1e41f4b71Sopenharmony_ci# MediaLibrary_RequestId 2e41f4b71Sopenharmony_ci 3e41f4b71Sopenharmony_ci 4e41f4b71Sopenharmony_ci## 概述 5e41f4b71Sopenharmony_ci 6e41f4b71Sopenharmony_ci定义请求Id。 7e41f4b71Sopenharmony_ci 8e41f4b71Sopenharmony_ci当请求媒体库资源时，会返回此类型。 请求Id用于取消请求。 如果请求失败，值将全为零，如 "00000000-0000-0000-0000-000000000000"。 9e41f4b71Sopenharmony_ci 10e41f4b71Sopenharmony_ci**起始版本：** 12 11e41f4b71Sopenharmony_ci 12e41f4b71Sopenharmony_ci**相关模块：**[MediaAssetManager](_media_asset_manager.md) 13e41f4b71Sopenharmony_ci 14e41f4b71Sopenharmony_ci 15e41f4b71Sopenharmony_ci## 汇总 16e41f4b71Sopenharmony_ci 17e41f4b71Sopenharmony_ci 18e41f4b71Sopenharmony_ci### 成员变量 19e41f4b71Sopenharmony_ci 20e41f4b71Sopenharmony_ci| 名称 | 描述 | 21e41f4b71Sopenharmony_ci| -------- | -------- | 22e41f4b71Sopenharmony_ci| char [requestId](#requestid) [UUID_STR_MAX_LENGTH] | 定义UUID最大长度。 | 23e41f4b71Sopenharmony_ci 24e41f4b71Sopenharmony_ci 25e41f4b71Sopenharmony_ci## 结构体成员变量说明 26e41f4b71Sopenharmony_ci 27e41f4b71Sopenharmony_ci 28e41f4b71Sopenharmony_ci### requestId 29e41f4b71Sopenharmony_ci 30e41f4b71Sopenharmony_ci``` 31e41f4b71Sopenharmony_cichar MediaLibrary_RequestId::requestId[UUID_STR_MAX_LENGTH] 32e41f4b71Sopenharmony_ci``` 33e41f4b71Sopenharmony_ci**描述** 34e41f4b71Sopenharmony_ci定义UUID最大长度。 35