Question

我是TypeScript的新手。

为什么我收到此错误消息？

我不打算初始化抽象类。我打算在validatorMap字典中初始化一个IsEmptyValidator的具体类。

TS2511：无法创建抽象类的实例＆＃39; Validator＆＃39;

interface Dictionary<T> {
    [key: string]: T;
}

abstract class Validator {
    constructor() {
        console.log("super");
    }
}

class IsEmptyValidator extends Validator {
    public validate() {}

    constructor(){
        super();
        console.log("isEmpty");
    }
}

class ValidatorFactory {
    private validatorMap: Dictionary<Validator> = {
        "isEmpty": IsEmptyValidator
    };

    constructor() { }

    public create(validatorType: string) {
        let validatorToCreate: Validator = new this.validatorMap[validatorType];

        return validatorToCreate;
    }
}

Answer 1

你的词典没有实例Validator但是它的类，所以你应该这样做：

type ValidatorConstructor = {
    new (): Validator;
}

class ValidatorFactory {
    private validatorMap: Dictionary<ValidatorConstructor> = {
        "isEmpty": IsEmptyValidator
    };

    constructor() {}

    public create(validatorType: string) {
        let validatorToCreate: Validator = new this.validatorMap[validatorType]();

        return validatorToCreate;
    }
}

TS2511：无法创建抽象类的实例＆＃39; Validator＆＃39;

1 个答案: