1# 启动远程PageAbility（仅对系统应用开放） 2 3 4启动远程PageAbility同样通过featureAbility中的startAbility接口实现。 5 6 7除引入'\@ohos.ability.featureAbility'外，还需引入'\@ohos.distributedHardware.deviceManager'，通过DeviceManager（该组件在OpenHarmony上提供帐号无关的分布式设备的认证组网能力）的getTrustedDeviceListSync接口（获取信任设备列表）获取远端的deviceId，写入want中，用于启动远程PageAbility。 8 9 10由于当前DeviceManager的getTrustedDeviceListSync接口仅对系统应用开放，故现阶段非系统应用无法获取其他设备信息，无远程启动设备选择入口，远程启动Ability开发。 11 12 13 **表1** featureAbility接口说明 14 15| 接口名 | 接口描述 | 16| -------- | -------- | 17| startAbility(parameter: StartAbilityParameter) | 启动Ability。 | 18| startAbilityForResult(parameter: StartAbilityParameter) | 启动Ability，并在该Ability被销毁时返回执行结果。 | 19 20 21 **表2** deviceManager接口说明 22 23| 接口名 | 接口描述 | 24| -------- | -------- | 25| getTrustedDeviceListSync(): Array<DeviceInfo> | 同步获取所有可信设备列表。 | 26 27 28在跨设备场景下，启动远程PageAbility首先需要向用户申请数据同步的权限，相关接口说明如下： 29 30 31 **表3** AtManager接口说明 32 33| 接口名 | 接口描述 | 34| -------- | -------- | 35| checkAccessToken(tokenID: number, permissionName: string)<br>: Promise<GrantStatus> | 校验应用是否授予权限。使用Promise异步回调。返回值GrantStatus。建议使用checkAccessToken代替verifyAccessToken（已废弃），verifyAccessToken从API version 9开始不再维护。 | 36 37 38 **表4** context接口说明 39 40| 接口名 | 接口描述 | 41| -------- | -------- | 42| requestPermissionsFromUser(permissions: Array<string>, <br>requestCode: number, resultCallback: AsyncCallback<<br>PermissionRequestResult>): void | 以callback形式从系统请求某些权限，详见对应[接口文档](../reference/apis/js-apis-inner-app-context.md#contextrequestpermissionsfromuser7-1)。 | 43 44 45如下示例代码展示了向用户申请数据同步权限的方法： 46 47```ts 48import abilityAccessCtrl from "@ohos.abilityAccessCtrl"; 49import featureAbility from '@ohos.ability.featureAbility'; 50import bundle from '@ohos.bundle.bundleManager'; 51async function RequestPermission() { 52 console.info('RequestPermission begin'); 53 let array: Array<string> = ["ohos.permission.DISTRIBUTED_DATASYNC"]; 54 let bundleFlag = 0; 55 let tokenID = undefined; 56 let userID = 100; 57 let appInfo = await bundle.getApplicationInfo('ohos.samples.etsDemo', bundleFlag, userID); 58 tokenID = appInfo.accessTokenId; 59 let atManager = abilityAccessCtrl.createAtManager(); 60 let requestPermissions: Array<string> = []; 61 for (let i = 0;i < array.length; i++) { 62 let result = await atManager.verifyAccessToken(tokenID, array[i]); 63 console.info("checkAccessToken result:" + JSON.stringify(result)); 64 if (result != abilityAccessCtrl.GrantStatus.PERMISSION_GRANTED) { 65 requestPermissions.push(array[i]); 66 } 67 } 68 console.info("requestPermissions:" + JSON.stringify(requestPermissions)); 69 if (requestPermissions.length == 0 || requestPermissions == []) { 70 return; 71 } 72 let context = featureAbility.getContext(); 73 context.requestPermissionsFromUser(requestPermissions, 1, (error, data)=>{ 74 console.info("data:" + JSON.stringify(data)); 75 console.info("data requestCode:" + data.requestCode); 76 console.info("data permissions:" + data.permissions); 77 console.info("data authResults:" + data.authResults); 78 }); 79 console.info('RequestPermission end'); 80} 81``` 82 83 84在获取数据同步权限后，需要获取可信设备列表，进行设备选择。 85 86 87 如下示例展示了通过getTrustedDeviceListSync获取可信设备列表，选择设备的方法。 88 89```ts 90import deviceManager from '@ohos.distributedHardware.deviceManager'; 91 92let dmClass; 93 94function getDeviceManager() { 95 deviceManager.createDeviceManager('ohos.example.distributedService', (error, dm) => { 96 if (error) { 97 console.info('create device manager failed with ' + error) 98 } 99 dmClass = dm; 100 }) 101} 102 103function getRemoteDeviceId() { 104 if (typeof dmClass === 'object' && dmClass != null) { 105 let list = dmClass.getTrustedDeviceListSync(); 106 if (typeof (list) == 'undefined' || typeof (list.length) == 'undefined') { 107 console.info("EntryAbility onButtonClick getRemoteDeviceId err: list is null"); 108 return; 109 } 110 console.info("EntryAbility onButtonClick getRemoteDeviceId success:" + list[0].deviceId); 111 return list[0].deviceId; 112 } else { 113 console.info("EntryAbility onButtonClick getRemoteDeviceId err: dmClass is null"); 114 } 115} 116``` 117 118 119设备选择完成后，通过调用startAbility接口，显式启动远程PageAbility。 120 121 122如下示例展示了通过startAbility显式启动远程PageAbility的方法。 123 124```ts 125import featureAbility from '@ohos.ability.featureAbility'; 126 127function onStartRemoteAbility() { 128 console.info('onStartRemoteAbility begin'); 129 let params; 130 let wantValue = { 131 bundleName: 'ohos.samples.etsDemo', 132 abilityName: 'ohos.samples.etsDemo.RemoteAbility', 133 deviceId: getRemoteDeviceId(), // getRemoteDeviceId的定义在前面的示例代码中 134 parameters: params 135 }; 136 console.info('onStartRemoteAbility want=' + JSON.stringify(wantValue)); 137 featureAbility.startAbility({ 138 want: wantValue 139 }).then((data) => { 140 console.info('onStartRemoteAbility finished, ' + JSON.stringify(data)); 141 }); 142 console.info('onStartRemoteAbility end'); 143} 144``` 145