做手机网站版面做多宽,长春网络安全公司,网站运维托管,电子商务网站建设人才1. UIAbility组件生命周期
UIAbility的生命周期包括Create、Foreground、Background、Destroy四个状态。
UIAbility生命周期状态 1.1 Create状态
Create状态为在应用加载过程中#xff0c;UIAbility实例创建完成时触发#xff0c;系统会调用onCreate()回调。可以在该回调中…1. UIAbility组件生命周期
UIAbility的生命周期包括Create、Foreground、Background、Destroy四个状态。
UIAbility生命周期状态 1.1 Create状态
Create状态为在应用加载过程中UIAbility实例创建完成时触发系统会调用onCreate()回调。可以在该回调中进行页面初始化操作例如变量定义资源加载等用于后续的UI界面展示。
import UIAbility from ohos.app.ability.UIAbility;
import Window from ohos.window;export default class EntryAbility extends UIAbility {onCreate(want, launchParam) {// 页面初始化}// ...
}
1.2 WindowStageCreate和WindowStageDestroy状态
UIAbility实例创建完成之后在进入Foreground之前系统会创建一个WindowStage。WindowStage创建完成后会进入onWindowStageCreate()回调可以在该回调中设置UI界面加载、设置WindowStage的事件订阅。 在onWindowStageCreate()回调中通过loadContent()方法设置应用要加载的页面并根据需要订阅WindowStage的事件获焦/失焦、可见/不可见。
import UIAbility from ohos.app.ability.UIAbility;
import Window from ohos.window;export default class EntryAbility extends UIAbility {onWindowStageCreate(windowStage: Window.WindowStage) {// 设置WindowStage的事件订阅获焦/失焦、可见/不可见// 设置UI界面加载windowStage.loadContent(pages/Index, (err, data) {// ...});}
}
在UIAbility实例销毁之前会进入onWindowStageDestroy()回调可以释放UI界面资源。
import UIAbility from ohos.app.ability.UIAbility;
import Window from ohos.window;export default class EntryAbility extends UIAbility {// ...onWindowStageDestroy() {// 释放UI界面资源}
}
onCreate在 Ability 创建时被调用用于执行初始化和设置业务逻辑。onDestroy在 Ability 销毁时触发用于执行资源清理和其他清理操作。onWindowStageCreate在 WindowStage 创建完成后触发。onWindowStageDestroy在 WindowStage 销毁后触发。onForegroundAbility 的生命周期回调当应用从后台切换到前台时调用。onBackgroundAbility 的生命周期回调当应用从前台切换到后台时调用。
2. 页面和自定义组件生命周期
2.1 页面生命周期
即被Entry装饰的组件生命周期提供以下生命周期接口
onPageShow页面每次显示时触发一次包括路由过程、应用进入前台等场景。onPageHide页面每次隐藏时触发一次包括路由过程、应用进入后台等场景。onBackPress当用户点击返回按钮时触发。
2.2 组件生命周期
即一般用Component装饰的自定义组件的生命周期提供以下生命周期接口
aboutToAppear组件即将出现时回调该接口具体时机为在创建自定义组件的新实例后在执行其build()函数之前执行。aboutToDisappear在自定义组件析构销毁之前执行。不允许在aboutToDisappear函数中改变状态变量特别是Link变量的修改可能会导致应用程序行为不稳定。
2.3 生命周期流程
下图展示的是被Entry装饰的组件页面生命周期。 2.4 自定义组件的渲染流程
ArkUI框架创建自定义组件初始化自定义组件的成员变量执行aboutToAppear方法执行build方法渲染组件在首次渲染时框架会记录状态变量和组件的映射关系当状态变量的值更改时框架根据映射关系执行这些UI组件的更新函数if分支或者ForEach渲染的数组个数改变组件将被删除在删除前执行aboutToDisappear 不建议在aboutToDisappear内使用async await如果在aboutToDisappear使用中Promise或者回调方法自定义组件将被保留在Promise的闭包中直到回调方法被执行完这个行为阻止了自定义组件的垃圾回收。 2.5 示例
import router from ohos.routerEntry
Component
struct Index {State showChild: boolean true;// 页面生命周期onPageShow() {console.info(Index onPageShow);}// 页面生命周期onPageHide() {console.info(Index onPageHide);}// 页面生命周期onBackPress() {console.info(Index onBackPress);}// 组件生命周期aboutToAppear() {console.info(Index aboutToAppear);}// 组件生命周期aboutToDisappear() {console.info(Index aboutToDisappear);}build() {Column() {// this.showChild为true创建Child子组件执行Child aboutToAppearif (this.showChild) {Child()}// this.showChild为false删除Child子组件执行Child aboutToDisappearButton(删除子组件 Child).margin({ bottom: 20 }).onClick(() {this.showChild false;})// push到DetailPage页面执行onPageHideButton(跳转到 DetailPage).onClick(() {router.pushUrl({ url: pages/DetailPage });})}.width(100%).height(100%)}
}Component
struct Child {State title: string Child;// 组件生命周期aboutToAppear() {console.info(Child aboutToAppear)}// 组件生命周期aboutToDisappear() {console.info(Child aboutToDisappear)}build() {Text(this.title).fontSize(50).onClick(() {this.title Child Click;})}
}
3. 同模块下的UIAbility跳转
3.1 创建 PaymentPage Entry
Component
struct PaymentPage {State message: string payment pagebuild() {Row() {Column() {Text(this.message).fontSize(50).fontWeight(FontWeight.Bold)}.width(100%)}.height(100%)}
}
3.2 创建 PaymentAbility 修改 windowStage.loadContent 加载的页面 3.3 修改 Index.ets
import common from ohos.app.ability.common
import Want from ohos.app.ability.WantEntry
Component
struct Index {State message: string index pagebuild() {Row() {Column() {Text(this.message).fontSize(50).fontWeight(FontWeight.Bold)Button(去支付).width(100%).onClick(() {const context getContext(this) as common.UIAbilityContext;const want: Want {deviceId: , // deviceId为空表示本设备bundleName: com.example.myapplication,abilityName: PaymentAbility,moduleName: entry}context.startAbility(want)})}.width(100%)}.height(100%)}
} 4. 不同模块下的UIAbility跳转
4.1 创建模块 4.2 修改 paymentModule 模块的 Index.ets
Entry
Component
struct Index {State message: string payment module pagebuild() {Row() {Column() {Text(this.message).fontSize(50).fontWeight(FontWeight.Bold)}.width(100%)}.height(100%)}
}
4.3 修改 entry 模块的 Index.ets
修改 abilityName 和 moduleName import common from ohos.app.ability.common
import Want from ohos.app.ability.WantEntry
Component
struct Index {State message: string index pagebuild() {Row() {Column() {Text(this.message).fontSize(50).fontWeight(FontWeight.Bold)Button(去支付).width(100%).onClick(() {const context getContext(this) as common.UIAbilityContext;const want: Want {deviceId: , // deviceId为空表示本设备bundleName: com.example.myapplication,abilityName: PaymentModuleAbility,moduleName: paymentModule}context.startAbility(want)})}.width(100%)}.height(100%)}
}
4.4 配置调起2个模块 4.5 两个模块之间传递数据
4.5.1 修改 entry 模块的 Index.ets
使用 parameters 选项添加自定义数据
使用 context.startAbilityForResult 方法启动 UIAbility 并获取返回结果 import common from ohos.app.ability.common
import Want from ohos.app.ability.Wanttype PaymentAbilityParams Recordstring, booleanEntry
Component
struct Index {State message: string index pagebuild() {Row() {Column() {Text(this.message).fontSize(50).fontWeight(FontWeight.Bold)Button(去支付).width(100%).onClick(async () {const context getContext(this) as common.UIAbilityContext;const want: Want {deviceId: , // deviceId为空表示本设备bundleName: com.example.myapplication,abilityName: PaymentModuleAbility,moduleName: paymentModule,parameters: {orderId: Date.now()}}// context.startAbility(want)const paymentAbilityResult await context.startAbilityForResult(want)const params paymentAbilityResult.want?.parameters as PaymentAbilityParamsif (params?.isPay) {AlertDialog.show({message: 支付成功})} else {AlertDialog.show({message: 支付失败})}})}.width(100%)}.height(100%)}
}
4.5.2 修改 paymentModule 模块的 PaymentModuleAbility
在 UIAbility 的 onCreate 中接收参数并保存到 AppStorage 中 import UIAbility from ohos.app.ability.UIAbility;
import hilog from ohos.hilog;
import window from ohos.window;type AbilityParams Recordstring, numberexport default class PaymentModuleAbility extends UIAbility {onCreate(want, launchParam) {const params want.parameters as AbilityParams;AppStorage.SetOrCreatenumber(orderId, params.orderId);hilog.info(0x0000, testTag, %{public}s, Ability onCreate);}onDestroy() {hilog.info(0x0000, testTag, %{public}s, Ability onDestroy);}onWindowStageCreate(windowStage: window.WindowStage) {// Main window is created, set main page for this abilityhilog.info(0x0000, testTag, %{public}s, Ability onWindowStageCreate);windowStage.loadContent(pages/Index, (err, data) {if (err.code) {hilog.error(0x0000, testTag, Failed to load the content. Cause: %{public}s, JSON.stringify(err) ?? );return;}hilog.info(0x0000, testTag, Succeeded in loading the content. Data: %{public}s, JSON.stringify(data) ?? );});}onWindowStageDestroy() {// Main window is destroyed, release UI related resourceshilog.info(0x0000, testTag, %{public}s, Ability onWindowStageDestroy);}onForeground() {// Ability has brought to foregroundhilog.info(0x0000, testTag, %{public}s, Ability onForeground);}onBackground() {// Ability has back to backgroundhilog.info(0x0000, testTag, %{public}s, Ability onBackground);}
}4.5.3 修改 paymentModule 模块的 Index.ets
从 storage 中获取 orderId
点击支付按钮 PaymentModuleAbility 停止自身并返回结果 import common from ohos.app.ability.commonEntry
Component
struct Index {State message: string payment module pageStorageProp(orderId) orderId: number 0build() {Row() {Column() {Text(this.message).fontSize(50).fontWeight(FontWeight.Bold)Text(${this.orderId}).fontSize(50).fontColor(Color.Red)Button(支付).onClick(() {const context getContext(this) as common.UIAbilityContext;context.terminateSelfWithResult({resultCode: 1,want: {deviceId: , // deviceId为空表示本设备bundleName: com.example.myapplications,abilityName: EntryAbility,moduleName: entry,parameters: {isPay: true}}})})}.width(100%)}.height(100%)}
}
