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[Harmony OS] [ARK UI] ETS context basic operations

2022-08-03 04:42:00 【Huawei developers BBS】

在HarmonyOS开发中,‘权限申请’,‘权限检查’,‘获取版本信息’,‘获取包名’都是基本操作,今天学习一下怎么实现如下功能,主要分为‘Api说明’,‘代码实现’,‘运行效果’三个步骤进行描述

1. Api说明

1.1参考Ability上下文
1.2 context.verifyPermission
verifyPermission(permission: string, options?: PermissionOptions): Promise
检查指定进程是否存在指定的权限,options为可选参数,不设置时表示检查自身权限,使用Promise方式作为异步方法.
1.2.1请求参数
参数一permission：需要校验的权限
参数二options：包含pid,uid（常规应用使用不到,这里不做详细讲解）
1.2.2 返回类型
Promise：Promise形式返回结果.返回-1表示不具备当前检查权限,0表示有权限
1.2.3示例：

import ability_featureAbility from '@ohos.ability.featureAbility'

var context = ability_featureAbility.getContext();
let permission = "ohos.permission.INTERACT_ACROSS_LOCAL_ACCOUNTS";
context.verifyPermission(permission,(error, data)=>{      
    if (error) {
        console.error('Operation failed. Cause: ' + JSON.stringify(error));
        return;
    }
    console.info('Operation successful. Data:' + JSON.stringify(data))
})

1.3 context.requestPermissionsFromUser
requestPermissionsFromUser(permissions: Array, requestCode: number): Promise
向用户请求某些权限,在申请权限之前查询自身进程是否已被授予该权限（verifyPermission）,如果已有权限,则无需申请,否则需要申请权限.使用Promise方式作为异步方法.
1.3.1参数详解
参数一：permissions：请求授予的权限
参二：requestCode ：请求状态码与匹配应用程序对应的特定请求代码,取值范围：大于等于0
1.3.2返回值：Promise：回调函数,可以在回调函数中处理接口返回值,返回权限请求结果
1.3.3PermissionRequestResult属性详解
requestCode：得到返回的请求码,主要作用用于判断是哪个请求的权限的作用
permissions：请求权限集合
authResults：权限验证结果,返回-1表示不具备当前检查权限,0表示有权限
1.3.4示例

import ability_featureAbility from '@ohos.ability.featureAbility'

var context = ability_featureAbility.getContext();
let permissions = ["ohos.permission.INTERACT_ACROSS_LOCAL_ACCOUNTS","ohos.permission.INTERACT_ACROSS_LOCAL_ACCOUNTS_EXTENSION"];
let requestCode = 123
context.requestPermissionsFromUser(permissions, requestCode)     
.then((data) => {
    console.info('Operation successful. Data: ' + JSON.stringify(data));
}).catch((error) => {
    console.error('Operation failed. Cause: ' + JSON.stringify(error));
})

1.4.1 context.getAppVersionInfo
getAppVersionInfo():Promise
获取应用的版本信息,使用Promise方式作为异步方法.
1.4.2返回结果：Promise：返回应用版本信息.
AppVersionInfo参数详解
appName：应用名称
versionCode：应用版本号
versionName：应用版本名称
1.4.3准备资料需要在config.json中查找version标签,如下图所示

1.4.4 示例代码

import ability_featureAbility from '@ohos.ability.featureAbility'

var context = ability_featureAbility.getContext();
context.getAppVersionInfo()     
.then((data) => {
    console.info('Operation successful. Data: ' + JSON.stringify(data));
}).catch((error) => {
    console.error('Operation failed. Cause: ' + JSON.stringify(error));
})

1.5.1 context.getBundleName
getBundleName(): Promise
获取Ability的所属的包名信息,使用Promise方式作为异步方法.
返回值：Promise：Promise形式返回Ability的所属的包名信息.
1.5.2参考配置文件的元素的bundleName.效果如如下

2. 代码实现

2.1需要在config.json 注册权限,参考配置文件的元素的reqPermissions

2.2目前申请权限如下
2.2.1 ohos.permission.READ_USER_STORAGE
2.2.2 ohos.permission.CAMERA

2.2.3 全部代码

 import ability_featureAbility from '@ohos.ability.featureAbility'

@Entry
@Component
struct MyFeatureAbilityPage {
  private myVerifyPermission() {
    var context = ability_featureAbility.getContext();
    let permission = "ohos.permission.CAMERA";
    context.verifyPermission(permission, null)
      .then((data) => {
        if(data===-1){
          console.log('当前没有权限 ' );
        }else{
          console.log('当前已具备权限 ' );
        }
      }).catch((error) => {
      console.log('Operation failed. Cause: ' + JSON.stringify(error));
    })
  }

  private MyRequestPermissionsFromUser() {

    var context = ability_featureAbility.getContext();
    let permissions = ["ohos.permission.CAMERA","ohos.permission.READ_USER_STORAGE"];
    let requestCode = 123
    context.requestPermissionsFromUser(permissions, requestCode)
      .then((data) => {
        console.log("请求码"+data.requestCode)
        console.log("请求权限"+data.permissions.toString())
        if(requestCode===data.requestCode){//用于判断返回的请求码和申请的请求是否相同
            for(var i=0;i<data.permissions.length;i++){
              if(data.authResults[i]==-1){
                console.log("请求权限："+data.permissions[i]+"==>请求状态是拒绝")
              }else{
                console.log("请求权限："+data.permissions[i]+"==>请求状态是同意")
              }
            }
        }

      }).catch((error) => {
      console.log('Operation failed. Cause: ' + JSON.stringify(error));
    })
  }

  private MyGetAppVersionInfo() {
    var context = ability_featureAbility.getContext();
    context.getAppVersionInfo()
      .then((data) => {
        console.log("getAppVersionInfo===>应用名称:"+data.appName)
        console.log("getAppVersionInfo===>versionCode:"+data.versionCode)
        console.log("getAppVersionInfo===>versionName:"+data.versionName)
      }).catch((error) => {
      console.log('Operation failed. Cause: ' + JSON.stringify(error));
    })
  }

  private myGetBundleName() {
    var context = ability_featureAbility.getContext();
    context.getBundleName()
      .then((data) => {
        console.log('getBundleName包名: ' + JSON.stringify(data));
      }).catch((error) => {
      console.log('Operation failed. Cause: ' + JSON.stringify(error));
    })
  }


  build() {
    Flex({ direction: FlexDirection.Column, alignItems: ItemAlign.Center, justifyContent: FlexAlign.Center }) {
      Text('检查当前权限')
        .fontSize(50)
        .fontWeight(FontWeight.Bold)
        .onClick(this.myVerifyPermission.bind(this))

      Text('申请权限')
        .fontSize(50)
        .fontWeight(FontWeight.Bold)
        .onClick(this.MyRequestPermissionsFromUser.bind(this))
      .backgroundColor(Color.Red)

      Text('获取版本信息')
        .fontSize(50)
        .fontWeight(FontWeight.Bold)
        .onClick(this.MyGetAppVersionInfo.bind(this))

      Text('获取包名')
        .fontSize(50)
        .fontWeight(FontWeight.Bold)
        .onClick(this.myGetBundleName.bind(this))
      .backgroundColor(Color.Red)



    }
    .width('100%')
    .height('100%')
  }
}