您需要将成员也放入类中，以便它确实实现接口:

You need to put the members in the class as well so that it will indeed implement the interface:

class ResultPage implements ResultPageInterface {
    public entries: Array<any>;
    public page_number: number;
    public page_size: number;
    public total_entries: number;

    constructor() {
        this.entries = [];
    }
}

您还可以将成员设为私有并使用 getter:

You can also have the members private and use getters:

class ResultPage implements ResultPageInterface {
    private _entries: Array<any>;
    private _page_number: number;
    private _page_size: number;
    private _total_entries: number;

    constructor() {
        this._entries = [];
    }

    public get entries() {
        return this._entries;
    }

    public get page_number() {
        return this._page_number;
    }

    public get page_size() {
        return this._page_size;
    }

    public get total_entries() {
        return this._total_entries;
    }
}