授权持久化(C/C++)

场景介绍

应用通过Picker获取临时授权，临时授权在应用退出后或者设备重启后会清除。如果应用重启或者设备重启后需要直接访问之前已访问过的文件，则对文件进行持久化授权。FileShare提供了支持基于uri的文件及目录授予持久化权限、权限激活、权限查询等方法。

接口说明

接口的详细介绍请参见oh_file_uri.h。

接口名称	描述
OH_FileShare_PersistPermission(const FileShare_PolicyInfo policies, unsigned int policyNum, FileShare_PolicyErrorResult result, unsigned int resultNum)	对所选择的多个文件或目录uri持久化授权。
OH_FileShare_RevokePermission(const FileShare_PolicyInfo policies, unsigned int policyNum, FileShare_PolicyErrorResult result, unsigned int resultNum)	对所选择的多个文件或目录uri取消持久化授权。
OH_FileShare_ActivatePermission(const FileShare_PolicyInfo policies, unsigned int policyNum, FileShare_PolicyErrorResult result, unsigned int resultNum)	使能多个已经持久化授权过的文件或目录uri。
OH_FileShare_DeactivatePermission(const FileShare_PolicyInfo policies, unsigned int policyNum, FileShare_PolicyErrorResult result, unsigned int resultNum)	取消使能授权过的多个文件或目录uri。
OH_FileShare_CheckPersistentPermission(const FileShare_PolicyInfo policies, unsigned int policyNum, bool result, unsigned int resultNum)	校验所选择的多个文件或目录uri的持久化权限结果。
OH_FileShare_ReleasePolicyErrorResult(FileShare_PolicyErrorResult *errorResult, unsigned int resultNum)	释放FileShare_PolicyErrorResult内存。

约束与限制

使用文件分享的相关接口，需确认设备具有以下系统能力：SystemCapability.FileManagement.AppFileService.FolderAuthorization。
在调用文件分享的相关接口前，需要申请权限："ohos.permission.FILE_ACCESS_PERSIST"，申请方式请参考选择申请权限的方式。

开发步骤

以下步骤描述了如何使用FileShare提供的Native API接口。

添加动态链接库

CMakeLists.txt中添加以下lib。

target_link_libraries(sample PUBLIC libohfileshare.so)

头文件

#include <filemanagement/fileshare/oh_file_share.h>
#include <iostream>

创建FileShare_PolicyInfo实例,调用OH_FileShare_PersistPermission接口，设置uri的持久化授权，接口入参policyNum最大上限为500。

static const uint32_t policyNum = 2;
char strTestPath1[] = "file://com.example.fileshare/data/storage/el2/base/files/test1.txt";
char strTestPath2[] = "file://com.example.fileshare/data/storage/el2/base/files/test2.txt";
FileShare_PolicyInfo policy[policyNum] = {
    {strTestPath1, static_cast<unsigned int>(strlen(strTestPath1)), FileShare_OperationMode::READ_MODE},
    {strTestPath2, static_cast<unsigned int>(strlen(strTestPath2)), FileShare_OperationMode::WRITE_MODE}};
FileShare_PolicyErrorResult* result = nullptr;
uint32_t resultNum = 0;
napi_value napiResult;
std::string resultStr;
auto ret = OH_FileShare_PersistPermission(policy, policyNum, &result, &resultNum);
if (ret != ERR_OK) {
    if (ret == ERR_EPERM && result != nullptr) {
        for (uint32_t i = 0; i < resultNum; i++) {
            std::cout << "error uri: " <<  result[i].uri << std::endl;
            std::cout << "error code: " <<  result[i].code << std::endl;
            std::cout << "error message: " << result[i].message << std::endl;
            // ...
        }
    }
}
OH_FileShare_ReleasePolicyErrorResult(result, resultNum);

调用OH_FileShare_ActivatePermission接口，激活已授权过的uri，接口入参policyNum最大上限为500。

auto ret = OH_FileShare_ActivatePermission(policy, policyNum, &result, &resultNum);
if (ret != ERR_OK) {
    if (ret == ERR_EPERM && result != nullptr) {
        for (uint32_t i = 0; i < resultNum; i++) {
            std::cout << "error uri: " <<  result[i].uri << std::endl;
            std::cout << "error code: " <<  result[i].code << std::endl;
            std::cout << "error message: " << result[i].message << std::endl;
            // ...
        }
    }
}
OH_FileShare_ReleasePolicyErrorResult(result, resultNum);

调用OH_FileShare_DeactivatePermission接口，停止已启用授权过uri的访问权限，接口入参policyNum最大上限为500。

auto ret = OH_FileShare_DeactivatePermission(policy, policyNum, &result, &resultNum);
if (ret != ERR_OK) {
    if (ret == ERR_EPERM && result != nullptr) {
        for (uint32_t i = 0; i < resultNum; i++) {
            std::cout << "error uri: " <<  result[i].uri << std::endl;
            std::cout << "error code: " <<  result[i].code << std::endl;
            std::cout << "error message: " << result[i].message << std::endl;
            // ...
        }
    }
}
OH_FileShare_ReleasePolicyErrorResult(result, resultNum);

调用OH_FileShare_RevokePermission接口，撤销已经授权的uri持久化权限，接口入参policyNum最大上限为500。

auto ret = OH_FileShare_RevokePermission(policy, policyNum, &result, &resultNum);
if (ret != ERR_OK) {
    if (ret == ERR_EPERM && result != nullptr) {
        for (uint32_t i = 0; i < resultNum; i++) {
            std::cout << "error uri: " <<  result[i].uri << std::endl;
            std::cout << "error code: " <<  result[i].code << std::endl;
            std::cout << "error message: " << result[i].message << std::endl;
            // ...
        }
    }
}
OH_FileShare_ReleasePolicyErrorResult(result, resultNum);

调用OH_FileShare_CheckPersistentPermission接口，检查uri持久化权限，接口入参policyNum最大上限为500。

bool *result = nullptr;
auto ret = OH_FileShare_CheckPersistentPermission(policy, policyNum, &result, &resultNum);
if (ret != ERR_OK) {
    if (ret == ERR_EPERM && result != nullptr) {
        for (uint32_t i = 0; i < resultNum && resultNum <= policyNum; i++) {
            std::cout << "uri: " <<  policy[i].uri << std::endl;
            std::cout << "result: " <<  result[i] << std::endl;
            // ...
        }
    }
}
std::cout << "retCode: " <<  ret << std::endl;
free(result);

场景介绍​

接口说明​

约束与限制​

开发步骤​

场景介绍

接口说明

约束与限制

开发步骤