UIAbility是系统调度的最小单元。在设备内的功能模块之间跳转时,会涉及到启动特定的UIAbility,包括应用内的其他UIAbility、或者其他应用的UIAbility(例如启动三方支付UIAbility)。
一、启动应用内的UIAbility
当一个应用内包含多个UIAbility时,存在应用内启动UIAbility的场景。例如在支付应用中从入口UIAbility启动收付款UIAbility。
假设应用中有两个UIAbility:EntryAbility和FuncAbility(可以在同一个Module中,也可以在不同的Module中),需要从EntryAbility的页面中启动FuncAbility。
1.在EntryAbility中,通过调用startAbility()方法启动UIAbility,want为UIAbility实例启动的入口参数,其中bundleName为待启动应用的Bundle名称,abilityName为待启动的Ability名称,moduleName在待启动的UIAbility属于不同的Module时添加,parameters为自定义信息参数。示例中的context的获取方式请参见获取UIAbility的上下文信息。
bash
import { common, Want } from '@kit.AbilityKit';
import { hilog } from '@kit.PerformanceAnalysisKit';
import { BusinessError } from '@kit.BasicServicesKit';
const TAG: string = '[Page_UIAbilityComponentsInteractive]';
const DOMAIN_NUMBER: number = 0xFF00;
@Entry
@Component
struct Page_UIAbilityComponentsInteractive {
private context = getContext(this) as common.UIAbilityContext;
build() {
Column() {
//...
List({ initialIndex: 0 }) {
ListItem() {
Row() {
Text('打开 FuncAbilityA')
.fontSize(20)
.fontWeight(FontWeight.Medium)
.margin({ top: 20 })
}
.onClick(() => {
// context为Ability对象的成员,在非Ability对象内部调用需要
// 将Context对象传递过去
let wantInfo: Want = {
deviceId: '', // deviceId为空表示本设备
bundleName: 'com.samples.stagemodelabilitydevelop',
moduleName: 'entry', // moduleName非必选
abilityName: 'FuncAbilityA',
parameters: {
// 自定义信息
info: '来自EntryAbility Page_UIAbilityComponentsInteractive页面'
},
};
// context为调用方UIAbility的UIAbilityContext
this.context.startAbility(wantInfo).then(() => {
hilog.info(DOMAIN_NUMBER, TAG, 'startAbility success.');
}).catch((error: BusinessError) => {
hilog.error(DOMAIN_NUMBER, TAG, 'startAbility failed.');
});
})
}
//...
}
//...
}
//...
}
}
2.在FuncAbility的onCreate()或者onNewWant()生命周期回调文件中接收EntryAbility传递过来的参数。
bash
import { AbilityConstant, UIAbility, Want } from '@kit.AbilityKit';
import { hilog } from '@kit.PerformanceAnalysisKit';
import { window } from '@kit.ArkUI';
const TAG: string = '[FuncAbilityA]';
const DOMAIN_NUMBER: number = 0x0000;
export default class FuncAbilityA extends UIAbility {
onCreate(want: Want, launchParam: AbilityConstant.LaunchParam): void {
// 接收调用方UIAbility传过来的参数
let funcAbilityWant = want;
let info = funcAbilityWant?.parameters?.info;
hilog.info(DOMAIN_NUMBER, TAG, '%{public}s', `Ability onCreate 接收到的参数 info = ${info}`);
}
onDestroy(): void {
hilog.info(DOMAIN_NUMBER, TAG, '%{public}s', 'Ability onDestroy');
}
onWindowStageCreate(windowStage: window.WindowStage): void {
// Main window is created, set main page for this ability
hilog.info(DOMAIN_NUMBER, TAG, '%{public}s', 'Ability onWindowStageCreate');
windowStage.loadContent('pages/Index', (err) => {
if (err.code) {
hilog.error(DOMAIN_NUMBER, TAG, 'Failed to load the content. Cause: %{public}s', JSON.stringify(err) ?? '');
return;
}
hilog.info(DOMAIN_NUMBER, TAG, 'Succeeded in loading the content.');
});
}
onWindowStageDestroy(): void {
// Main window is destroyed, release UI related resources
hilog.info(DOMAIN_NUMBER, TAG, '%{public}s', 'Ability onWindowStageDestroy');
}
onForeground(): void {
// Ability has brought to foreground
hilog.info(DOMAIN_NUMBER, TAG, '%{public}s', 'Ability onForeground');
}
onBackground(): void {
// Ability has back to background
hilog.info(DOMAIN_NUMBER, TAG, '%{public}s', 'Ability onBackground');
}
}
效果图
说明在被拉起的FuncAbility中,可以通过获取传递过来的want参数的parameters来获取拉起方UIAbility的PID、Bundle Name等信息。
3.在FuncAbility业务完成之后,如需要停止当前UIAbility实例,在FuncAbility中通过调用terminateSelf()方法实现。
bash
// UIAbility组件间交互(设备内)https://developer.huawei.com/consumer/cn/training/course/slightMooc/C101717497122909477
import { common, Want } from '@kit.AbilityKit';
import { hilog } from '@kit.PerformanceAnalysisKit';
import { BusinessError } from '@kit.BasicServicesKit';
const TAG: string = '[Page_FromStageModel]';
const DOMAIN_NUMBER: number = 0xFF00;
@Entry
@Component
struct Page_FromStageModel {
build() {
Column() {
//...
Button('打开 FuncAbilityB')
.onClick(() => {
let context: common.UIAbilityContext = getContext(this) as common.UIAbilityContext; // UIAbilityContext
// 在FuncAbility中通过调用terminateSelf()方法实现。
// context为需要停止的UIAbility实例的AbilityContext
let wantInfo: Want = {
deviceId: '', // deviceId为空表示本设备
bundleName: 'com.example.learnharmonyos',
moduleName: 'entry', // moduleName非必选
abilityName: 'FuncAbilityB',
parameters: {
// 自定义信息
info: '来自EntryAbility Page_FromStageModel'
},
}
context.startAbility(wantInfo).then(() => {
hilog.info(DOMAIN_NUMBER, TAG, 'startAbility FuncAbilityB success.');
}).catch((error: BusinessError) => {
hilog.error(DOMAIN_NUMBER, TAG, 'startAbility FuncAbilityB failed.');
})
context.terminateSelf((err) => {
if (err.code) {
hilog.error(DOMAIN_NUMBER, TAG,
`Failed to terminate self. Code is ${err.code}, message is ${err.message}`);
return;
}
});
})
}
//...
}
}
运行效果图
说明调用terminateSelf()方法停止当前UIAbility实例时,默认会保留该实例的快照(Snapshot),即在最近任务列表中仍然能查看到该实例对应的任务。如不需要保留该实例的快照,可以在其对应UIAbility的module.json5配置文件中,将abilities标签的removeMissionAfterTerminate字段配置为true。
4.如需要关闭应用所有的UIAbility实例,可以调用ApplicationContext的killAllProcesses()方法实现关闭应用所有的进程。
二、启动应用内的UIAbility并获取返回结果
在一个EntryAbility启动另外一个FuncAbility时,希望在被启动的FuncAbility完成相关业务后,能将结果返回给调用方。例如在应用中将入口功能和账号登录功能分别设计为两个独立的UIAbility,在账号登录UIAbility中完成登录操作后,需要将登录的结果返回给入口UIAbility。
1.在EntryAbility中,调用startAbilityForResult()接口启动FuncAbility,异步回调中的data用于接收FuncAbility停止自身后返回给EntryAbility的信息。示例中的context的获取方式请参见获取UIAbility的上下文信息。
bash
// UIAbility组件间交互(设备内)https://developer.huawei.com/consumer/cn/training/course/slightMooc/C101717497122909477
import { common, Want } from '@kit.AbilityKit';
import { hilog } from '@kit.PerformanceAnalysisKit';
import { promptAction } from '@kit.ArkUI';
import { BusinessError } from '@kit.BasicServicesKit';
const TAG: string = '[Page_UIAbilityComponentsInteractive]';
const DOMAIN_NUMBER: number = 0xFF00;
@Entry
@Component
struct Page_UIAbilityComponentsInteractive {
private context = getContext(this) as common.UIAbilityContext;
build() {
Column() {
//...
List({ initialIndex: 0 }) {
ListItem() {
Row() {
Text('打开 FuncAbilityA')
.fontSize(20)
.fontWeight(FontWeight.Medium)
.margin({ top: 20 })
}
.onClick(() => {
// this.testStartAbilityParameters()
this.testStartAbilityForResult()
})
}
//...
}
//...
}
//...
}
private wantInfo: Want = {
deviceId: '', // deviceId为空表示本设备
bundleName: 'com.example.learnharmonyos',
moduleName: 'entry', // moduleName非必选
abilityName: 'FuncAbilityA',
parameters: {
// 自定义信息
info: '来自EntryAbility Page_UIAbilityComponentsInteractive页面'
},
};
testStartAbilityParameters(): void {
// context为Ability对象的成员,在非Ability对象内部调用需要
// 将Context对象传递过去
// context为调用方UIAbility的UIAbilityContext
this.context.startAbility(this.wantInfo).then(() => {
hilog.info(DOMAIN_NUMBER, TAG, 'startAbility success.');
}).catch((error: BusinessError) => {
hilog.error(DOMAIN_NUMBER, TAG, 'startAbility failed.');
});
}
testStartAbilityForResult(): void {
const RESULT_CODE: number = 1001;
this.context.startAbilityForResult(this.wantInfo).then((data) => {
if (data?.resultCode === RESULT_CODE) {
// 解析被调用方UIAbility返回的信息
let info = data.want?.parameters?.info;
hilog.info(DOMAIN_NUMBER, TAG, JSON.stringify(info) ?? '');
if (info !== null) {
promptAction.showToast({
message: JSON.stringify(info)
});
}
}
hilog.info(DOMAIN_NUMBER, TAG, JSON.stringify(data.resultCode) ?? '');
}).catch((err: BusinessError) => {
hilog.error(DOMAIN_NUMBER, TAG,
`Failed to start ability for result. Code is ${err.code}, message is ${err.message}`);
});
}
}
2.在FuncAbility停止自身时,需要调用terminateSelfWithResult()方法,入参abilityResult为FuncAbility需要返回给EntryAbility的信息。
bash
import { common } from '@kit.AbilityKit';
import { hilog } from '@kit.PerformanceAnalysisKit';
const TAG: string = '[Page_FuncAbilityA]';
const DOMAIN_NUMBER: number = 0xFF00;
@Entry
@Component
struct Page_FuncAbilityA {
build() {
Column() {
//...
List({ initialIndex: 0 }) {
ListItem() {
Row() {
Text('Page_FuncAbilityA页面')
.fontSize(16)
.fontWeight(FontWeight.Normal)
.margin({ top: 20 })
}
.onClick(() => {
let context: common.UIAbilityContext = getContext(this) as common.UIAbilityContext; // UIAbilityContext
const RESULT_CODE: number = 1001;
let abilityResult: common.AbilityResult = {
resultCode: RESULT_CODE,
want: {
bundleName: 'com.example.learnharmonyos',
moduleName: 'entry', // moduleName非必选
abilityName: 'FuncAbilityB',
parameters: {
info: '来自 Page_FuncAbilityA Index页面'
},
},
};
context.terminateSelfWithResult(abilityResult, (err) => {
if (err.code) {
hilog.error(DOMAIN_NUMBER, TAG,
`Failed to terminate self with result. Code is ${err.code}, message is ${err.message}`);
return;
}
});
})
}
//...
}
//...
}
//...
}
}
3.FuncAbility停止自身后,EntryAbility通过startAbilityForResult()方法回调接收被FuncAbility返回的信息,RESULT_CODE需要与前面的数值保持一致。
运行效果图
三、启动UIAbility的指定页面
3.1 概述
一个UIAbility可以对应多个页面,在不同的场景下启动该UIAbility时需要展示不同的页面,例如从一个UIAbility的页面中跳转到另外一个UIAbility时,希望启动目标UIAbility的指定页面。
UIAbility的启动分为两种情况:UIAbility冷启动和UIAbility热启动。
- UIAbility冷启动:指的是UIAbility实例处于完全关闭状态下被启动,这需要完整地加载和初始化UIAbility实例的代码、资源等。
- UIAbility热启动:指的是UIAbility实例已经启动并在前台运行过,由于某些原因切换到后台,再次启动该UIAbility实例,这种情况下可以快速恢复UIAbility实例的状态。
下文主要讲解目标UIAbility冷启动和目标UIAbility热启动两种启动指定页面的场景,以及在讲解启动指定页面之前会讲解到在调用方如何指定启动页面。
3.2 调用方UIAbility指定启动页面
调用方UIAbility启动另外一个UIAbility时,通常需要跳转到指定的页面。例如FuncAbility包含两个页面(Index对应首页,Second对应功能A页面),此时需要在传入的want参数中配置指定的页面路径信息,可以通过want中的parameters参数增加一个自定义参数传递页面跳转信息。示例中的context的获取方式请参见获取UIAbility的上下文信息。
bash
// UIAbility组件间交互(设备内)https://developer.huawei.com/consumer/cn/training/course/slightMooc/C101717497122909477
import { common, Want } from '@kit.AbilityKit';
import { hilog } from '@kit.PerformanceAnalysisKit';
import { promptAction } from '@kit.ArkUI';
import { BusinessError } from '@kit.BasicServicesKit';
const TAG: string = '[Page_UIAbilityComponentsInteractive]';
const DOMAIN_NUMBER: number = 0xFF00;
@Entry
@Component
struct Page_UIAbilityComponentsInteractive {
private context = getContext(this) as common.UIAbilityContext;
build() {
Column() {
//...
List({ initialIndex: 0 }) {
ListItem() {
Row() {
Text('打开 FuncAbilityA')
.fontSize(20)
.fontWeight(FontWeight.Medium)
.margin({ top: 20 })
}
.onClick(() => {
// this.testStartAbilityParameters()
// this.testStartAbilityForResult()
this.testStartAbilityParametersRouter()
})
}
//...
}
//...
}
//...
}
private wantInfo: Want = {
deviceId: '', // deviceId为空表示本设备
bundleName: 'com.example.learnharmonyos',
moduleName: 'entry', // moduleName非必选
abilityName: 'FuncAbilityA',
parameters: {
router:'SecondFuncA',
// 自定义信息
info: '来自EntryAbility Page_UIAbilityComponentsInteractive页面'
},
};
testStartAbilityParameters(): void {
// context为Ability对象的成员,在非Ability对象内部调用需要
// 将Context对象传递过去
// context为调用方UIAbility的UIAbilityContext
this.context.startAbility(this.wantInfo).then(() => {
hilog.info(DOMAIN_NUMBER, TAG, 'startAbility success.');
}).catch((error: BusinessError) => {
hilog.error(DOMAIN_NUMBER, TAG, 'startAbility failed.');
});
}
testStartAbilityForResult(): void {
const RESULT_CODE: number = 1001;
this.context.startAbilityForResult(this.wantInfo).then((data) => {
if (data?.resultCode === RESULT_CODE) {
// 解析被调用方UIAbility返回的信息
let info = data.want?.parameters?.info;
hilog.info(DOMAIN_NUMBER, TAG, JSON.stringify(info) ?? '');
if (info !== null) {
promptAction.showToast({
message: JSON.stringify(info)
});
}
}
hilog.info(DOMAIN_NUMBER, TAG, JSON.stringify(data.resultCode) ?? '');
}).catch((err: BusinessError) => {
hilog.error(DOMAIN_NUMBER, TAG,
`Failed to start ability for result. Code is ${err.code}, message is ${err.message}`);
});
}
testStartAbilityParametersRouter(): void {
this.context.startAbility(this.wantInfo).then(() => {
hilog.info(DOMAIN_NUMBER, TAG, 'startAbility success.');
}).catch((error: BusinessError) => {
hilog.error(DOMAIN_NUMBER, TAG, 'startAbility failed.');
});
}
}
3.3 目标UIAbility冷启动
目标UIAbility冷启动时,在目标UIAbility的onCreate()生命周期回调中,接收调用方传过来的参数。然后在目标UIAbility的onWindowStageCreate()生命周期回调中,解析调用方传递过来的want参数,获取到需要加载的页面信息url,传入windowStage.loadContent()方法。
bash
import { AbilityConstant, UIAbility, Want } from '@kit.AbilityKit';
import { hilog } from '@kit.PerformanceAnalysisKit';
import { window } from '@kit.ArkUI';
const TAG: string = '[FuncAbilityA]';
const DOMAIN_NUMBER: number = 0x0000;
export default class FuncAbilityA extends UIAbility {
funcAbilityWant: Want | undefined = undefined
onCreate(want: Want, launchParam: AbilityConstant.LaunchParam): void {
// 接收调用方UIAbility传过来的参数
this.funcAbilityWant = want;
let info = this.funcAbilityWant?.parameters?.info;
hilog.info(DOMAIN_NUMBER, TAG, '%{public}s', `Ability onCreate 接收到的参数 info = ${info}`);
}
onDestroy(): void {
hilog.info(DOMAIN_NUMBER, TAG, '%{public}s', 'Ability onDestroy');
}
onWindowStageCreate(windowStage: window.WindowStage): void {
// Main window is created, set main page for this ability
hilog.info(DOMAIN_NUMBER, TAG, '%{public}s', 'Ability onWindowStageCreate');
let url: string = 'pages/useuiability/Page_FuncAbilityA';
if (this.funcAbilityWant?.parameters?.router && this.funcAbilityWant.parameters.router === 'SecondFuncA') {
url = 'pages/useuiability/SecondFuncA';
}
windowStage.loadContent(url, (err) => {
if (err.code) {
hilog.error(DOMAIN_NUMBER, TAG, 'Failed to load the content. Cause: %{public}s', JSON.stringify(err) ?? '');
return;
}
hilog.info(DOMAIN_NUMBER, TAG, 'Succeeded in loading the content.');
});
}
onWindowStageDestroy(): void {
// Main window is destroyed, release UI related resources
hilog.info(DOMAIN_NUMBER, TAG, '%{public}s', 'Ability onWindowStageDestroy');
}
onForeground(): void {
// Ability has brought to foreground
hilog.info(DOMAIN_NUMBER, TAG, '%{public}s', 'Ability onForeground');
}
onBackground(): void {
// Ability has back to background
hilog.info(DOMAIN_NUMBER, TAG, '%{public}s', 'Ability onBackground');
}
}
3.4 目标UIAbility热启动
在应用开发中,会遇到目标UIAbility实例之前已经启动过的场景,这时再次启动目标UIAbility时,不会重新走初始化逻辑,只会直接触发onNewWant()生命周期方法。为了实现跳转到指定页面,需要在onNewWant()中解析参数进行处理。
例如短信应用和联系人应用配合使用的场景。
- 用户先打开短信应用,短信应用的UIAbility实例启动,显示短信应用的主页。
- 用户将设备回到桌面界面,短信应用进入后台运行状态。
- 用户打开联系人应用,找到联系人张三。
- 用户点击联系人张三的短信按钮,会重新启动短信应用的UIAbility实例。
- 由于短信应用的UIAbility实例已经启动过了,此时会触发该UIAbility的onNewWant()回调,而不会再走onCreate()和onWindowStageCreate()等初始化逻辑。
目标UIAbility热启动流程图
1.冷启动短信应用的UIAbility实例时,在onWindowStageCreate()生命周期回调中,通过调用getUIContext()接口获取UI上下文实例UIContext对象。
bash
// UIAbility组件间交互(设备内)https://developer.huawei.com/consumer/cn/training/course/slightMooc/C101717497122909477
import { AbilityConstant, UIAbility, Want } from '@kit.AbilityKit';
import { hilog } from '@kit.PerformanceAnalysisKit';
import { window } from '@kit.ArkUI';
const TAG: string = '[FuncAbilityA]';
const DOMAIN_NUMBER: number = 0x0000;
export default class FuncAbilityA extends UIAbility {
funcAbilityWant: Want | undefined = undefined
uiContext: UIContext | undefined = undefined;
onCreate(want: Want, launchParam: AbilityConstant.LaunchParam): void {
// 接收调用方UIAbility传过来的参数
this.funcAbilityWant = want;
let info = this.funcAbilityWant?.parameters?.info;
hilog.info(DOMAIN_NUMBER, TAG, '%{public}s', `Ability onCreate 接收到的参数 info = ${info}`);
}
onDestroy(): void {
hilog.info(DOMAIN_NUMBER, TAG, '%{public}s', 'Ability onDestroy');
}
onWindowStageCreate(windowStage: window.WindowStage): void {
// Main window is created, set main page for this ability
hilog.info(DOMAIN_NUMBER, TAG, '%{public}s', 'Ability onWindowStageCreate');
// 目标UIAbility冷启动
// 目标UIAbility冷启动时,在目标UIAbility的onCreate()生命周期回调中,接收调用方传过来的参数。
// 然后在目标UIAbility的onWindowStageCreate()生命周期回调中,解析调用方传递过来的want参数,获取到需要加载的页面信息url,传入windowStage.loadContent()方法。
let url: string = 'pages/useuiability/Page_FuncAbilityA';
if (this.funcAbilityWant?.parameters?.router && this.funcAbilityWant.parameters.router === 'SecondFuncA') {
url = 'pages/useuiability/SecondFuncA';
}
windowStage.loadContent(url, (err) => {
if (err.code) {
hilog.error(DOMAIN_NUMBER, TAG, 'Failed to load the content. Cause: %{public}s', JSON.stringify(err) ?? '');
return;
}
//冷启动短信应用的UIAbility实例时,在onWindowStageCreate()生命周期回调中,通过调用getUIContext()接口获取UI上下文实例UIContext对象。
let windowClass: window.Window
windowStage.getMainWindow((err, data) =>{
if (err.code) {
hilog.error(DOMAIN_NUMBER, TAG, `Failed to obtain the main window. Code is ${err.code}, message is ${err.message}`);
return;
}
windowClass = data;
this.uiContext = windowClass.getUIContext();
})
hilog.info(DOMAIN_NUMBER, TAG, 'Succeeded in loading the content.');
});
}
onWindowStageDestroy(): void {
// Main window is destroyed, release UI related resources
hilog.info(DOMAIN_NUMBER, TAG, '%{public}s', 'Ability onWindowStageDestroy');
}
onForeground(): void {
// Ability has brought to foreground
hilog.info(DOMAIN_NUMBER, TAG, '%{public}s', 'Ability onForeground');
}
onBackground(): void {
// Ability has back to background
hilog.info(DOMAIN_NUMBER, TAG, '%{public}s', 'Ability onBackground');
}
}
2.在短信应用UIAbility的onNewWant()回调中解析调用方传递过来的want参数,通过调用UIContext中的getRouter()方法获取Router对象,并进行指定页面的跳转。此时再次启动该短信应用的UIAbility实例时,即可跳转到该短信应用的UIAbility实例的指定页面。
bash
import { AbilityConstant, Want, UIAbility } from '@kit.AbilityKit';
import { hilog } from '@kit.PerformanceAnalysisKit';
import type { Router, UIContext } from '@kit.ArkUI';
import type { BusinessError } from '@kit.BasicServicesKit';
const DOMAIN_NUMBER: number = 0xFF00;
const TAG: string = '[EntryAbility]';
export default class EntryAbility extends UIAbility {
funcAbilityWant: Want | undefined = undefined;
uiContext: UIContext | undefined = undefined;
// ...
onNewWant(want: Want, launchParam: AbilityConstant.LaunchParam): void {
if (want?.parameters?.router && want.parameters.router === 'funcA') {
let funcAUrl = 'pages/Page_HotStartUp';
if (this.uiContext) {
let router: Router = this.uiContext.getRouter();
router.pushUrl({
url: funcAUrl
}).catch((err: BusinessError) => {
hilog.error(DOMAIN_NUMBER, TAG, `Failed to push url. Code is ${err.code}, message is ${err.message}`);
});
}
}
}
}
说明
当被调用方UIAbility组件启动模式设置为multiton启动模式时,每次启动都会创建一个新的实例,那么onNewWant()回调就不会被用到。