Typescript Class 使用接口作为类型而不是实现

Typescript Class use Interface as type instead of implement

我正在寻找模仿 using/implementing 接口的 C# 方式的方法。简而言之,我正在尝试复制以下代码:

interface EBook {
    function read();
}

class EBookReader {

    private $book;

    function __construct(EBook $book) {
        $this->book = $book;
    }

    function read() {
        return $this->book->read();
    }

}

class PDFBook implements EBook {

    function read() {
        return "reading a pdf book.";
    }
}

class MobiBook implements EBook {

    function read() {
        return "reading a mobi book.";
    }
}

使用工具效果很好,但我无法模仿 Class EBookReader 将电子书用作一种类型的方式。

codepen 和我的代码模型:http://codepen.io/Ornhoj/pen/gLMELX?editors=0012

using Ebook as a type

大小写敏感。

interface IEBook {
    read();
}

class EBookReader {
    book: IEBook;

    constructor(book: IEBook) {
        this.book = book;
    }

    read() {
        this.book.read();
    }

}

class PDFBook implements IEBook {
    read() {
        console.log("reading a pdf book.");
    }
}

class MobiBook implements IEBook {
    read() {
        console.log("reading a mobi book.");
    }
}
var pdf = new PDFBook();
var reader = new EBookReader(pdf);
reader.read();

测试此代码 in the playground