HarmonyOS 如何定义一个根容器

ArkTS支持TS5.0之前的TS装饰器语法。关于装饰器的定义和运行时行为，可以参考TS官方文档：https://www.typescriptlang.org/docs/handbook/decorators.html注意，如果在ets文件中定义装饰器，则需要同时满足ArkTS的语法规则，比如不能使用any等。以下是类装饰器、属性装饰器、方法装饰器、参数装饰器的简单示例：

function TestClassDecorator (target: Function) {}
function TestMemberDecorator (target: testClass, memberName: String) {}
function TestFunDecorator (target: testClass, propertyName: String, descriptor: PropertyDescriptor) {}
function TestArgDecorator (target: Function, methodName: String, paramIndex: Number) {}
@TestClassDecorator
class testClass {
@TestMemberDecorator
count: number = 123;
@TestFunDecorator
TestFun(@TestArgDecorator param: string) {}
}
请参考
import { MyDescriptor } from ‘…/common/decorators’
@Entry
@Component
struct Index_231129191721035 {
@State message: string = ‘Hello World’;
aboutToAppear() {
this.demo()
}
build() {
Flex() {
}
.backgroundColor(Color.Green)
.constraintSize({
minWidth: 100,
maxWidth: 200,
minHeight: 0,
maxHeight: 200
})
.height(‘100%’)
}
@MyDescriptor
demo() {
console.log(‘ccc’)
return ‘cccc’
}
}
export function MyDescriptor(target: Object, key: string, descriptor: PropertyDescriptor) {
const originalMethod: Function = descriptor.value
descriptor.value = (…args: Object[]) => {
console.log(Calling ${target.constructor.name} method ${key} with argument: ${args})
const result: Object = originalMethod(…args)
console.log(Method ${key} returned: ${result})
return result
}
return descriptor
}

装饰器装饰的类A，需要new A才能触发装饰器。