Java HarmonyOS API for Android developers - cheatsheet

HarmonyOSAndroidCheatSheet.MD

Basic Applications Elements

Android	HarmonyOS	Notes / Usage
Application	AbilityPackage
Activity	Ability (Page Ability)	An ability is an abstraction of a functionality that an application can provide. Abilities are classified into Feature Abilities (FAs) and Particle Abilities (PAs). Ability class can be used similar to Activity, then it is FA and uses Page template. Docs: https://developer.harmonyos.com/en/docs/documentation/doc-guides/ability-page-concept-0000000000033573
Fragment	AbilitySlice	AbilitySlice represents a single screen and its control logic.
Service	Ability (Service Ability)	Ability class can be used similar to Service. Docs: https://developer.harmonyos.com/en/docs/documentation/doc-guides/ability-service-concept-0000000000044457
	Ability (Data Abilty)	A Data ability helps applications manage access to data stored by themselves and other applications, and provides methods for sharing data with other applications. Data abilities can be used for data sharing between applications on the same device or across different devices. Docs: https://developer.harmonyos.com/en/docs/documentation/doc-guides/ability-data-concept-0000000000043058
Intent	Intent	Docs: https://developer.harmonyos.com/en/docs/documentation/doc-guides/ability-intent-0000000000038799
Context	Context

UI Basics

Overview docs: https://developer.harmonyos.com/en/docs/documentation/doc-guides/ui-java-overview-0000000000500404

Android	HarmonyOS
View	Component
ViewGroup	ComponentContainer
ViewGroup.LayoutParams	ComponentContainer.LayoutConfig

Views / Components

Android	HarmonyOS	Notes / Usage
TextView	TextView	https://developer.harmonyos.com/en/docs/documentation/doc-guides/ui-java-component-text-0000001050729534
Button	Button	https://developer.harmonyos.com/en/docs/documentation/doc-guides/ui-java-component-button-0000001051009585
EditText	TextField	https://developer.harmonyos.com/en/docs/documentation/doc-guides/ui-java-component-textfield-0000001061125582
ImageView	Image	https://developer.harmonyos.com/en/docs/documentation/doc-guides/ui-java-component-image-0000001058976860
TabLayout / TabItem	TabList / Tab	https://developer.harmonyos.com/en/docs/documentation/doc-guides/ui-java-component-tablist-tab-0000001062229749
DatePickerDialog	DatePicker (Component)	https://developer.harmonyos.com/en/docs/documentation/doc-guides/ui-java-component-datepicker-0000001060237839
TimePickerDialog	TimePicker (Component)	https://developer.harmonyos.com/en/docs/documentation/doc-guides/ui-java-component-timepicker-0000001060648140
Switch	Switch	https://developer.harmonyos.com/en/docs/documentation/doc-guides/ui-java-component-switch-0000001060806006
RadioButton	RadioButton	https://developer.harmonyos.com/en/docs/documentation/doc-guides/ui-java-component-radiobutton-0000001060647792
RadioGroup	RadioContainer	https://developer.harmonyos.com/en/docs/documentation/doc-guides/ui-java-component-radiocontainer-0000001063470429
CheckBox	CheckBox	https://developer.harmonyos.com/en/docs/documentation/doc-guides/ui-java-component-checkbox-0000001060487804
ProgressBar / LinearProgressIndicator	ProgressBar	https://developer.harmonyos.com/en/docs/documentation/doc-guides/ui-java-component-progressbar-0000001060379891
CircularProgressIndicator (material)	RoundProgressBar	https://developer.harmonyos.com/en/docs/documentation/doc-guides/ui-java-component-roundprogressbar-0000001062558057
ScrollView	ScrollView	https://developer.harmonyos.com/en/docs/documentation/doc-guides/ui-java-component-scrollview-0000001060965602
ListView / RecyclerView	ListContiner (works similar to ListView)	https://developer.harmonyos.com/en/docs/documentation/doc-guides/ui-java-component-listcontainer-0000001060007847
ViewPager	PageSlider (with PageSliderIndicator)	https://developer.harmonyos.com/en/docs/documentation/doc-guides/ui-java-component-pageslider-0000001091933258 https://developer.harmonyos.com/en/docs/documentation/doc-guides/ui-java-component-pagesliderindicator-0000001091773342
WebView	WebView	https://developer.harmonyos.com/en/docs/documentation/doc-guides/ui-java-component-webview-0000001092715158

Layouts / ViewGroups

Android	HarmonyOS	Notes / Usage
LinearLayout	DirectionaLayout	https://developer.harmonyos.com/en/docs/documentation/doc-guides/ui-java-layout-directionallayout-0000001050769565
RelativeLayout / ConstraintLayout	DependentLayout (works similar to RelativeLayout)	https://developer.harmonyos.com/en/docs/documentation/doc-guides/ui-java-layout-dependentlayout-0000001050729536
FrameLayout	StackLayout	https://developer.harmonyos.com/en/docs/documentation/doc-guides/ui-java-layout-stacklayout-0000001060357540
GridLayout	TableLayout	https://developer.harmonyos.com/en/docs/documentation/doc-guides/ui-java-layout-tablelayout-0000001060379893
AbsoluteLayout	PositionLayout	https://developer.harmonyos.com/en/docs/documentation/doc-guides/ui-java-layout-positionlayout-0000001062250815
	AdaptiveBoxLayout	https://developer.harmonyos.com/en/docs/documentation/doc-guides/ui-java-layout-adaptiveboxlayout-0000001104341118

Dialogs, popups, toasts

Android	HarmonyOS	Notes / Usage
Toast	ToastDialog	https://developer.harmonyos.com/en/docs/documentation/doc-guides/ui-java-component-toastdialog-0000001060125963
PopupWindow	PopupDialog	PopupDialog can be attached to a Component. Docs: https://developer.harmonyos.com/en/docs/documentation/doc-guides/ui-java-component-popupdialog-0000001150714408
AlertDialog	CommonDialog	https://developer.harmonyos.com/en/docs/documentation/doc-guides/ui-java-component-commondialog-0000001150874228

Custom Views / Components

Docs: https://developer.harmonyos.com/en/docs/documentation/doc-guides/ui-java-custom-component-layout-overview-0000001139508543

Android	HarmonyOS	Notes / Usage
onMeasure	onEstimateSize
onLayout	onArrange
AttributeSet	AttrSet
onDraw	onDraw
LayoutInflater	LayoutScatter	LayoutScatter.getInstance(context).parse(ResourceTable.Layout_title_bar, component, true);

Lifecycle

Application / AbilityPackage

Android	HarmonyOS
onCreate	onInitialize
onTerminate	onEnd
onConfigurationChanged	onConfigurationUpdated
onTrimMemory / onLowMemory	onMemoryLevel
registerActivityLifecycleCallbacks / registerComponentCallbacks	registerCallbacks
unregisterActivityLifecycleCallbacks / registerComponentCallbacks	unregisterCallbacks

Activity / Ability

Docs: https://developer.harmonyos.com/en/docs/documentation/doc-guides/ability-page-lifecycle-0000000000029840

Android	HarmonyOS
onCreate	onStart
onStart	----
onResume	onActive
onPause	onInactive
onStop	onBackground
onRestart	onForeground
onDestroy	onStop

Service / Ability

Docs: https://developer.harmonyos.com/en/docs/documentation/doc-guides/ability-service-creating-0000000000044464

Android	HarmonyOS
onCreate	onStart
onStartCommand	onCommand
onBind	onConnect
onDestroy	onStop

Fragment / AbilitySlice

An ability slice's lifecycle is bound to the Page ability that hosts it. An ability slice has the same lifecycle states and lifecycle callbacks as its host Page ability. Once the lifecycle state of a Page ability changes, its ability slices undergo the same change. An ability slice can also have its own lifecycle state changes, which occur during the switching between the ability slices within the Page ability. Such a switching does not affect the host ability's lifecycle.

Docs: https://developer.harmonyos.com/en/docs/documentation/doc-guides/ability-page-lifecycle-0000000000029840

XML Layouts

Docs: https://developer.harmonyos.com/en/docs/documentation/doc-guides/ui-java-component-layout-xml-0000000000500395

Android	HarmonyOS
android:id="@+id/text"	ohos:id="$+id:text"
android:layout_width="20dp"	ohos:width="20vp"
android:layout_height="20dp"	ohos:height="20vp"
match_parent	match_parent
wrap_content	match_content

AndroidManifest.xml / config.json

In HarmonyOS there is a config.json file instead of AndroidManifest.xml. Docs: https://developer.harmonyos.com/en/docs/documentation/doc-guides/basic-config-file-overview-0000000000011951

Resources

All the application resource files, such as strings, images, and audio files, are stored in the resources directory, allowing you to easily access, use, and maintain them. The resources directory consists of two types of sub-directories: the base sub-directory and qualifiers sub-directories, and the rawfile sub-directory.

Example:

resources
|---base  // Default directory
|   |---element
|   |   |---string.json
|   |---media
|   |   |---icon.png
|---en_GB-vertical-car-mdpi // Example of a qualifiers sub-directory, which needs to be created on your own
|   |---element
|   |   |---string.json
|   |---media
|   |   |---icon.png
|---rawfile  // Default directory

Docs: https://developer.harmonyos.com/en/docs/documentation/doc-guides/basic-resource-file-categories-0000001052066099#EN-US_TOPIC_0000001062847941__table1324121514614

Referencing Resource Files

Resource files are referenced in a Java file in the following format: ResourceTable.type_name. Specifically, a system resource is referenced using ohos.global.systemres.ResourceTable.type_name.

Resource files are referenced in an XML file in the following format: $type:name. Specifically, a system resource is referenced using $ohos:type:name.

Docs: https://developer.harmonyos.com/en/docs/documentation/doc-guides/basic-resource-file-example-0000001051733014

Examples:

Android	HarmonyOS
findViewById(R.id.textView)	findComponentById(ResourceTable.Id_textView)
setContentView(R.layout.activity_main)	setUIContent(ResourceTable.Layout_ability_main)
<ImageView android:src="@drawable/plant"/>	<Image ohos:image_src="$media:plant" />
getString(R.string.hello)	getResourceManager().getElement(ResourceTable.String_hello).getString()

Permissiosns

Docs: https://developer.harmonyos.com/en/docs/documentation/doc-guides/security-permissions-overview-0000000000029883

• permissions are definied in config.json
• sensitive permissions must be dynamically requested with users' acknowledgement (https://developer.harmonyos.com/en/docs/documentation/doc-guides/security-permissions-guidelines-0000000000029886#section7431121314439)

Android	HarmonyOS
checkSelfPermission(..)	verifySelfPermission(..)
requestPermissions(..)	requestPermissionsFromUser(..)
onRequestPermissionsResult(..)	onRequestPermissionsFromUserResult(..)
PackageManager.PERMISSION_GRANTED	IBundleManager.PERMISSION_GRANTED

Contributing

If you think there could be more items in this cheatsheat please open an issue or a PR. Repository: https://github.com/burnoo/HarmonyOSAndroidCheatsheet/