개발환경 : VS Code

Health Connect 를 열심히 로컬 환경에서 개발하고, 이제 PlayStore 내부테스트로 테스트를 시작하려는 순간! 

이런 메세지를 마주하게 될 것이다. 

앱이 헬스 커넥트에 엑세스할 수 없음
앱이 최신 상태인지 확인하거나 앱 개발자에게 지원을 문의하세요. 

This app can't access Health Connect
Check the app is up-to-date, or contract the app developer for support.

이 때, 우리가 간과한 것이 있으니!  자주 묻는 질문(FAQ) 까지 정독하지 않은 것 즉,  제일 중요한 "개발자 선언 양식"을 작성하여 요청 해야한다는 것!!

What is Health Connect?

Health Connect is a health data platform for Android app developers. It provides a single, consolidated interface for access to users' health & wellness data, and consistent functional behavior across all devices. With Health Connect, users have a secure health & wellness data storage on-device, with full control and transparency over access.

How does Health Connect work?

Health Connect supports more than 50 common health & fitness data types and categories, including: activity, sleep, nutrition, body measurements and vitals like heart rate and blood pressure.

With user permission, developers can securely read from and write data to Health Connect, using standardized schemas and API behavior. Users will have full control over their privacy settings, with granular controls to see which apps are requesting access to data at any given time. The data in Health Connect is stored on-device and encrypted. Users will have the ability to shut off access or delete data they don't want on their device, and the option to prioritize one data source over another when using multiple apps.

Health Connect Architecture

The following is an explanation of Health Connect's key aspects and architectural components:

• Client app - to integrate with Health Connect, the client app first links then SDK into their health and fitness app. This provides an API surface to interact with the Health Connect API.
• Software Development Kit - the SDK enables the client app to communicate with the Health Connect APK over IPC.
• Health Connect APK - this is the APK that implements Health Connect. It contains both its Permissions Management and Data Management components. The Health Connect APK is made available directly on the user's device, making Health Connect device-centric instead of account-centric.
• Permissions management - Health Connect includes a user interface through which apps request the user's permission to display data. It also provides a list of existing user permissions. This allows users to easily control and manage the access they have granted or denied to various applications.
• Data management - Health Connect provides a user interface with an overview of recorded data, whether it's a user's step counts, cycling speeds, heart rate, or other supported data types.

What you'll build

In this codelab, you're going to build a simple Health and Fitness app integrated with Health Connect. Your app will:

• Obtain and check user permissions for data access
• Write data to Health Connect
• Read aggregated data from Health Connect

What you'll learn

• How to setup your environment to support Health Connect integration development
• How to obtain permissions and execute permission checks
• How to contribute health & fitness data to the Health Connect platform
• How to benefit from the on-device data storage
• How to validate your app with Google provided developer tools

What you'll need

• Latest stable version of Android Studio
• Android mobile device with Android SDK version 28 (Pie) or higher

Mobile apps with HTML, CSS & JS Target multiple platforms with one code base Free and open source

웹 베이스로 하이브리드 앱을 만들기 위한 프레임워크 중 하나로 Apache Software Foundation 에서 만들고 있다. 라이센스는 당연히 Apache License, Version 2.0.

요즘 계속 Native만 작업했는데, 오랜만에 이런 하이브리드 환경을 접하게 되었다. 

잘해보자구! 

Signos streamlines integrations with other health and fitness apps through a single Health Connect API

Posted by the Android Team

Signos helps people make healthier decisions and achieve their health goals by giving them a simple way to track and monitor their body’s response to glucose throughout the day. Pairing a continuous glucose monitor with an AI-driven app, Signos builds an understanding of a member's metabolic profile in real time, providing personalized nutrition suggestions based on their glucose patterns. This includes determining which foods are best for a member and when to eat them, or when to exercise to bring glucose levels back within a healthy range for optimal weight loss.

The Signos team knew that having more context on a member’s daily lifestyle behaviors—including exercise, sleep, and stress—would give a clearer view of health and allow the app to deliver more personalized recommendations. To integrate these additional wellness insights into its app, Signos developers used Health Connect, an Android API that unifies health and fitness data from multiple devices and apps into one platform.

 

Putting the member first

Signos integrated Health Connect so its members’ health and fitness data from apps like Fitbit, Samsung Health, and Google Fit can be automatically synced to the Signos app. Instead of requiring members to manually input this data from multiple sources, they can use Health Connect and enable Signos to sync with the other integrated apps they use to support their well-being. Not only does this save members time, it also ensures consistent and accurate data.

With Health Connect, it’s easier for Signos to identify patterns in a member's health and offer more insightful recommendations based on their glucose patterns. It also provides Signos members with a better understanding of how their daily choices affect their glucose, metabolic health, and weight by bringing their health data together in Signos, where they can easily view it and make comprehensive connections.

Signos understands data privacy is important, and with Health Connect, Signos members can securely manage their health information on Android devices. When a member first opens Health Connect, they're guided through the process of selecting which health metrics and apps they want to provide access to, giving them complete control of what's made available to Signos.

 

One implementation for many data sources

Before implementing Health Connect, Signos developers struggled to connect relevant data from multiple sources because many APIs weren't available or too many integrations needed to be created and maintained. This meant the Signos team had to write individual integrations to support multiple API surfaces for every app they wanted to sync data from. Now, they only need to write one, saving them a tremendous amount of development time and effort.

With a single API connection through Health Connect, Signos was able to unify health and wellness data from the apps most used by members. “Now that data from workouts, sleep, weight logs, and heart rate automatically sync from other apps, members can see how all of this data impacts their glucose throughout the day,” said Emma Allison, vice president of product at Signos.

Additionally, implementing Health Connect is simple. Using specialized constructors, Signos developers were able to take Health Connect records and convert them into the internal models used for Signos’ health data. This allowed the Signos app to process Health Connect data the same way it processes its own, so the experience is completely seamless to members. Sleep logged from their wearables that’s synced through Health Connect looks exactly the same to them as sleep logged straight into Signos.

 

“One aspect I was pleasantly surprised by was the user onboarding UX,” said Signos developer Jake Smith. “A simple, drop-in piece of code brings them straight to the Play Store to install Health Connect and then right back to the app so they can set up the permissions and start reaping the benefits.”

 

More connections, more opportunities

Currently, Health Connect’s first integration with Signos syncs personal wellness data like exercise, heart rate, sleep, and hydration. In the future, Signos plans to build out more robust integrations and in-app experiences with each data set, including women’s health, nutrition, and even mindfulness.

Signos is excited about what the future of Health Connect will bring. Health Connect helps standardize different data types and allows Android apps to freely connect to the API, so Signos won’t have to create any further integrations as other apps adopt Health Connect. This means that as the Health Connect ecosystem grows, so will Signos’ ability to help its members.

 

Get started with Health Connect

Health Connect lets developers and users securely connect with multiple Android apps and devices. Watch the DevByte introduction video to learn how you can get started with Health Connect.

 

 

https://android-developers.googleblog.com/2023/01/signos-streamlines-integrations-with-health-fitness-apps-through-health-connect-api.html

Leading Health and Fitness Apps Roll Out Health Connect Integrations

Earlier this year, we introduced Health Connect as a way for app developers like you to have early access to a platform that securely shares health and fitness data across Android devices, with user consent. We collaborated with Samsung to build this platform which simplifies the connectivity between your apps while providing centralized privacy controls for users. We are now making the Health Connect (Beta) app available for download in Google Play to give users a central place to manage their privacy settings with granular controls to see which apps have access to data at any given time.

By enabling health and fitness apps to talk to each other, each app is able to provide a user with better, more holistic health insights.

In the past, developers had to establish multiple API connections to share data between different apps and each integration was costly to build and maintain. This limited developers’ data sharing capabilities and made it hard for users to unlock this data so that it could be utilized in different apps.

Now, with Health Connect, building an integration with a new app is as simple as reading in new data from Health Connect, rather than building a whole new integration.

For example, Android users will now be able to sync and get credit for their Peloton workouts in apps like Oura, MyFitnessPal, WeightWatchers and Lifesum. Now, through a single integration with Health Connect, Peloton Members will have the option to share their workout stats across the ecosystem of apps they use to support their overall wellness.

Standardized data schema ensures data consistency between apps

"With Health Connect APIs, our engineers were able to easily adapt their existing architecture in order to read and write user health data such as nutrition, hydration, exercise, and steps. With this integration, we're now able to consume data from any 3rd party application that also writes to Health Connect, expanding our users' choices while allowing them more flexibility to grant granular permissions about which data they want to share"
– Jason Peterson, Chief Technology Officer of MyFitnessPal

Centralize privacy controls for users, with less code

Previously, users had to navigate to multiple apps to manage data permissions. And, developers had to build out permissions management UIs themselves.

With Health Connect, users can easily manage permissions in a single place, with granular controls to see which apps are accessing data at any given time.

For developers, Health Connect provides the permissions management hub and granular permissions UIs out of the box, so you can set this up quickly.

granular permissions screen that shows the different data types

For example, Signos was able to quickly set up permissions checks with Health Connect. “One aspect I was pleasantly surprised by was the user onboarding UX,” said Signos developer Jake Smith. “A simple, drop-in piece of code sets up the permissions so users can start reaping the benefits.”

We’re just getting started

Join the many developers who have already integrated with Health Connect and don’t miss out on the opportunity to develop richer insights for your users. Check out our documentation, helpful video tutorials, and code samples – and start building today!

From helping you log your meals with MyFitnessPal to getting a holistic view of your health with Withings, apps and devices are a source for many kinds of useful health and fitness data. As Android developers, connecting and sharing this data between apps can help you provide more meaningful experiences and insights for your users. However, much of this information is spread across multiple experiences and different devices, making it difficult to bring together. Moreover, there are no centralized privacy controls for Android users.

Introducing Health Connect

This is why we’ve created Health Connect, a platform and API for Android app developers. With user permission, developers can use a single set of APIs to securely access and share health and fitness data across Android devices.

We're building this new unified platform in collaboration with Samsung to simplify connectivity between apps. We appreciate Samsung’s collaboration as we roll out Health Connect to foster richer app experiences while also providing centralized privacy controls for users.

We've been working with developers including MyFitnessPal, Leap Fitness and Withings as part of an early access program. In addition, Samsung Health, Google Fit and Fitbit are adopting Health Connect. Starting today, all developers can get access to Health Connect's common set of APIs for Android via Android Jetpack.

Health Connect fits in with Google’s wider efforts to help billions of people be healthier, using our platforms and technology to connect and bring more meaning to health information.

How does Health Connect work?

How Health Connect Works

Health Connect supports many common health and fitness data types and categories, including: activity, sleep, nutrition, body measurements and vitals like heart rate and blood pressure.

With user permission, developers can securely read from and write data to Health Connect, using standardized schema and API behavior. Users will have full control over their privacy settings, with granular controls to see which apps are requesting access to data at any given time. The data in Health Connect is all on-device and encrypted. Users will have the ability to shut off access or delete data they don’t want on their device, and the option to prioritize one data source over another when using multiple apps.

Getting started

It’s easy to get started with Health Connect. Health Connect’s single set of APIs makes it simple to manage permissions and read and write data. Here’s an example of how you can request permissions and then write some data.

First, build a set of the permissions you plan to request read or write access to. In this example we are reading and writing steps and heart rate.

private val permissions =
  setOf(
    Permission.createReadPermission(Steps::class),
    Permission.createWritePermission(Steps::class),
    Permission.createReadPermission(HeartRate::class),
    Permission.createWritePermission(HeartRate::class),
  )

// then, create a permissions request for this set of permissions

Then, launch the permissions request, which will bring the user to the Health Connect permissions UI to grant permissions.

Once the user grants permission, you are ready to read and write data. Here’s an example of how to write steps data over a period of time. Include the total number of steps, start and end time, and timezone information, and then insert the data into Health Connect.

private suspend fun writeSomeData(client: HealthConnectClient) {
    val records = mutableListOf<Record>()

    records.add(
      Steps(
        count = 888,
        startTime = START_TIME,
        endTime = END_TIME,
        startZoneOffset = null,
        endZoneOffset = null,
      )
    )
    // add additional records as needed
}

Learn more

Health Connect is now available to developers:

• Check out the Documentation
• Download the SDK from Android Jetpack
• Review the revised privacy & security policy
• Find code samples on our Github page
• Sign up for the open beta via Google Play

Watch the technical session below:

https://android-developers.googleblog.com/search/label/Health%20Connect%20API

### 이슈

java.lang.SecurityException: Need android.permission.BLUETOOTH_SCAN permission for AttributionSource 
{ uid = 10965, packageName =  ### , attributionTag = null, token = android.os.BinderProxy@b85f7e3, next = null }: 
GattService registerScanner

### 해결방안 

> 안드로이드 12 적용하면서 Android 12에서는 BLUETOOTH_SCAN, BLUETOOTH_ADVERTISE, BLUETOOTH_CONNECT 권한을 도입합니다. 이를 통해 앱이 위치 정보 액세스 권한을 요청하지 않고도 근처 기기를 검색할 수 있습니다. 이러한 권한을 선언하려면 앱이 Android 12를 타겟팅해야 한다. 

1. manifest 적용 

<manifest>
    <!-- Request legacy Bluetooth permissions on older devices. -->
    <uses-permission android:name="android.permission.BLUETOOTH"
                     android:maxSdkVersion="30" />
    <uses-permission android:name="android.permission.BLUETOOTH_ADMIN"
                     android:maxSdkVersion="30" />

    <!-- Needed only if your app looks for Bluetooth devices.
         You must add an attribute to this permission, or declare the
         ACCESS_FINE_LOCATION permission, depending on the results when you
         check location usage in your app. -->
    <uses-permission android:name="android.permission.BLUETOOTH_SCAN" />

    <!-- Needed only if your app makes the device discoverable to Bluetooth
         devices. -->
    <uses-permission android:name="android.permission.BLUETOOTH_ADVERTISE" />

    <!-- Needed only if your app communicates with already-paired Bluetooth
         devices. -->
    <uses-permission android:name="android.permission.BLUETOOTH_CONNECT" />
    ...
</manifest>

2. 블루투스 사용 권한 요청 시 requestPermission 요청 

if (PermissionType.BLUETOOTH == type ) {
            permissions.add(Manifest.permission.ACCESS_COARSE_LOCATION);
            permissions.add(Manifest.permission.ACCESS_FINE_LOCATION);
            permissions.add(Manifest.permission.BLUETOOTH);
            permissions.add(Manifest.permission.BLUETOOTH_ADMIN);
            permissions.add(Manifest.permission.BLUETOOTH_SCAN);
            permissions.add(Manifest.permission.BLUETOOTH_ADVERTISE);
            permissions.add(Manifest.permission.BLUETOOTH_CONNECT);
    }

https://developer.android.com/about/versions/12/features/bluetooth-permissions?hl=ko 

Apple Worldwide Developer Relations Intermediate Certificate updates

Starting January 28, 2021, the digital certificates you use to sign your software for installation on Apple devices, submit apps to the App Store, and connect to certain Apple services will be issued from the new intermediate Apple Worldwide Developer Relations certificate that expires on February 20, 2030. Learn how to prepare for the new intermediate certificate.

Using the new certificate with Xcode

If you’re running Xcode 11.4.1 or later, you’ll receive the updated certificate automatically when you sign an app after January 28, 2021. If you’re running an earlier release of Xcode and need to generate new certificates, download and install the new intermediate certificate and utilize the command line to sign your app. You can also archive your build with your existing Xcode version and sign it for distribution with Xcode 11.4.1 or later.

Why is the Apple Worldwide Developer Relations Certification Authority being updated now if the current version doesn’t expire until 2023?

Certificates cannot be issued with a validity period that extends past the intermediate certificate’s expiration date. Updating the intermediate certificate allows developers to obtain certificates before expiration that last for the expected duration, and provides ample time to prepare for the expiration of the existing intermediate certificate.

Do I need to regenerate any of my certificates?

No. Your existing certificates will continue to function until expiration or revocation, whichever comes first.

Will customers be affected by the certificate renewal?

No. Customers who have installed apps from the App Store or Safari Extensions will not be affected by the certificate renewal.

Will my apps in development continue working?

Yes. The development versions of your apps will continue to run until the provisioning profile used to compile them expires or you revoke your signing certificate.

Will my in-house enterprise apps continue working?

Yes. All in-house enterprise apps for iOS, iPadOS, tvOS, or watchOS that you’ve deployed will continue to run as expected until the provisioning profile used to compile them expires or you revoke your signing certificate. The iOS Distribution Certificate for the Apple Developer Enterprise Program was updated on September 1, 2020. iOS Distribution Certificates generated as part of the Apple Developer Enterprise Program between February 7 and September 1, 2020, will expire on February 7, 2023. Rotate the certificate before expiration to ensure your apps are installed and signed with an active certificate.

Should I keep both intermediate certificates installed?

Yes. The intermediate certificate that expires on February 7, 2023, will continue to issue select Apple services certificates, including Apple Push Notification service (APNs) SSL certificates and Apple Wallet pass signing certificates, so you should keep both versions installed on your development systems and servers. See the complete list and timeline of certificate changes below.

In what cases should I continue using the certificate that expires in 2023?

Continue using the existing Apple Worldwide Developer Relations Intermediate Certificate (expiring in 2023) if you use any of the certificates signed with it that are listed below. These services will be updated with a new intermediate certificate (expiring in 2030) by the the end of 2021. Keep both versions installed on your development systems and servers until later this year.

• Apple Push Notification service SSL (Sandbox)
• Apple Push Notification service SSL (Sandbox and Production)
• macOS Apple Push Notification service SSL (Production)
• Website Push ID
• WatchKit Services
• VoIP Services
• Pass Type ID
• Pass Type ID with NFC support
• App Store Receipt Signing

Is Developer ID signed software affected?

No. Developer ID signing certificates are associated with a different intermediate certificate and aren’t affected by this renewal.

Certificate update timeline

These certificates will be issued with the new intermediate certificate (expiring in 2030).

September 1, 2020

iOS Distribution for Enterprise Developer Program memberships

January 28, 2021

• Apple Development
• Apple Distribution
• iOS App Development
• iOS Distribution (App Store and Ad Hoc)
• Mac Development
• Mac App Distribution
• Mac Installer Distribution
• MDM CSR
• Apple Pay Merchant Identity

Updated by end of 2021

• Apple Push Notification service SSL (Sandbox)
• Apple Push Notification service SSL (Sandbox and Production)
• macOS Apple Push Notification service SSL (Production)
• Website Push ID
• WatchKit Services
• VoIP Services
• Pass Type ID
• Pass Type ID with NFC support
• App Store Receipt Signing

No changes

These certificates are not associated with the Apple Worldwide Developer Intermediate Certificate and are not affected by this change.

• Developer ID Application
• Developer ID Application with KEXT
• Developer ID Installer
• Apple Pay Payment Processing

보통 "아니요"를 눌러서 바로 TestFlight에 등록하지만, code 상에서 미리 넣어 둘 수 있다.

Info.plist

<key>ITSAppUsesNonExemptEncryption</key><false/>

help.apple.com/xcode/mac/current/#/dev0dc15d044

1. fullScreen
2. pageSheet
3. formSheet
4. currentContext
5. custom
6. overFullScreen
7. overCurrentContext
8. popover
9. none

https://developer.apple.com/documentation/uikit/uimodalpresentationstyle

수익 창출 및 광고

2020년 4월 16일 이후에 게시되는 신규 앱 또는 업데이트에는 모두 최신 버전의 개발자 프로그램 정책이 바로 적용됩니다. 2020년 4월 16일 자로 Google Play에 게재된 앱은 이 날짜로부터 60일 이내에 정책을 준수해야 합니다.

정기 결제

개발자는 앱 내에서 제공하는 정기 결제 서비스나 콘텐츠에 관해 사용자를 오도해서는 안 됩니다. 모든 인앱 프로모션 또는 스플래시 화면에서 명확한 정보를 전달하는 것이 중요합니다.

앱 내에서는 혜택에 관해 투명하게 설명해야 합니다. 여기에는 정기 결제 가격, 결제 주기 빈도, 앱을 사용하려면 정기 결제가 필요한지 등 혜택의 조건을 명확하게 설명하는 것이 포함됩니다. 사용자가 추가적인 조치를 취하지 않아도 이러한 정보를 검토할 수 있어야 합니다.

다음은 자주 발생하는 위반 사례입니다.

• 월별 정기 결제에서 사용자에게 정기 결제가 자동 갱신되어 매달 요금이 청구된다는 사실을 알리지 않습니다.
• 연간 정기 결제에서 월간 정기 결제 가격을 가장 두드러지게 표시합니다.
• 정기 결제 가격 및 약관이 완전히 현지화되어 있지 않습니다.
• 인앱 프로모션에서 정기 결제 없이도 콘텐츠에 액세스할 수 있다는 점(가능한 경우)을 명확하게 설명하지 않습니다.
• SKU 이름이 정기 결제의 성격을 정확하게 전달하지 않습니다. 예를 들어 자동으로 반복 요금이 청구되는 정기 결제의 이름이 '무료 체험판'인 경우가 있습니다.

① 닫기 버튼이 명확하게 보이지 않으며 사용자가 정기 결제 혜택을 수락하지 않아도 기능에 액세스할 수 있다는 사실을 이해할 수 없습니다.

② 혜택에 월별 가격만 표시되어 있어 사용자가 정기 결제를 신청할 때 6개월 가격이 청구된다는 사실을 이해할 수 없습니다.

③ 혜택에 신규 할인 가격만 표시되어 있어 신규 할인 기간이 종료된 후 어떤 가격이 자동으로 청구되는지 사용자가 이해할 수 없습니다.

④ 혜택은 사용자가 혜택의 전체 내용을 이해할 수 있도록 이용약관과 동일한 언어로 현지화되어 있어야 합니다.

무료 체험판 및 신규 할인 혜택

사용자가 정기 결제에 등록하기 전: 기간, 가격, 사용 가능한 콘텐츠 또는 서비스 설명 등 제안의 조건을 명확하고 정확하게 설명해야 합니다. 무료 체험판이 유료 정기 결제로 전환되는 시점과 방식, 유료 정기 결제의 가격, 유료 정기 결제로 전환하고 싶지 않은 경우 정기 결제를 취소할 수 있음을 사용자에게 알려야 합니다.

다음은 자주 발생하는 위반 사례입니다.

• 무료 체험판 기간 또는 신규 할인 가격의 적용 기간을 명확하게 설명하지 않습니다.
• 제안 기간이 끝나면 유료 정기 결제로 자동 전환된다는 사실을 사용자에게 명확하게 설명하지 않습니다.
• 체험판 없이도 콘텐츠를 사용할 수 있다는 점(가능한 경우)을 명확하게 설명하지 않습니다.
• 현지화가 완료되지 않은 가격 및 약관을 제공합니다.

① 닫기 버튼이 명확하게 보이지 않아서 사용자가 무료 체험판에 가입하지 않아도 기능에 액세스할 수 있다는 사실을 알 수 없습니다.

② 제안에서 무료 체험판임을 강조해서 사용자는 체험 기간이 종료되면 자동으로 요금이 청구된다는 사실을 알 수 없습니다.

③ 제안에 체험 기간이 명시되어 있지 않아서 사용자가 정기 결제 콘텐츠에 언제까지 무료로 액세스할 수 있는지 알 수 없습니다.

④ 제안은 사용자가 제안의 전체 내용을 이해할 수 있도록 이용약관과 동일한 언어로 현지화되어 있어야 합니다.

정기 결제 관리 및 취소

개발자는 사용자가 정기 결제를 관리 또는 취소하는 방법이 앱에 명확하게 설명되어 있는지 확인해야 합니다.

Google Play 정책에 따르면 사용자가 Google Play의 앱에서 신청한 정기 결제를 취소할 경우 현재 결제 기간에 해당하는 요금을 환불받을 수 없지만, 취소일과 관계없이 현재 결제 기간에서 남은 기간 동안 정기 결제 콘텐츠를 계속해서 이용할 수 있습니다. 사용자의 정기 결제 취소는 현재 결제 기간이 지난 이후 적용됩니다.

개발자는 콘텐츠 또는 액세스 권한 제공자로서 사용자에게 더 유리한 환불 정책을 직접 적용할 수 있습니다. 사용자에게 정기 결제, 취소, 환불 정책의 변경사항을 알리고 정책이 관련 법규를 준수하도록 할 의무는 개발자에게 있습니다.

play.google.com/about/monetization-ads/subscriptions/

DisplayMetrics DisplayMetrics 구조체에서 디스플레이에 대한 정보를 얻을 수 있다. 

Android는 직접 픽셀 매핑을 사용하지 않지만 소수의 Density Independent Pixel 값을 사용하여 실제 화면 크기에 맞게 조정한다. 

| 방법1. 밀도 상수로 구분

DisplayMetrics metrics = getResources().getDisplayMetrics();
int density = metrics.densityDpi
// DENSITY_xxx 상수 (120, 160, 213, 240, 320, 480 또는 640 dpi) 중 하나
 

** 실제lcd 픽셀 밀도가 필요한 경우

수평 및 수직 밀도 각각에 대해 metrics.xdpi 및 metrics.ydpi 속성에서 가져올 수 있다. 

DisplayMetrics dm = new DisplayMetrics();
getWindowManager().getDefaultDisplay().getMetrics(dm);

// will either be DENSITY_LOW, DENSITY_MEDIUM or DENSITY_HIGH
int dpiClassification = dm.densityDpi;

// these will return the actual dpi horizontally and vertically
float xDpi = dm.xdpi;
float yDpi = dm.ydpi;

| 방법2. 상수값으로 구분

//방법 2 상수
getResources().getDisplayMetrics().density;

/*
0.75 - ldpi
1.0 - mdpi
1.5 - hdpi
2.0 - xhdpi
3.0 - xxhdpi
4.0 - xxxhdpi
*/

// 4이전의 API 수준을 대상으로 지정하는 경우 : metrics.density = 참조밀도(160dpi)의 소수점 배율 인수 
int densityDpi = (int)(metrics.density * 160f);

| Sample Code

int densityDpi = getResources().getDisplayMetrics().densityDpi;

switch (densityDpi)
{
    case DisplayMetrics.DENSITY_LOW:
        // LDPI : density == 0.75f
        break;

    case DisplayMetrics.DENSITY_MEDIUM:
        // MDPI : density >= 1.0f && density < 1.5f 
        break;

    case DisplayMetrics.DENSITY_TV:
    case DisplayMetrics.DENSITY_HIGH:
        // HDPI : density == 1.5f
        break;

    case DisplayMetrics.DENSITY_XHIGH:
    case DisplayMetrics.DENSITY_280:
        // XHDPI : density > 1.5f && density <= 2.0f
        break;

    case DisplayMetrics.DENSITY_XXHIGH:
    case DisplayMetrics.DENSITY_360:
    case DisplayMetrics.DENSITY_400:
    case DisplayMetrics.DENSITY_420:
        // XXHDPI : density > 2.0f && density <= 3.0f
        break;

    case DisplayMetrics.DENSITY_XXXHIGH:
    case DisplayMetrics.DENSITY_560:
        // XXXHDPI : density > 4.0f
        break;
}

Summary 

Fields

Public constructors

Public methods

Predefined sounds

There are some predefined system sounds, for the system sound ID in the range 1000 to 2000 (decimal), as shown below (from 2.0 to 5.0 beta). The system sounds are all stored in /System/Library/Audio/UISounds/.

http://iphonedevwiki.net/index.php/AudioServices

http://onj3.andrelouis.com/phonetones/unzipped/Apple-iOS10/System/Library/Audio/UISounds/New/