#鸿蒙通关秘籍#如何在HarmonyOS中使用Sendable进行大容量数据库操作？

在鸿蒙开发中，当需要跨线程传递大量数据库数据时，可以使用Sendable来封装数据，以降低线程间的数据传递耗时。具体步骤如下：

1. 定义数据库中数据格式并使用Sendable： typescript export interface IValueBucket { id: number name: string age: number salary: number }

@Sendable export class SharedValuesBucket implements IValueBucket { id: number = 0 name: string = "" age: number = 0 salary: number = 0

constructor(v: IValueBucket) { this.id = v.id; this.name = v.name; this.age = v.age; this.salary = v.salary; } }

2. 子线程进行数据处理，如增删改查： typescript @Concurrent async function query(context: Context): Promise<collections.Array<SharedValuesBucket | undefined>> { const CONFIG: relationalStore.StoreConfig = { name: "Store.db", securityLevel: relationalStore.SecurityLevel.S1, }; let store: relationalStore.RdbStore = await relationalStore.getRdbStore(context, CONFIG); let predicates: relationalStore.RdbPredicates = new relationalStore.RdbPredicates("test"); let resultSet = await store.query(predicates); // 查询所有数据 let result = collections.Array.create<SharedValuesBucket | undefined>(resultSet.rowCount, undefined) let index = 0; while (resultSet.goToNextRow()) { let v: IValueBucket = { id: resultSet.getLong(resultSet.getColumnIndex("id")), name: resultSet.getString(resultSet.getColumnIndex("name")), age: resultSet.getLong(resultSet.getColumnIndex("age")), salary: resultSet.getLong(resultSet.getColumnIndex("salary")) }; result[index++] = new SharedValuesBucket(v); } resultSet.close(); return result; }

通过Sendable可以有效减少数据传递过程中耗时，从而提高性能。