HarmonyOS 鸿蒙Next原生应用开发-从TS到ArkTS的适配规则（七）

一、不支持this类型

规则：arkts-no-typing-with-this

级别：错误

ArkTS不支持this类型，改用显式具体类型。

TypeScript

interface ListItem {
getHead(): this
}

class C {
n: number = 0
m(c: this) {
// …
}
}<button style="position: absolute; padding: 4px 8px 0px; cursor: pointer; top: 8px; right: 8px; font-size: 14px;">复制</button>

ArkTS

interface ListItem {
getHead(): ListItem
}

class C {
n: number = 0
m(c: C) {
// …
}
}<button style="position: absolute; padding: 4px 8px 0px; cursor: pointer; top: 8px; right: 8px; font-size: 14px;">复制</button>

二、不支持条件类型

规则：arkts-no-conditional-types

级别：错误

ArkTS不支持条件类型别名，引入带显式约束的新类型，或使用Object重写逻辑。

不支持infer关键字。

TypeScript

type X<T> = T extends number ? T: never
type Y<T> = T extends Array<infer Item> ? Item: never<button style="position: absolute; padding: 4px 8px 0px; cursor: pointer; top: 8px; right: 8px; font-size: 14px;">复制</button>

ArkTS

// 在类型别名中提供显式约束
type X1<T extends number> = T

// 用Object重写，类型控制较少，需要更多的类型检查以确保安全
type X2<T> = Object
// Item必须作为泛型参数使用，并能正确实例化
.type YI<Item, T extends Array<Item>> = Item<button style="position: absolute; padding: 4px 8px 0px; cursor: pointer; top: 8px; right: 8px; font-size: 14px;">复制</button>

三、不支持在constructor中声明字段

规则：arkts-no-ctor-prop-decls

级别：错误

ArkTS不支持在constructor中声明类字段。在class中声明这些字段。

TypeScript

class Person {
constructor(
protected ssn: string,
private firstName: string,
private lastName: string
) {
this.ssn = ssn;
this.firstName = firstName;
this.lastName = lastName;
}

getFullName(): string {
return this.firstName + ’ ’ + this.lastName;
}
}<button style="position: absolute; padding: 4px 8px 0px; cursor: pointer; top: 8px; right: 8px; font-size: 14px;">复制</button>

ArkTS

class Person {
protected ssn: string
private firstName: string
private lastName: string

constructor(ssn: string, firstName: string, lastName: string) {
this.ssn = ssn;
this.firstName = firstName;
this.lastName = lastName;
}
getFullName(): string {
return this.firstName + ’ ’ + this.lastName;
}
}<button style="position: absolute; padding: 4px 8px 0px; cursor: pointer; top: 8px; right: 8px; font-size: 14px;">复制</button>

本文根据HarmonyOS NEXT Developer Beta1官方公开的开发文档整理而成。