisibility visibility) {
        // Assigns a unique (incremented) notification ID in order to treat each notification as a
        // different one. This helps demonstrate how a notification with a different visibility
        // level differs on the lockscreen.
        mIncrementalNotificationId = new Integer(mIncrementalNotificationId + 1);
        mNotificationManager.notify(mIncrementalNotificationId, createNotification(visibility));
        Toast.makeText(getActivity(), "Show Notification clicked", Toast.LENGTH_SHORT).show();
    }

    /**
     * Enum indicating possible visibility levels for notifications and related data(String
     * representation of visibility levels, an icon ID to create a notification) to
     * create a notification.
     */
    //@VisibleForTesting
     enum NotificationVisibility {
        PUBLIC(Notification.VISIBILITY_PUBLIC, "Public", R.drawable.ic_public_notification),
        PRIVATE(Notification.VISIBILITY_PRIVATE, "Private", R.drawable.ic_private_notification),
        SECRET(Notification.VISIBILITY_SECRET, "Secret", R.drawable.ic_secret_notification);

        /**
         * Visibility level of the notification.
         */
        private final int mVisibility;

        /**
         * String representation of the visibility.
         */
        private final String mDescription;

        /**
         * Id of an icon used for notifications created from the visibility.
         */
        private final int mNotificationIconId;

        NotificationVisibility(int visibility, String description, int notificationIconId) {
            mVisibility = visibility;
            mDescription = description;
            mNotificationIconId = notificationIconId;
        }

        public int getVisibility() {
            return mVisibility;
        }

        public String getDescription() {
            return mDescription;
        }

        public int getNotificationIconId() {
            return mNotificationIconId;
        }
    }
}

還有個就是我們截圖中的類OtherMetadataFragment

他可以根據(jù)用戶操作做1些列諸如郵件，電話，鬧鐘提示等功能，并對通知進行輕重緩急的排序

/**
 * Fragment that demonstrates how to attach metadata introduced in Android L, such as
 * priority data, notification category and person data.
 * 通知列表會根據(jù)優(yōu)先級高低進行排序
 */
public class OtherMetadataFragment extends Fragment {

    private static final String TAG = OtherMetadataFragment.class.getSimpleName();

    /**
     * 用于采摘聯(lián)系人要求的代碼。
     */
    public static final int REQUEST_CODE_PICK_CONTACT = 1;

    /**
     * Incremental Integer used for ID for notifications so that each notification will be
     * treated differently.
     * 構(gòu)建不同的ID,讓他被區(qū)分對待
     */
    private Integer mIncrementalNotificationId = Integer.valueOf(0);

    private NotificationManager mNotificationManager;

    /**
     * 按鈕,顯示通知用
     */
    private Button mShowNotificationButton;

    /**
     * Spinner that holds possible categories used for a notification as
     * {@link Notification.Builder#setCategory(String)}.
     * 設(shè)置類型的下拉選擇欄
     */
    private Spinner mCategorySpinner;

    /**
     * Spinner that holds possible priorities used for a notification as
     * {@link Notification.Builder#setPriority(int)}.
     * 設(shè)置優(yōu)先級的下拉選擇欄
     */
    private Spinner mPrioritySpinner;

    /**
     * Holds a URI for the person to be attached to the notification.
     * 持有的URI的人要附加到該通知。
     */
    //@VisibleForTesting
    Uri mContactUri;

    /**
     * 使用此工廠方法來創(chuàng)建使用提供的參數(shù)，該Fragment的新實例。
     *
     * @return 1個新的NotificationFragment的實例.
     */
    public static OtherMetadataFragment newInstance() {
        OtherMetadataFragment fragment = new OtherMetadataFragment();
        fragment.setRetainInstance(true);
        return fragment;
    }

    public OtherMetadataFragment() {
        // Required empty public constructor
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        mNotificationManager = (NotificationManager) getActivity().getSystemService(Context
                .NOTIFICATION_SERVICE);
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        return inflater.inflate(R.layout.fragment_other_metadata, container, false);
    }

    @Override
    public void onViewCreated(View view, Bundle savedInstanceState) {
        super.onViewCreated(view, savedInstanceState);
        mShowNotificationButton = (Button) view.findViewById(R.id.show_notification_button);
        mShowNotificationButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                //往spinner里填東西,然后發(fā)送通知
                Priority selectedPriority = (Priority) mPrioritySpinner.getSelectedItem();
                Category selectedCategory = (Category) mCategorySpinner.getSelectedItem();
                showNotificationClicked(selectedPriority, selectedCategory, mContactUri);
            }
        });
        //填充數(shù)據(jù)
        mCategorySpinner = (Spinner) view.findViewById(R.id.category_spinner);
        ArrayAdapter<Category> categoryArrayAdapter = new ArrayAdapter<Category>(getActivity(),
                android.R.layout.simple_spinner_item, Category.values());
        categoryArrayAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        mCategorySpinner.setAdapter(categoryArrayAdapter);

        mPrioritySpinner = (Spinner) view.findViewById(R.id.priority_spinner);
        ArrayAdapter<Priority> priorityArrayAdapter = new ArrayAdapter<Priority>(getActivity(),
                android.R.layout.simple_spinner_item, Priority.values());
        priorityArrayAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        mPrioritySpinner.setAdapter(priorityArrayAdapter);

        view.findViewById(R.id.attach_person).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                findContact();
            }
        });

        view.findViewById(R.id.contact_entry).setVisibility(View.GONE);
    }

    @Override
    public void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        switch (requestCode) {
            case REQUEST_CODE_PICK_CONTACT:
                if (resultCode == Activity.RESULT_OK) {
                    Uri contactUri = data.getData();
                    mContactUri = contactUri;
                    updateContactEntryFromUri(contactUri);
                }
                break;
        }
    }

    /**
     * Invoked when {@link #mShowNotificationButton} is clicked.
     * Creates a new notification and sets metadata passed as arguments.
     *
     * @param priority   The priority metadata.
     * @param category   The category metadata.
     * @param contactUri The URI to be added to the new notification as metadata.
     * @return A Notification instance.
     */
    //@VisibleForTesting
    Notification createNotification(Priority priority, Category category, Uri contactUri) {
        Notification.Builder notificationBuilder = new Notification.Builder(getActivity())
                .setContentTitle("Notification with other metadata")
                .setSmallIcon(R.drawable.ic_launcher_notification)
                .setPriority(priority.value)
                .setCategory(category.value)
                .setContentText(String.format("Category %s, Priority %s", category.value,
                        priority.name()));
        if (contactUri != null) {
            notificationBuilder.addPerson(contactUri.toString());
            Bitmap photoBitmap = loadBitmapFromContactUri(contactUri);
            if (photoBitmap != null) {
                notificationBuilder.setLargeIcon(photoBitmap);
            }
        }
        return notificationBuilder.build();
    }

    /**
     * Invoked when {@link #mShowNotificationButton} is clicked.
     * Creates a new notification and sets metadata passed as arguments.
     *
     * @param priority   The priority metadata.
     * @param category   The category metadata.
     * @param contactUri The URI to be added to the new notification as metadata.
     */
    private void showNotificationClicked(Priority priority, Category category, Uri contactUri) {
        // Assigns a unique (incremented) notification ID in order to treat each notification as a
        // different one. This helps demonstrate how a priority flag affects ordering.
        mIncrementalNotificationId = new Integer(mIncrementalNotificationId + 1);
        mNotificationManager.notify(mIncrementalNotificationId, createNotification(priority,
                category, contactUri));
        Toast.makeText(getActivity(), "Show Notification clicked", Toast.LENGTH_SHORT).show();
    }

    private void findContact() {
        Intent intent = new Intent(Intent.ACTION_PICK, ContactsContract.Contacts.CONTENT_URI);
        startActivityForResult(intent, REQUEST_CODE_PICK_CONTACT);
    }

    /**
     * Returns a {@link Bitmap} from the Uri specified as the argument.
     *
     * @param contactUri The Uri from which the result Bitmap is created.
     * @return The {@link Bitmap} instance retrieved from the contactUri.
     */
    private Bitmap loadBitmapFromContactUri(Uri contactUri) {
        if (contactUri == null) {
            return null;
        }
        Bitmap result = null;
        Cursor cursor = getActivity().getContentResolver().query(contactUri, null, null, null,
                null);
        if (cursor != null && cursor.moveToFirst()) {
            int idx = cursor.getColumnIndex(ContactsContract.Contacts.PHOTO_ID);
            String hasPhoto = cursor.getString(idx);
            Uri photoUri = Uri.withAppendedPath(contactUri, ContactsContract.Contacts.Photo
                    .CONTENT_DIRECTORY);
            if (hasPhoto != null) {
                try {
                    result = MediaStore.Images.Media.getBitmap(getActivity().getContentResolver()
                            , photoUri);
                } catch (IOException e) {
                    Log.e(TAG, String.format("Failed to load resource. Uri %s", photoUri), e);
                }
            } else {
                Drawable defaultContactDrawable = getActivity().getResources().getDrawable(R
                        .drawable.ic_contact_picture);
                result = ((BitmapDrawable) defaultContactDrawable).getBitmap();
            }
        }
        return result;
    }

    /**
     * Updates the Contact information on the screen when a contact is picked.
     *
     * @param contactUri The Uri from which the contact is retrieved.
     */
    private void updateContactEntryFromUri(Uri contactUri) {
        Cursor cursor = getActivity().getContentResolver().query(contactUri, null, null, null,
                null);
        if (cursor != null && cursor.moveToFirst()) {
            int idx = cursor.getColumnIndex(ContactsContract.Contacts.DISPLAY_NAME);
            String name = cursor.getString(idx);
            idx = cursor.getColumnIndex(ContactsContract.Contacts.PHOTO_ID);
            String hasPhoto = cursor.getString(idx);

            Uri photoUri = Uri.withAppendedPath(contactUri, ContactsContract.Contacts.Photo
                    .CONTENT_DIRECTORY);
            ImageView contactPhoto = (ImageView) getActivity().findViewById(R.id.contact_photo);
            if (hasPhoto != null) {
                contactPhoto.setImageURI(photoUri);
            } else {
                Drawable defaultContactDrawable = getActivity().getResources().getDrawable(R
                        .drawable.ic_contact_picture);
                contactPhoto.setImageDrawable(defaultContactDrawable);
            }
            TextView contactName = (TextView) getActivity().findViewById(R.id.contact_name);
            contactName.setText(name);

            getActivity().findViewById(R.id.contact_entry).setVisibility(View.VISIBLE);
            getActivity().findViewById(R.id.attach_person).setVisibility(View.GONE);
            getActivity().findViewById(R.id.click_to_change).setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                    findContact();
                }
            });
            Log.i(TAG, String.format("Contact updated. Name %s, PhotoUri %s", name, photoUri));
        }
    }

    /**
     * Enum indicating possible categories in {@link Notification} used from
     * {@link #mCategorySpinner}.
     */
     enum Category {
        ALARM("alarm"),
        CALL("call"),
        EMAIL("email"),
        ERROR("err"),
        EVENT("event"),
        MESSAGE("msg"),
        PROGRESS("progress"),
        PROMO("promo"),
        RECOMMENDATION("recommendation"),
        SERVICE("service"),
        SOCIAL("social"),
        STATUS("status"),
        SYSTEM("sys"),
        TRANSPORT("transport");

        private final String value;

        Category(String value) {
            this.value = value;
        }

        @Override
        public String toString() {
            return value;
        }
    }

    /**
     * Enum indicating possible priorities in {@link Notification} used from
     * {@link #mPrioritySpinner}.
     */
    //@VisibleForTesting
     enum Priority {
        DEFAULT(Notification.PRIORITY_DEFAULT),
        MAX(Notification.PRIORITY_MAX),
        HIGH(Notification.PRIORITY_HIGH),
        LOW(Notification.PRIORITY_LOW),
        MIN(Notification.PRIORITY_MIN);

        private final int value;

        Priority(int value) {
            this.value = value;
        }
    }
}

這部份的代碼比較長，沒有對每部份進行翻譯OR解釋，在這里大致描寫下。
首先聲明了2個枚舉，1個操作類型，1個操作排序的次序。

測試的時候分別對，默許，最高和最低進行了測試，結(jié)果也如大家所看到的，最高就會在最上面，最低就出現(xiàn)在通知欄最下面了，然后就是行動類型，用戶在產(chǎn)生通知之前需要選擇他的行動類型和該類型所需的1些參數(shù)諸如通訊錄聯(lián)系人的號碼啊，郵箱地址甚么的，有些需要圖片操作的源碼里也做了相應(yīng)實現(xiàn)大家需要的可以調(diào)用就好了。（由于測試機沒通訊錄，所以沒有測的很深，大家可以自己插卡試試，這部份如何暫時保存意見，但是排序是絕對有效的）

以上是對這個包里3個實現(xiàn)Fragment的簡單分析，然后提1下注意點，使用處景在安卓 L 就是棒棒糖版本版本太低的有問題就是自己適配了。

最重要的1點是這些通知都會在桌面的利用 ICON產(chǎn)生 1 2 3這類未讀數(shù)的統(tǒng)計

源碼地址：https://github.com/ddwhan0123/BlogSample/blob/master/LNotifications.zip?raw=true

謝謝各位觀眾老爺，有問題可以微信M我（活人不是公眾號）

這里寫圖片描述